KR20180068986A - A hydrophilic treatment agent and a hydrophilization treatment method - Google Patents

Abstract

A hydrophilic treatment agent capable of forming a hydrophilic film having a sufficiently high hydrophilicity and water resistance.
The polymer C1 having the basic unit A1 and the hydrophilic unit B1 constituting the basic skeleton and the basic unit A2 constituting the basic skeleton having a structure different from the basic unit A1 in the structure, And a polymer (C2) having a hydrophilic unit (B2). The base unit (A1) and the base unit (A2) are preferably one kind selected from polyurethane, polyester and polyvinyl alcohol.

Description

A hydrophilic treatment agent and a hydrophilization treatment method

The present invention relates to a hydrophilic treatment agent and a hydrophilic treatment method.

BACKGROUND ART Conventionally, there is known a technique of performing hydrophilization treatment on the surface of a metal substrate. For example, in a heat exchanger using aluminum, in order to prevent problems such as generation of noise due to condensed water adhering to the surfaces of the fins and contamination due to scattering of water droplets, hydrophilization treatment is performed on the surfaces of the fins A technique of forming a hydrophilic coating is known.

As a hydrophilic treatment agent used for the hydrophilic treatment, there has been proposed a hydrophilic treatment polymer composition containing a hydrophilic resin such as polyacrylic acid or polyethylene oxide (see, for example, Patent Document 1). This is a technique that improves the hydrophilicity of the hydrophilic coating. By including a hydrophilic resin in the hydrophilic treatment agent as described above, the hydrophilic property of the formed hydrophilic film can be improved.

Japanese Unexamined Patent Application Publication No. 6-322292

However, a product made of a metal base including an aluminum heat exchanger is required to be downsized. As the product made of the metal base material is miniaturized, the distance between neighboring metal base materials can be narrowed. When the distance between the metal substrates becomes narrow, for example, in a heat exchanger, clogging by water droplets occurs, and ventilation resistance tends to increase. Therefore, it is required that the surface of such a metal substrate is provided with hydrophilicity higher than conventionally required hydrophilicity.

Further, since the hydrophilic resin is easily dissolved in water, the hydrophilicity of the hydrophilic treatment agent tends to be lowered by the addition of the hydrophilic resin. The hydrophilic coating formed on the surface of the metal substrate is required to have high hydrophilicity as well as water resistance.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a hydrophilic treatment agent capable of forming a hydrophilic coating film having a sufficiently high hydrophilicity and water resistance.

The present invention relates to a base unit (A1) constituting a basic skeleton and a polymer (C1) having a hydrophilic unit (B1) (C2) having a hydrophilic unit (A2) and a hydrophilic unit (B2).

The base unit (A1) and the base unit (A2) are preferably one type selected from the group consisting of polyurethane, polyester and polyvinyl alcohol.

The hydrophilic unit (B1) and the hydrophilic unit (B2) are preferably polyethylene oxide.

The content of the hydrophilic unit (B1) in the polymer (C1) is 10 to 40 mass% and the content of the hydrophilic unit (B2) in the polymer (C2) is 10 to 40 mass% desirable.

The mass ratio (mass of the polymer (C2) / mass of the polymer (C1)) of the polymer (C2) to the polymer (C1) 9/1.

According to the present invention, it is possible to provide a hydrophilic treatment agent capable of forming a hydrophilic coating film having sufficiently high hydrophilicity and water resistance.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a graph showing the relationship between the mixing ratio of the polymer in the embodiment of the present invention and the water contact angle of the formed film. Fig.
2 is a graph showing the relationship between the mixing ratio of the polymer and the water contact angle of the formed film in the examples of the present invention.
3 is a graph showing the relationship between the mixing ratio of the polymer in the comparative example of the present invention and the water contact angle of the formed film.
4 is a diagram showing the results of XPS analysis in Comparative Example 1 of the present invention.
Fig. 5 is a diagram showing the results of XPS analysis in Comparative Example 4 of the present invention. Fig.
6 is a diagram showing the XPS analysis result in the first embodiment of the present invention.
Fig. 7 is a graph comparing peak areas showing hydrophilic units with respect to XPS analysis results of Figs. 4 to 6. Fig.

Hereinafter, an embodiment of the present invention will be described. The present invention is not limited to the following embodiments.

≪ Substrate (base material) >

Examples of the base on which a hydrophilic coating is formed on the surface of the hydrophilic treatment agent according to the present embodiment include a metal base, a glass base, a ceramics base, and a resin base. As the base material on which the hydrophilic coating is formed by the hydrophilic treatment agent according to the present embodiment, a metal base is preferable.

Examples of the metal base material include aluminum base materials. The aluminum substrate is a substrate made of aluminum. Here, " aluminum " is a general term for metals and alloys mainly made of aluminum, and includes concepts of pure aluminum and aluminum alloys.

As the aluminum base material, an aluminum heat exchanger can be mentioned. From the viewpoint of improving the heat exchange efficiency, the heat exchanger is arranged so that a plurality of fins are arranged at narrow intervals in order to make the surface area as large as possible, and the tubes for supplying the coolant are entangled with these fins.

<Hydrophilic treatment agent>

The hydrophilic treatment agent according to the present embodiment contains the polymer (C1) and the polymer (C2).

The polymer (C1) has a basic unit (A1) and a hydrophilic unit (B1) in its structure.

The basic unit (A1) constitutes the basic skeleton of the polymer (C1). The base unit (A1) is not particularly limited as long as it is a polymer having film-forming properties. Examples of the base unit (A1) include polyurethane, polyester, polyvinyl alcohol, and poly (meth) acrylic acid. The base unit (A1) is preferably one selected from the group consisting of polyurethane, polyester and polyvinyl alcohol. By using these polymers as the base unit (A1), the water resistance of the hydrophilic coating formed by the hydrophilic treatment agent is improved. It is more preferable that the base unit (A1) is polyurethane or polyester.

The hydrophilic unit (B1) is not particularly limited as long as it is a polymer having hydrophilicity. Examples of the hydrophilic unit (B1) include polyethylene oxide and polyvinyl pyrrolidone. The hydrophilic unit (B1) is preferably polyethylene oxide. When the hydrophilic unit (B1) is made of polyethylene oxide, the hydrophilic property of the hydrophilic film formed by the hydrophilic treatment agent is improved.

The content of the hydrophilic unit (B1) in the polymer (C1) is preferably 10 to 40% by mass. When the content of the hydrophilic unit (B1) in the polymer (C1) is less than 10% by mass, the hydrophilic property of the hydrophilic film tends to decrease, and when it exceeds 40% by mass, the water resistance of the hydrophilic film tends to decrease.

Here, the water contact angle of the hydrophilic coating formed only of the polymer constituting the hydrophilic unit (B1) is 30 DEG or less.

The structure of the polymer (C1) having the base unit (A1) and the hydrophilic unit (B1) is not particularly limited. The polymer (C1) is preferably a graft polymer or a block polymer of these units from the viewpoint of maximizing the properties of each unit of the base unit (A1) and the hydrophilic unit (B1). When the polymer (C1) is a graft polymer, either the base unit (A1) or the hydrophilic unit (B1) may be a branch.

The polymer (C2) also has a basic unit (A2) and a hydrophilic unit (B2) in its structure. The basic unit (A2) constitutes the basic skeleton of the polymer (C2).

The basic unit A2 has a different structure from the basic unit A1. In other words, the polymer (C1) and the polymer (C2) contained in the hydrophilic treatment agent according to the present embodiment are different from each other in basic units constituting these basic skeletons.

Like base unit A1, base unit A2 is not particularly limited as long as it is a polymer having film formability, but is preferably one selected from the group consisting of polyurethane, polyester and polyvinyl alcohol. That is, each of the main unit A2 and the basic unit A1 is preferably a different one selected from the group consisting of polyurethane, polyester and polyvinyl alcohol.

Similarly to the hydrophilic unit (B1), the hydrophilic unit (B2) is not particularly limited as long as it is a hydrophilic polymer, but is preferably polyethylene oxide. When the hydrophilic unit (B2) is made of polyethylene oxide, the hydrophilic property of the hydrophilic film formed by the hydrophilic treatment agent is improved. It is preferable that the hydrophilic unit (B1) and the hydrophilic unit (B2) constituting the polymer (C1) and the polymer (C2) contained in the hydrophilic treatment agent according to the present embodiment are the same polymer, Oxide.

The content of the hydrophilic unit (B2) in the polymer (C2) is preferably 10 to 40% by mass. When the content of the hydrophilic unit (B2) in the polymer (C2) is less than 10% by mass, the hydrophilic property of the hydrophilic coating tends to decrease, and when it exceeds 40% by mass, the water resistance of the hydrophilic coating tends to decrease.

Here, the water contact angle of the hydrophilic coating formed solely of the polymer constituting the hydrophilic unit B2 is equal to or less than 30 degrees, similar to the water contact angle of the hydrophilic coating formed only of the polymer constituting the hydrophilic unit B1.

The molecular weight (weight average molecular weight) of the polymer (C1) and the polymer (C2) is preferably 10000 to 1000000. When the molecular weights of the polymer (C1) and the polymer (C2) are less than 10,000, the water resistance of the formed hydrophilic coating tends to decrease. When the molecular weight exceeds 1000000, the handling property of the hydrophilic treatment tends to decrease.

The total content of the hydrophilic unit (B1) and the hydrophilic unit (B2) in the polymer (C1) and the polymer (C2) is preferably 10 to 40% by mass. When the total content is less than 10% by mass, the hydrophilic property of the hydrophilic film tends to decrease, and when it exceeds 40% by mass, the water resistance of the hydrophilic film tends to decrease.

The mass ratio of the polymer (C2) / the mass of the polymer (C1)) of the polymer (C2) relative to the polymer (C1) is from 1/9 to 9/1 . In other words, it is preferable that any basic unit of the polymer contained in the hydrophilic treatment agent is polyester.

When the base unit A1 is polyester, the mass ratio of the polymer (C2) to the polymer (C1) (mass of the polymer (C2) / mass of the polymer (C1)) is preferably 4/6 to 7/3 Is more preferable. As a result, not only the hydrophilic property of the formed hydrophilic film but also the persistence of the hydrophilic property is enhanced.

Examples of the polymer (C1) and the polymer (C2) include, for example, an ethylene oxide-modified polyester obtained by graft polymerizing ethylene oxide, And an ethylene oxide-modified polyurethane in which ethylene oxide is graft-polymerized to a polyurethane (base unit) obtained by polymerizing a diisocyanate. The polymerization method such as graft polymerization which is carried out when the polymer (C1) and the polymer (C2) are obtained is not particularly limited, and conventionally known methods can be used.

The hydrophilic treatment agent according to the present embodiment contains the polymer (C1) and the polymer (C2), which have different structures as described above, as compared with the hydrophilic treatment agent containing only one of the polymer (C1) and the polymer , The hydrophilic property of the formed hydrophilic film is remarkably improved. The mechanism by which the hydrophilic property of the formed hydrophilic coating is improved by containing both the polymer (C1) and the polymer (C2) is not clear. However, in the hydrophilic coating formed by the hydrophilic treatment agent according to the present embodiment, the polymer (C1) and the polymer (C2) are phase-separated at the molecular level and the base unit (A1) and the base unit , The hydrophilic unit (B1) and the hydrophilic unit (B2) are exposed to the surface side, thereby improving hydrophilicity.

It is presumed that the hydrophilic coating formed by the hydrophilic treatment agent according to the present embodiment improves the water resistance by orienting the base unit A1 and the base unit A2 to the base side as described above.

In the hydrophilic treatment agent according to the present embodiment, a pigment may be added for the purpose of forming a colored hydrophilic coating film. The pigment to be added is not particularly limited, and conventionally used colored pigments such as inorganic pigments and organic pigments can be used.

To the hydrophilic treatment agent according to the present embodiment, the following other components may be added in required amounts as desired. For example, hydrophilic treatment agents according to the present embodiment include hydrophilic additives such as surfactants, colloidal silica, titanium oxide, and saccharides; Rust inhibitors such as tannic acid, imidazoles, triazines, triazoles, guanines, hydrazines, phenol resins, zirconium compounds and silane coupling agents; Crosslinking agents such as melamine resin, epoxy resin, block isocyanate, amine, phenol resin, silica, aluminum and zirconium; Antibacterial agents, dispersants, lubricants, deodorants, solvents, and the like.

<Method of forming a hydrophilic film>

Next, a method of forming a hydrophilic film using the hydrophilic treatment agent according to the present embodiment will be described.

In the method for forming a hydrophilic film, it is preferable to clean the substrate with an acidic or alkaline detergent when treating the untreated aluminum substrate first. Examples of the acidic detergent to be used include nitric acid, sulfuric acid, hydrofluoric acid, and acidic aqueous solutions by the combination thereof. The acid concentration is preferably 1 to 10 N, more preferably 3 to 6 N. Further, a metal salt or a metal acid salt selected from iron, nickel, cobalt, molybdenum, and cerium may be added to the acidic cleaning agent.

Examples of the metal salt include iron sulfate, nickel sulfate, cobalt sulfate, cobalt sulfate ammonium, cerium sulfate, cerium sulfate ammonium, iron nitrate, cobalt nitrate, nickel nitrate, cerium nitrate, iron acetate, nickel acetate, cobalt acetate, Iron chloride, nickel chloride, cobalt chloride, molybdenum chloride, and cerium chloride. Examples of the metal salt include ammonium molybdate, potassium molybdate, and sodium molybdate.

The metal salt or metal salt is preferably added to the aqueous solution in an amount of 0.01 to 5% by mass. The metal salt or metal salt is preferably added to the aqueous solution in an amount of 0.1 to 1% by mass. When the metal salt or the metal acid salt is compounded in the above range, there is an advantage that the acid washing of the segregation due to the brazing material can be more effectively performed in the aluminum heat exchanger (evaporator or the like).

Examples of the alkaline detergent include an aqueous alkaline solution containing at least one of sodium hydroxide, sodium silicate and sodium phosphate. Surfactants can be added to the aqueous alkali solution to improve cleaning properties.

In order to clean a substrate made of aluminum, the above cleaning agent is sprayed or the substrate is immersed in a bath containing a cleaning agent. At this time, the liquid temperature of the cleaning agent is preferably 10 to 70 DEG C, and the contact time is preferably 30 seconds to 5 minutes. If the liquid temperature is less than 10 ° C or the contact time is less than 30 seconds, the removal of segregation or the like may be insufficient, and if it exceeds 70 ° C or exceeds 5 minutes, the etching may be excessive. It is preferable that the substrate after cleaning is rust-inhibited after water washing.

Examples of the rust-preventive treatment include a chemical conversion treatment and a substrate rust-preventive treatment with a resin primer. Among these, conventionally known chromic acid chromate treating agents, phosphoric acid chromate treating agents or non-chromium treating agents may be used as the chemical treating agent used in chemical conversion treatment. The chromate chromate treating agent is an aqueous solution containing chromic acid, fluoride and strong acid. Examples of the chromate chromate treatment agent include reactive chromate which is a main component of trivalent chrome, electrolytic chromate, and a coating type chromate in which hexavalent chromium and trivalent chromium are mixed. On the other hand, the phosphoric acid chromate treating agent is a mixed aqueous solution containing chromic acid, orthophosphoric acid and fluoride. When performing the conversion treatment by these chromate treatment agents, it is necessary to control each amount of hexavalent chromium ion, phosphate ion and fluoride ion.

Examples of the non-chromium treating agent include zirconium salts, titanium salts, silicic salts, boron salts and permanganate salts. Also, fluorides of these salts can be preferably used. In addition, acids such as phosphoric acid, manganese acid, permanganic acid, vanadium acid, tungstic acid, and molybdic acid may be added to these salts and fluorides.

As the resin primer, water-soluble or water-dispersible aqueous resins can be mentioned. Examples of these resins include water-soluble high-molecular compounds having a carboxyl group or a hydroxyl group such as poly (meth) acrylic acid, polyvinyl alcohol and carboxymethylcellulose, water-soluble phenol resins, water-soluble polyester resins, aqueous epoxy resins, .

The corrosion resistance of the formed film may be improved by adding an amount of 100 to 10000 ppm of a metal compound such as a zirconium compound (fluorozirconium acid, fluorozirconium ammonium, etc.) to the above resin primer.

The method of performing the anti-corrosive treatment is not particularly limited, and the anti-corrosive treatment can be performed by a dipping method, a spray method, or the like. When the aluminum heat exchanger is used as the base material, the aluminum heat exchanger has a complicated shape, and therefore, it is preferable to use the immersion method. The treatment temperature is preferably room temperature or slightly heated. The treatment temperature is, for example, 10 to 50 占 폚, and the treatment time is preferably 3 seconds to 5 minutes. As for the amount of the anticorrosion coating, it is preferable that the adhesion amount of each element (Cr, Zr, Ti, etc.) is 10 to 300 mg / m ² when the chemical conversion coating is formed. When the resin primer is used, it is preferable that the dried coating film thickness is 0.1 to 10 mu m by applying heat at 100 to 220 DEG C, preferably 150 to 200 DEG C for 10 to 60 minutes after the above treatment. If the heating temperature of the resin primer is less than 100 占 폚, the film-forming property of the resin primer becomes insufficient, and if it exceeds 220 占 폚, the hydrophilic continuity decreases. When the amount of the chemical conversion coating is less than 10 mg / m ² or the thickness of the resin primer coating is 0.1 탆, the rustproofing property tends to become insufficient, and when it exceeds 300 mg / m ² or 10 탆, it is economically disadvantageous. The base material is rinsed with water after the rust-preventive treatment, if necessary, and is used for hydrophilizing treatment.

The method of treating the base material with the hydrophilic treatment agent according to the present embodiment is not particularly limited, and a dipping method, a spraying method, a roll coating method, a soaking method, or the like can be employed as in the case of the treatment with a chemical treatment agent. When a base material having a complicated shape such as a heat exchanger is treated by a hydrophilic treatment agent, it is preferable to adopt a dipping method. The temperature of the treatment liquid is preferably 10 to 50 占 폚, and the treatment time is preferably 3 seconds to 5 minutes. Further, the coating amount is, 0.1 ~ 3g / m ² are preferred, more preferably 0.2 ~ 1g / m ^2. When the coating amount is less than 0.1 g / m ² , the hydrophilization performance tends to be difficult to be exhibited, while when it exceeds 3 g / m ² , the productivity tends to be lowered.

After the hydrophilic treatment, the hydrophilic film can be obtained by heating at a temperature of 100 to 220 ° C, preferably 150 to 200 ° C, for 10 to 60 minutes. When the heating temperature is lower than 100 ° C, the film-forming property tends to become insufficient. When the heating temperature is higher than 220 ° C, the hydrophilicity sustainability tends to decrease. In this manner, it is preferable that the substrate treated with the hydrophilic treatment agent according to the present embodiment has a hydrophilic coating formed with a coating amount of 0.1 to 3 g / m ² .

[ Example ]

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

&Lt; Preparation of hydrophilic treatment agent &

The components shown in Table 1, Table 2 and Table 3 were mixed with water at the ratios shown in the respective tables (the content (mass%) in the solid content of the hydrophilic treatment agent) using water to prepare each hydrophilic treatment agent. The components constituting the hydrophilic treatment agent were synthesized as follows.

<Synthesis of ethylene oxide modified polyester (EO-PE) 1>

Ethylene oxide was graft-polymerized on the polyester resin as the base resin. The amount of ethylene oxide to be polymerized was adjusted so that the content of polyethylene oxide in the resulting polymer was 10 mass%. The ethylene oxide modified polyester thus obtained was referred to as EO-PE1 (weight average molecular weight: 15000).

<Synthesis of ethylene oxide modified polyester (EO-PE) 2>

Ethylene oxide was graft-polymerized on the polyester resin as the base resin. The amount of ethylene oxide to be polymerized was adjusted so that the content of polyethylene oxide in the resulting polymer was 20 mass%. The ethylene oxide-modified polyester thus obtained was referred to as EO-PE2 (weight average molecular weight: 15,000).

<Synthesis of ethylene oxide modified polyester (EO-PE) 3>

Ethylene oxide was graft-polymerized on the polyester resin as the base resin. The amount of the ethylene oxide to be polymerized was adjusted so that the content of the polyethylene oxide in the produced polymer was 40% by mass. The ethylene oxide-modified polyester thus obtained was referred to as EO-PE3 (weight average molecular weight: 15,000).

<Synthesis of ethylene oxide-modified polyurethane (EO-PU) 1>

The polyurethane as the base resin was graft-polymerized with ethylene oxide. The amount of ethylene oxide to be polymerized was adjusted so that the content of polyethylene oxide in the produced polymer was 15 mass%. The ethylene oxide-modified polyurethane thus obtained was named EO-PU1 (weight average molecular weight: 800000).

<Synthesis of ethylene oxide-modified polyurethane (EO-PU) 2>

The polyurethane as the base resin was graft-polymerized with ethylene oxide. The amount of ethylene oxide to be polymerized was adjusted so that the content of polyethylene oxide in the resulting polymer was 12 mass%. The ethylene oxide-modified polyurethane thus obtained was referred to as EO-PU2.

<Synthesis of ethylene oxide modified polyurethane (EO-PU) 3>

The polyurethane as the base resin was graft-polymerized with ethylene oxide. The amount of the ethylene oxide to be polymerized was adjusted so that the content of the polyethylene oxide in the produced polymer was 10 mass%. The ethylene oxide-modified polyurethane thus obtained was referred to as EO-PU3.

&Lt; Synthesis of ethylene oxide-modified polyvinyl alcohol (EO-PVA) >

Vinyl acetate was graft-polymerized on polyethylene glycol as a base resin. Then, the polymer obtained by the graft polymerization was saponified to obtain an ethylene oxide-modified polyvinyl alcohol (weight average molecular weight: 45000). The amount of graft-polymerized vinyl acetate was adjusted so that the amount of polyethylene oxide contained in the finally obtained saponified polymer was 25 mass%. The ethylene oxide-modified polyvinyl alcohol thus obtained was referred to as EO-PVA.

The following components were used for components other than the components synthesized as described above.

Polyester (PE): A-120 (manufactured by Takamatsu Kogyo Co., Ltd.)

Polyurethane (PU1): HUX-550 (manufactured by ADEKA Corporation)

Polyurethane (PU2): HUX-386 (manufactured by ADEKA Corporation)

Polyvinyl alcohol (PVA): Clara Poval 105MC (made by Kuraray Co., Ltd.)

Polyacrylic acid: Jurima AC-10L (manufactured by TOA Corporation)

Polyacrylamide: Cholol AM-253P (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)

Polyethylene oxide (PEG1): ALKOX R-400Z (manufactured by Meisei Chemical Industry Co., Ltd.)

Polyethylene oxide (PEG2): Adeka PEG20000 (manufactured by ADEKA Corporation)

Defoaming agent 1: Hydropalat WE 3322 (manufactured by BASF)

Antifoaming agent 2: B2020 (manufactured by ADEKA Corporation)

Defoaming agent 3: Surfynol 104 (manufactured by Air Products)

<Preparation of Test Plates of Examples and Comparative Examples>

1000 series aluminum material (150 mm × 70 mm × 0.8 mm) was degreased at 70 ° C. for 30 seconds using a 3% solution of Surf Cleaner 322N8 (manufactured by Nippon Paint Surf Chemicals Co., Ltd.). Subsequently, the aluminum material was immersed in each of the hydrophilic treatment agents of Examples and Comparative Examples in which the content of solids in water was adjusted to 3 to 8 mass% with water and heated at 180 캜 for 10 minutes to solidify the hydrophilic coating. Each test plate thus obtained was used in the following evaluation. The solids content of the hydrophilic treatment agent was 6% by mass in Example 22 and Comparative Examples 26 to 31, 7% by mass in Comparative Examples 32 to 34 and 41 to 44 and 4% by mass in Comparative Examples 35 to 40, 3% by mass in Examples 11 to 15, and 8% by mass in the other Examples and Comparative Examples, respectively.

&Lt; Evaluation of hydrophilicity &

The contact angle of the test plate with water droplets was evaluated. The water contact angle was measured using an automatic contact angle meter (product number: DSA20E, manufactured by KRUSS). The contact angle measured is the contact angle between the test plate and the water droplet after 30 seconds from dropping in a room temperature environment. The evaluation criteria are as follows. The evaluation results are shown in Tables 1, 2, and 3. In particular, the contact angle with water droplets was measured on a test plate ("24h" in the table) immersed in an untreated test plate ("0h" in the table) and tap water (the amount of water was 15 kg / hour) for 24 hours and dried. When the contact angle is less than 10 DEG (evaluation &quot; A &quot;), it is considered that the hydrophilicity is good.

(Evaluation standard)

A: Water contact angle is less than 10 °

B: 10 ° or more, less than 30 °

C: 30 ° or more, less than 40 °

D: 40 ° or more

<Water resistance>

The test plate was immersed in tap water (the amount of water was 15 kg / hour) for 24 hours, pulled up, and dried, and the film remaining ratio was visually evaluated. The evaluation criteria are as follows. The evaluation results are shown in Tables 1, 2, and 3.

(Evaluation standard)

A: Remaining percentage of the film exceeds 85%

B: the film remaining ratio exceeds 80%, and not more than 85%

C: Cured film remaining ratio exceeds 70%, and 80% or less

D: Film remaining ratio of 70% or less

<Wet adhesion (initial coating)>

Spray pure water on the test plate and rub lightly with your fingers. One reciprocation was performed once to evaluate the number of times of rubbing until the hydrophilic coating was peeled off. The evaluation criteria are as follows. The evaluation results are shown in Tables 1, 2, and 3. When the number of times of rubbing until peeling exceeds 50 (evaluation "A"), it is evaluated that the WET adhesion is good.

(Evaluation standard)

A: The number of rubbing exceeds 50 times

B: The number of rubbing is more than 20 times, less than 50 times

C: Less than 20 rubs

&Lt; Coating surface analysis &

The hydrophilic coating formed by the hydrophilic treatment agent of Example 5 and Comparative Examples 1 and 4 was subjected to surface analysis by X-ray photoelectron spectroscopy (XPS) under the following conditions after the water resistance test. Specifically, the energy shift of the carbon orbital was analyzed to analyze information of chemical bonds including carbon existing on the surface of the coating film. The results are shown in Figs. FIG. 4 corresponds to the results of Comparative Example 1, FIG. 5 corresponds to Comparative Example 4, and FIG. 6 corresponds to the result of Example 5. In Figs. 4 to 6, the abscissa represents the binding energy (eV), and the ordinate represents the peak intensity (cps). 4 to 6 show peaks of CO (1s) attributable to ethylene oxide, dotted lines of fine lines indicate CC, dotted lines indicate C = O, and dash-dotted lines show peaks of OC = O . And a thick line indicates a peak summing the peaks of these carbon bonds.

(XPS measurement condition)

[Measurement apparatus] AXIS-NOVA (manufactured by Shimadzu Corporation)

[Measurement conditions] Lens mode: Field of View 1 Survey, Resolution: Passing energy 160 eV, Acquisition time: 217 seconds, Number of sweeps: 3, Anode: Monochrome X-ray (Al) 150W, Step: 100meV,

1 is a graph plotting the contact angle (hydrophilicity, after 0 hours of water flow) of the hydrophilic coating film formed with respect to the hydrophilic treatment agents of Examples 1 to 9 and Comparative Examples 1 and 4.

2 is a graph plotting the contact angle (hydrophilic property, after 72 hours of water retention) of the hydrophilic coating film formed with respect to the hydrophilic treatment agents of Examples 1 to 9 and Comparative Examples 1 and 4.

3 is a graph plotting the contact angle (hydrophilicity, after 0 hours water flow) of the hydrophilic coating film formed with respect to the hydrophilic treatment agents of Comparative Examples 1, 9 and 19 to 21. In Fig. 3, even when the hydrophilic coating film is exposed to oil water for a long time (for example, 72 hours), the contact angle is 40 DEG or more.

From FIG. 3, it can be seen that the hydrophilic coating formed from the hydrophilic treatment agents of Examples 1 to 9 is higher in hydrophilicity than the hydrophilic coating formed by the hydrophilic treatment agents of Comparative Examples 1 and 4. From these results, it can be concluded that a polymer having a basic unit constituting the basic skeleton and a hydrophilic unit in its structure is contained in a plurality of types It was confirmed that the hydrophilic property of the hydrophilic coating film to be formed becomes higher in the case of the hydrophilic treatment agent. In addition, the hydrophilic coatings formed from the hydrophilic treatment agents of Examples 1 to 9 are also excellent in water resistance.

As shown in Fig. 3, even if a polymer having no hydrophilic unit is mixed with a polymer having a basic unit and a hydrophilic unit in the structure constituting the basic skeleton, the hydrophilic film hydrophilic property formed is not improved.

As shown in Fig. 2, when the formed hydrophilic coating film is exposed to oil water for a long time, the hydrophilicity tends to decrease. However, when the base unit A1 is polyester and the polymer C2 for the polymer (C1) (Mass of the polymer (C2) / mass of the polymer (C1)) is 4/6 to 7/3, the hydrophilicity persistence is also increased.

Fig. 7 is a graph showing the relationship between the peak area CO of CO (1 s) due to ethylene oxide and the peak area C of the entire carbon orbit in the surface analysis by XPS in Comparative Examples 1, 4, and 5 in Figs. Area ratio.

From FIG. 7, although the total content of ethylene oxide was the same in Example 5 and Comparative Examples 1 and 4, the ratio of ethylene oxide existing on the surface of the hydrophilic coating of Example 5 was the same as that of the hydrophilic coatings of Comparative Examples 1 and 4 Is greater than the proportion of ethylene oxide present on the surface of the catalyst.

From this result, it can be seen that the hydrophilic coating formed by the hydrophilic treatment agent of Example 5, which contains a plurality of polymers having a basic unit and a hydrophilic unit in the structure, constituting the basic skeleton, is exposed to the surface side of the hydrophilic unit, It was confirmed that good hydrophilicity was obtained.

Claims (5)

In the structure, a polymer (C1) having a basic unit (A1) and a hydrophilic unit (B1) constituting a basic skeleton,
And a polymer (C2) having a basic unit (A2) and a hydrophilic unit (B2) constituting a basic skeleton different in structure from the basic unit (A1). The method according to claim 1,
Wherein the base unit (A1) and the base unit (A2) are each one type selected from the group consisting of polyurethane, polyester and polyvinyl alcohol. 3. The method according to claim 1 or 2,
The hydrophilic unit (B1) and the hydrophilic unit (B2) are polyethylene oxide. 4. The method according to any one of claims 1 to 3,
The content of the hydrophilic unit (B1) in the polymer (C1) is 10 to 40% by mass,
The content of the hydrophilic unit (B2) in the polymer (C2) is 10 to 40% by mass. 5. The method according to any one of claims 1 to 4,
The base unit (A1) is a polyester,
The mass ratio of the polymer (C2) to the polymer (C1) (mass of the polymer (C2)
/ Mass of the polymer (C1)) is 1/9 to 9/1.

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