JPH03254864A - Hydrophilicity imparting treatment - Google Patents

Abstract

PURPOSE:To obtain a film improved in wettability even when a volatile lubricant is used as processing oil by adding a specific amount of a surfactant having a specific HLB value to a topcoating treatment agent forming a hydrophilic film or adding a specific amount of the volatile lubricant thereto. CONSTITUTION:In the hydrophilic treatment of a metal member subjected to molding processing using a volatile lubricant, a surfactant with HLB of 8-45 is preliminarily added to a hydrophilic film before molding processing during hydrophilicity imparting topcoating treatment so that 0.04-2.5wt.% of the surfactant is present in the volatile lubricant. At first, the hydrophilic film is formed before molding processing and, next, processing oil prepared by adding 0.04-2.5 pts.wt. of the surfactant with HLB of 8-45 to 100 pts.wt. of the volatile lubricant is used. By this method, the lowering of wettability due to the volatile lubricant can be prevented. Therefore, a fin having good hydrophilicity can be prepared even from a precoated aluminum thin plate material for the cross fins of a heat exchanger.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for hydrophilizing metal members including aluminum materials such as aluminum fin materials for heat exchangers, and more specifically, to a method for making metal members having a hydrophilic film. Even if volatile lubricating oil is used as processing oil in the forming process of metal parts,
This invention relates to a treatment method that does not reduce the water wettability of a hydrophilic film.

[Conventional technology]

Aluminum and its alloys are lightweight and have excellent workability and thermal conductivity, and are widely used in heat exchangers and the like.

BACKGROUND ART With the spread of air conditioning systems, the number of air conditioners that can be used for cooling, dehumidification, and heating and cooling has increased, and aluminum alloy fins are generally used in the heat exchange parts of these air conditioners.

During cooling operation of an air conditioner, moisture in the air tends to adhere to the fin surface as condensed water. To prevent this, it is possible to make the surface of the fins water-repellent, but if this is done, the condensed water will adhere to the fins in a hemispherical shape or exist in the form of bridges between the fins, which will prevent the smooth flow of air. and increase ventilation resistance. Since making the fin surface water repellent in this way will conversely reduce the heat exchange efficiency, the fin surface is treated to have hydrophilic properties.

Processing oil is applied to the pre-coated fin material on which a hydrophilic film has been formed during molding for the purpose of improving processing workability and protecting the surface of the fin material. Traditionally, this processing oil was removed using fluorocarbons as a cleaning agent in the degreasing process after molding, but in recent years, the use of fluorocarbons has been regulated due to environmental issues, and processing methods that do not use fluorocarbons are becoming more and more popular. It has become possible to do so. Therefore, volatile lubricating oils that do not require a cleaning process have come to be used as lubricating oils for processing fin materials.

[Problem to be solved by the invention]

However, it has been found that when volatile lubricating oil is used, the water wettability of the hydrophilic film decreases. This is thought to be because a small portion of the ester-based oiliness improver or impurities contained in the volatile lubricating oil remain on the surface of the fin material without being volatilized, which reduces water wettability.

Therefore, an object of the present invention is to provide a hydrophilic treatment method that solves the above-mentioned problems and can provide a hydrophilic film with sufficient water wettability even when volatile lubricating oil is used as processing oil. It is.

[Means to solve the problem]

As a result of intensive research in view of the above purpose, the present inventor has discovered that a specific H.
If you use a surfactant with an LB value and add it in a specific amount to the top coating treatment agent that forms a hydrophilic film, or if you add it in a specific amount to the volatile lubricating oil used as processing oil, water-wetting will be avoided. They discovered that it is possible to obtain a hydrophilic film with good properties, and completed the present invention.

That is, in the first hydrophilic treatment method of the present invention for a metal member to be molded using volatile lubricating oil, a hydrophilic film is formed before molding, and at that time, the amount of the volatile lubricating oil is reduced to 0.
．． A surfactant with an HLB of 8 to 45 should be added to the hydrophilic topcoat so that 04 to 2.5% by weight of the surfactant is present in the hydrophilic film. Features.

In addition, in the second hydrophilic treatment method of the present invention, a hydrophilic film is formed before molding, and then 0.04 parts of a surfactant with an HLB of 8 to 45 is added to 100 parts by weight of volatile lubricating oil. ~2.5
The method is characterized in that the metal member is formed using a processing oil containing a weight part of the processing oil.

Furthermore, in the third hydrophilic treatment method of the present invention, after forming a hydrophilic film using the hydrophilic top coat treatment agent to which a surfactant is added in the first method, a surfactant is also added to the volatile lubricant. The method is characterized in that the metal member is formed using a processing oil produced by:

The present invention will be explained in detail below.

The surfactant used in the present invention may be any surfactant as long as it can emulsify and disperse volatile lubricating oil in water, but nonionic surfactants or anionic surfactants are preferable, and nonionic surfactants are more preferably used. For example, polyethylene glycol type surfactants include higher alcohol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, higher alkylamine ethylene oxide adducts, fatty acid amide ethylene oxide adducts, Polypropylene glycol ethylene oxide adducts and the like can be used. Furthermore, examples of polyhydric alcohol types include fatty acid esters of sucrose.

Specific examples of surfactants that can be used include the following.

(A) Polyethylene glycol type surfactant (a) Higher alcohol ethylene oxide adduct Examples of the general formula include the following.

R-0-(CH2CII20) ,,H where R:C,
, ~C+a R,: C7 to C9 n Generally 8 to 15 Products include Adecatol LO series, Adecatol SO series (manufactured by Asahi Denka), Emulgen series (manufactured by Kao), Neugen ET, EA series (No. Industrial Pharmaceutical Flavor Department) etc. can be used.

et al.) Fatty acid ethylene oxide adduct Examples of general formulas include the following.

R-Coo-(CH,CH20), H where R:C,
□~C1n generally 5~30 As commercial products, Adekator oEG series (manufactured by Asahi Denka ■), Emanone series (manufactured by Kao ■), Neugen ES series (manufactured by Daiichi Kogyo Seiyaku ■), etc. can be used.

(C) Polyhydric alcohol fatty acid ester ethylene oxide adduct Here, R: C, 2 to CI8, and also includes diesters and the like in addition to the above.

As a product, ADEKA NOL NK series (manufactured by Asahi Denka)
, Rheodol TW series or No. 400 series (manufactured by Kao ■), Sorgen TW series (manufactured by Daiichi Kogyo Seiyaku ■), etc. can be used.

(d) Higher alkylamine ethylene oxide adduct Examples of the general formula include the following.

Oxyethylene alkylamine RNH (CH, CH2O) ,,H where, R: c, 2~Cl8 n, m: O~20 Polyoxyethylene alkylamide n: about 15~50 Products include Pluronic series, Adekanol B series (Manufactured by Asahi Denka) EMARUKEN PP series (
Epan series (manufactured by Kao ■) (manufactured by Dai-Kogyo Seiyaku Ajibu), etc. can be used.

(B) Polyhydric alcohol type Fatty acid ester type of sucrose General formulas include the following.

Here, R: C, .about.Cl8 nS m : 0 to 20 As commercial products, Amit series (manufactured by Kao ■), Amiradin series (manufactured by Dai-Kogyo Pharmaceutical Flavor Department), etc. can be used.

(e) Polypropylene glycol ethylene oxide adduct General formulas include the following.

HO(CH,C11,0), (CH2CHCH20).

(CI(, CLO) ,, H where m+n+m'
= 20 ~ 80 1 (011C-CI (0)! Here, R: 0.2 ~ mouth 1 ° As a product, Span, Emulgen series (Kao (5)
(manufactured by) etc. can be used.

The HLB of the surfactant used in the present invention must be in the range of 8 to 45. HLB is a value indicating the ratio of the parent wood part to the lipophilic part in one molecule of surfactant, and a large HLB indicates a large hydrophilic property, and a small HLB indicates a large lipophilic property. In the present invention, HLB has a hydrophilic portion of polyoxyethylene or polyhydric alcohol,
RIFFIN Ujisada II (Surfactant Handbook, 1966,
According to Sangyo Tosho Publishing, p. 307), hydrophilic parts other than those listed above are defined by Mr. DAVIS (same as above, 3).
(page 13). If the HLB is less than 8, the volatile lubricating oil residue cannot be sufficiently emulsified and dispersed, and the resulting film will not have sufficient water wettability. on the other hand,
If the value exceeds 45, the processing liquid may foam.
A good hydrophilic film cannot be formed.

The amount of surfactant is 0.04 to 2.5% by weight of the volatile lubricating oil that adheres to the member to be molded.

That is, in the first method of the present invention using a hydrophilic top coating treatment agent containing a surfactant, for example, if a volatile lubricating oil is applied at 10 g/m' during molding, the formed hydrophilic Surfactant in the film is 0.004
The concentration of surfactant in the hydrophilic topcoat is set to be present at ~0.25 g/m'. In addition, in the second method of the present invention in which a surfactant is added to a volatile lubricating oil, 0.04 to 2.5 parts by weight of a surfactant is added to 100 parts by weight of a volatile lubricating oil. Used as processing oil.

In a third method of the invention, the total amount of surfactant is 0.04 to 2.5% by weight of the amount of volatile lubricating oil.

When the amount of surfactant is as small as less than 0.04% by weight relative to the volatile lubricating oil attached to the part, it is necessary to sufficiently emulsify and remove the ester oil improver and impurities remaining on the surface of the part.
It cannot be dispersed and has poor water wettability. Moreover, if the amount of surfactant exceeds 2.5% by weight, water condensed on the surface of the hydrophilic film will foam, which will reduce the heat exchange efficiency of the aluminum fin material, which is not preferable.

In addition, the preferred amount of the surfactant of the present invention is 1 to 2% by weight of the amount of volatile lubricating oil deposited in the first method,
In the second method and third method of the present invention, 0.5 to
It is 2% by weight.

The volatile lubricating oil used in the present invention may be any commercially available low-viscosity aluminum fin processing oil (paraffin-based lubricating oil) with excellent drying properties, such as Daphne Punch Oil AF.
-2A, Daphne Punch Oil AP-4A (both manufactured by Idemitsu Petrochemical), etc. can be used.

In addition, as a hydrophilic top coating treatment agent, for example, sodium salt of carboxymethylcellulose and/or
Alternatively, a hydrophilic top coating agent containing 5 to 25 parts by weight of a potassium salt, 25 to 50 parts by weight of an ammonium salt of carboxymethylcellulose, and 25 to 70 parts by weight of N-methylolacrylamide can be used. Moreover, in addition to the above components, it may further contain polyacrylic acid and a zirconium compound. In this case, the content of polyacrylic acid is 1.5 to 15 parts by weight, and the content of zirconium compound is 0.6 to 9 parts by weight (as 2r) with respect to a total of 100 parts by weight of the above components. It's good. In addition, the hydrophilic top coating treatment agent may contain other antifungal agents, preservatives, solid lubricants, etc., as appropriate.

A method for forming a hydrophilic film on a metal member such as an aluminum material can be performed, for example, as follows.

First, a metal member is degreased. The degreasing treatment may be either solvent degreasing using trichlorethylene, perchlorethylene, gasoline, n-hexane, etc., or alkaline degreasing using alkaline earth metals such as sodium hydroxide, sodium carbonate, sodium silicate, sodium phosphate, etc.

Next, the degreased metal member is washed with water, dried, and subjected to a brimer treatment. For this purpose, chromate treatment, treatment with a zirconium treatment agent, treatment method of coating with phenol resin or melamine resin, etc. can be applied.

The parts that have been treated with brimer are dried and a hydrophilic topcoat treatment agent is applied.

In the first method and the third method of the present invention, as described above, a predetermined amount of surfactant is used in the hydrophilic top coating treatment agent. It is advisable to sufficiently perform this mixing using a disper or the like.

On the other hand, in the second method of the present invention, a hydrophilic topcoat treatment agent that does not contain a surfactant is applied.

In all of the above three methods, the coating amount of the hydrophilic top coating treatment agent is preferably 0.05 to 0.4 g/m' in the dry film. If the hydrophilic film is less than 0.05 g/m', it is difficult to maintain good hydrophilicity;
If the amount exceeds g/m', it is not preferable because it increases the cost and also causes poor adhesion between the coating layer and the base material (or the brimer layer).

After hydrophilic treatment is performed and the film is dried, volatile lubricating oil is applied to the member and molding is performed.

In the first method of the invention, a conventional volatile lubricating oil without surfactants is used. On the other hand, in the second and third methods of the present invention, as described above, volatile lubricating oil containing a predetermined amount of surfactant is applied.

The amount of volatile lubricating oil applied is usually in the range of 1 to 20 g/m'. Note that this coating method can be appropriately selected from a spray method, a brush coating method, a dipping method, and the like.

[For production]

When molding is performed using volatile lubricating oil as processing oil, the water wettability of the hydrophilized formed member decreases because a small portion of the components or impurities in the oiliness improver of the volatile lubricating oil volatilize. It is thought that this is a bond that remains on the surface of the film. Therefore, if a surfactant is added to at least one of the hydrophilic film and the volatile lubricating oil, when dew condenses on the film, the residue can be emulsified and dispersed in the condensed water. Deterioration of water wettability of the film can be prevented.

By limiting the HLB of the surfactant used and adding a specific amount of surfactant that matches the amount of volatile lubricating oil used, good water wettability can be obtained and surface treatment can be achieved. It can prevent foaming of bath water and condensed water.

〔Example〕

The present invention will be explained in more detail by the following specific examples.

Example 1 Aluminum fin material (0,1110!OX 200mmX
300 mm) was degreased using an alkaline degreaser (Surf Cleaner 322N-8, manufactured by Nippon Pain Co., Ltd.) under the following conditions.

Surf cleaner concentration (aqueous solution) 1.0% by weight
Every time
After degreasing for 5 seconds at 65° C., it was washed with tap water and dried.

Next, a resin-based brimer (Surf Alcoat 460, manufactured by Nippon Paint ■) was applied by a roll coating method. The coating amount at this time was 5 g/m' (Ig/rn as resin content)
')Met. This was baked at 240°C for 30 seconds.

A surfactant (Emulgen 420
, manufactured by Kao ■) and 1 part by weight using a disper.
The mixture was stirred for 0 minutes to obtain a hydrophilic treatment liquid.

This treatment liquid was applied by roll coating to the pre-coated aluminum fin material which had been subjected to the above-mentioned brimer treatment. The coating amount was 5 g/m'.

After applying the treatment liquid, it was baked at 220° C. for 15 seconds to obtain a test piece.

A water wettability evaluation test and a foamability evaluation test were conducted on the test piece obtained by the above operation in the following manner.

(1) Water wettability evaluation test A test piece cut into 10 cm x 10 cm was coated with volatile lubricating oil (Daphne Punch Oil AF-2A).

Idemitsu petrochemical type) by roll coating method.
m' and left in the air at 25°C to dry.

After 24 hours, the test piece was immersed in water for 3 seconds, and the water wetness rate immediately after taking it out was evaluated according to the following criteria. Note that the water wettability represents the ratio of the area of the portion where water remains (the portion with water) to the area of a 10 cm x 10 mark test piece.

Water wettability evaluation 100% ◎ 95% to 100%: ○ 85% to less than 95%: △ Less than 85% ・ × (2) Foamability evaluation test Volatile lubricating oil (same as above) was applied to the log by roll coating /
m'', left in the air at 25°C, dried, and cut into a size of 1 cm x 10 cm.

Put 20 of these test pieces into a 200-meter cylinder,
Furthermore, pure water was added, and the test piece was immersed in the pure water. After shaking this for 10 minutes using a shaker, it was allowed to stand still for 30 seconds, and the height of the bubbles (from the water surface) at that time was measured.

The evaluation criteria are as follows.

Foam height rating Less than 20m: 0 2 cm or more and less than 30 m: △ 3 cm or more: × The results of each test are shown in Table 1.

Examples 2 to 12 Type of surfactant, amount relative to volatile lubricant, amount of oil applied,
Water wettability and foamability were evaluated in the same manner as in Example 1, except that the and HLB values were changed as shown in Table 1. The results are also shown in Table 1.

Comparative Examples 1 to 4 For comparison, no surfactant was added to the hydrophilic treatment agent (
Comparative Example 1), those with a low surfactant content (Comparative Example 2), those with a high surfactant content (Comparative Example 3), and those with an HLB value outside the range of 8 to 45 ( Regarding Comparative Example 4), water wettability and foamability were evaluated in the same manner as in Example 1.

The results are shown in Table 3.

Examples 13 to 24 The aluminum fin material used in Example 1 was also degreased, washed with water, dried, and subjected to primer treatment in the same manner as in Example 1.

A hydrophilic treatment agent (Surf Alcoat 160, manufactured by Nippon Paint ■) was applied to this by a roll coating method. The coating amount was 5 g/m'.

This was baked at 220° C. for 15 seconds to obtain a test piece.

Volatile lubricant (
A mixture of the surfactants shown in Table 2 was applied to Daphne Punch Oil AP-2A (manufactured by Idemitsu Petrochemical) and dried.

The obtained test piece was subjected to a water wettability evaluation test and a foamability evaluation test in the same manner as in Example 1.

The results are shown in Table 2.

Comparative Examples 5 to 8 Test pieces having hydrophilic films were prepared in the same manner as in Example 13.

Using this test piece, a volatile lubricating oil containing no surfactant was applied and dried (Comparative Example 5), a volatile lubricating oil with a low surfactant content was used (Comparative Example 6),
Those using volatile lubricating oils with high surfactant content (
Comparative Example 7) and one using a surfactant with an HLB value outside the range of 8 to 45 (Comparative Example 8) were prepared, and the water wettability and foamability were evaluated in the same manner. The results are shown in Table 3.

Examples 25 to 30 In the same manner as in Example 3, a hydrophilic treatment liquid containing a surfactant was applied and dried in the same manner, and the surfactant corresponding to Examples 13 to 18 was added to a volatile lubricant. The mixture was applied and dried. The correspondence of surfactants is as follows.

Example 25 Example 13 Example 26 Example 14 Example 27 Example 15 Example 28 Example 16 Example 29 Example 17 Example 30 Example 18 The obtained test pieces were tested in the same manner as in Example 3. I did it. The results were ◎ in all water wettability evaluation tests and ○ in all foamability evaluation tests.

[Effect of Hathu]

As detailed above, according to the method of the present invention, it is possible to prevent a decrease in water wettability due to volatile lubricating oil, and the resulting hydrophilic film exhibits good hydrophilicity.

Therefore, by using the method of the present invention, good fins with sufficient hydrophilicity can be manufactured even when volatile lubricating oil is used as processing oil for pre-coated thin aluminum sheets for cross fins of heat exchangers. .

The method of the present invention can be applied not only to processing cross fin materials of heat exchangers, but also to other metal parts using volatile lubricating oil as processing oil.

Entry to Hatake Nippon Paint Co., Ltd.

Claims (1)

[Scope of Claims] In a method for hydrophilizing a metal member that is molded using a volatile lubricating oil, (a) when forming a hydrophilic film before molding, 0.00% of the amount of the volatile lubricating oil is used. A step of adding a surfactant having an HLB of 8 to 45 to the hydrophilic topcoating agent in advance so that 04 to 2.5% by weight of the surfactant is present in the hydrophilic film, or (b) molding. A hydrophilic film is formed before processing, and then a processing oil is prepared by adding 0.04 to 2.5 parts by weight of a surfactant having an HLB of 8 to 45 to 100 parts by weight of a volatile lubricating oil. A hydrophilic treatment method characterized by performing at least one of the following two steps: forming a metal member.