JPS6069169A - Hydrophilic film forming agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydrophilic film-forming agent that provides a hydrophilic film on the surface of materials such as metals and plastics.

Hydrophilic film-forming agents are used to prevent the formation of condensed water droplets on the surface of a material, and to prevent charging or clouding of the surface of the material by providing a hydrophilic film on the surface of the material.

Among these purposes, for example, in the case of heat exchangers, measures are taken to increase the fin density to increase heat exchange efficiency, but increasing the fin density causes condensed water droplets to block the fin space and increase ventilation resistance. Because of this tendency, the development of high-level hydrophilic films is expected.

A known method for obtaining such a hydrophilic film is, for example, adding silica particles or a surfactant as a hydrophilicity imparting agent to a resin paint, but in the former method, the material after the film is formed is subjected to die molding, etc. When applied, there is a problem that the die is abraded, and the latter has the disadvantage that the surfactant is eluted over time, resulting in deterioration of hydrophilicity.

In view of these current circumstances, the present invention has been developed to form a new hydrophilic film that is hydrophilic and has extremely little deterioration over time, and also has less die wear due to the film formed during molding, and can be used for antistatic, anti-fogging, etc. This paper proposes a new drug.

The inventor discovered that ion exchange resins are essentially insoluble in water, and that their exchange groups are hydrophilic and have a strong ability to draw in water from the outside, and that if ion exchange resins are dispersed in resin paints, an excellent hydrophilic film can be formed. The inventors came up with the idea that a forming agent could be obtained, and after conducting various studies, completed the present invention.

The gist of the present invention is to disperse ion-exchange resin powder in a resin coating consisting of coating film components - for example, natural resins such as alkyd resins and synthetic resins such as acrylic resins - and film-forming auxiliary elements. The coating film component consists of a coating film forming element and a coating film side element (however, if necessary), and no pigment is added from the viewpoint of the purpose of the present invention.

As the coating film components, those conventionally used for resin coatings can be selected from among the plasticized synthetic resins and thermosetting synthetic resins, but depending on the usage conditions of the product to which the hydrophilic film is applied and In consideration of the stability of the ion exchange resin, thermoplastic resins preferably have a softening temperature of 80° C. or higher. In the case of thermosetting resins, the baking of the paint film will occur if the heating time exceeds 10 minutes, and the curing temperature of stool fat is 150'.
It is preferable to select a resin with a curing temperature of 150° C. or higher, and when using a resin with a curing temperature of 150° C. or higher, it is preferable to use a heating method that takes a heating time of 1 minute or less for baking.

Resins in coating film components that are compatible with these conditions include alkyd resins, acrylic resins, polyvinyl alcohol resins, vinyl acetate resins, and epoxy resins.

Examples include phenol resin, polyester resin, urethane resin, etc., but are not limited thereto.

In addition, this film-forming agent contains water in the case of water-based paints, and hydrocarbons, alcohol, alcohol, As in the case of ordinary paints, suitable materials such as esters, ketones, and ethers can be used depending on the characteristics of the resin used.

In addition, the amount of these media added can be arbitrarily selected within an appropriate range in order to develop fluidity depending on the application method, just like in ordinary paints, and depending on the desired hydrophilicity level. However, it can be selected within an appropriate range.

(3) As an ion exchange resin, styrene or methacrylic acid is copolymerized with divinylbenzene as a crosslinking agent, and the hydrophilic atomic groups include sulfonic acid groups, carboxylic acid groups, phosphonic acid groups, and phosphinic acid groups. Those to which quaternary ammonium, primary or tertiary amines have been added are often used as cation exchange resins and anion exchange resins. Exchange capacity per gram (g) of exchange resin is 2.0 [:
meqJg-Dry-R)] are preferably used for the present invention. If it is less than 2 pO, the required wettability cannot be sufficiently ensured.

Note that phenolic resin-based resins can also be used as long as they are insoluble as ion exchange resins and have surfactant properties.

Among these ion exchange resins, cation exchange resins (including salt types substituted with alkali metals) are suitable for application because they are highly hydrophilic, and sulfonic acid type strongly acidic cation exchange resins are more suitable. Optimal.

Depending on the desired hydrophilicity level, a mixture of a strongly acidic cation (4) exchange resin and a weakly acidic cation exchange resin, a mixture of a highly basic ion exchange resin and a weakly basic ion exchange resin, or a cation exchange resin It is also possible to apply a mixture of two or more types of anion exchange resin and anion exchange resin in coexistence.

Commercially available ion exchange resins are usually in the form of granules of 10 to 50 mesh, and are used after being pulverized depending on the desired film thickness. In other words, since the normal film thickness is about 0.5 μm to 3 μm, it is necessary to take into account the smoothness of the film, the homogeneity of the film, etc., and grind it to an average particle size of 1 μm or less. served. In that case,
Of course, if a finely pulverized product is available for special purpose analysis or ultra-high purity use, it can be used as is. Further, it is also possible to use a method of adjusting the final particle size to a desired size by secondary use of the kneading process with the resin paint.

The amount of ion exchange resin added to the coating film components in this film forming agent should be determined appropriately depending on the exchange capacity of the ion exchange resin itself and the desired hydrophilicity level for the film to be formed. However, it is necessary that the proportion of ion exchange resin in the total amount of coating film components and ion exchange resin powder is α1 or more on a dry weight basis (hereinafter, the above proportion is referred to as "exchange resin"). ).

When the exchange resin ratio is 0.01 or less, it becomes difficult to stably obtain a desired hydrophilicity level. The exchange resin ratio is preferably in the range of 03 to α7.

If α7 or more, the adhesion to the purple background is poor.

For example, when using this film-forming agent for antistatic purposes that require only hydrophilicity, the exchange resin ratio is preferably α5 or more, and when hydrophilicity and die processability are particularly required, It is preferable that the exchange resin ratio is 0.03 or more. In addition, when applied to prevent fogging of plastic materials, it is possible to use products with an exchange resin ratio of about 02.

In addition, the solvent of the coating film forming auxiliary element may be added to the mixed stock solution of coating film components and ion exchange resin at the time of use, or may be used in the form of adding and mixing the champion from the beginning, etc. added to.

Furthermore, the present film-forming agent allows the addition of various additives that impart various properties as a coating material. Namely, dispersants, anti-mold agents, and anti-skinning agents.

A slip agent, an antifoaming agent, etc. may be contained in an amount of about 1 to 2% each, if desired. Furthermore, it is not prohibited to add, for example, 2 to 3% of a surfactant as an initial hydrophilicity improver for the present film forming agent.

Next, the manner in which the present film-forming agent is used will be described. Application methods for ordinary paints, ie, roll coating, spraying, dipping, brushing, spin-coating, etc., are applicable. If the paint is an air-drying paint, the film is fixed by air drying after application, and if it is a baking type paint, baking is performed under appropriate heating conditions that do not impair the properties of the ion exchange resin.

It is also an effective means to use a base film treatment (for example, chromate treatment, etc.) as a pretreatment for the film forming treatment in order to improve the anticorrosion properties of the base surface and the adhesion of the film.

As mentioned above, regarding the hydrophilic film forming agent according to the present invention (7) 1, the film formed by the water agent is hydrophilic and has extremely little deterioration due to long-term use. It has characteristics such as less die wear. Therefore, it is suitable as a hydrophilic film-forming agent for fin members for heat exchangers with high-density fins, and it also forms a film with unprecedented hydrophilic sustainability, and is useful for antistatic, anti-fogging, etc. can also be used.

Hereinafter, embodiments and usage modes of the present invention will be described in detail with further examples.

Example 1 Commercially available sulfonic acid type polystyrene cation exchange resin:
4.5 Cmeq/(g-Dry-R)] (]
Amberlite IR-420 (manufactured by Om & Haas Co., Ltd.) was ground in a vibrating ball mill for about 30 minutes and dried with an infrared lamp. First, 200 g of this fine powder and an epoxy ester water-soluble paint (manufactured by Dainippon Ink Co., Ltd.) were obtained, with an average particle size of 15 μm and a water content of 12%.

Water 1-/L 5-352 ;゛Solid content 46%) 650
g.

(18) 100 g of butyl cellosolve and 4 oo g of water were placed in a pot mill and kneaded for about 6 hours to ensure uniform dispersion of each. As a result, the secondary particle diameter of the ion exchange resin was α5
It became ~1 μm.

The obtained film forming agent was coated using a bar coater ($12).
It was applied to an aluminum panel that had been cleaned in advance, and dried and fixed at 230°C for 30 seconds.

Comparative Example A case where the epoxy ester paint used in Example 1 was applied as is (Comparative Example 1) and a thermosetting acrylic resin paint containing a commercially available wetting surfactant (solid content 18%)
(Comparative Example 2) was treated under the same coating and drying conditions as in the example.

Various tests were conducted on these Examples and Comparative Examples.

The results are listed in Table 1 below.

The initial wettability in the table indicates the state of wetness after 30 seconds had elapsed since the sample was immersed in deionized water and pulled out, and the case where the entire surface is slanted is taken as 100%.

Table 1 From these results, when using the resin paint of Comparative Example 2, die molding processability after film formation was good, but
It can be seen that the deterioration of hydrophilicity (in this case, expressed as water wettability) is small in the case of the present invention, and good results can be obtained.

Example 2 To the composition of Example 1, 8 g of a 5% solution of cobalt naphthenate was further added as a dryer, and the same kneading operation was performed to form an aluminum heat exchanger that had been previously degreased using a roll coater. The film was applied to a fin board, forced to dry, and then left indoors for 3 days to solidify the film.

Next, the same test as in Example 1 was conducted, and it was found that the same effects as those of Habo were obtained, and in particular, the durability against xylene was significantly improved, and the corrosion resistance was improved.

This seems to be because cobalt naphthenate acts as a catalyst.

Example 3 Finely powdered sulfonic acid type polystyrene cation exchange resin obtained by the method described in Example 1 [4-5 meq.
/(g -Dry -R month (Amber Light E R-12
0) Air-drying acrylic resin paint (manufactured by Dainippon Ink Co., Ltd.,
Acrydec A-165i' solid content 45%),
The exchange resin ratio was α70, and in order to improve the dispersibility of the ion exchange resin, a source side dispersant (manufactured by BM, West Germany, BM1) was used.
00O) was added in an amount of α5% based on the total weight of the resin paint, and after mixing, kneading was similarly performed in a bot mill for 5 hours.

The obtained film forming agent was coated to a thickness of 1. , the dry film thickness is α5μm for a transparent plastic plate of Omm (11
) and left to dry at room temperature to ensure fixation.

The temperature of the obtained painted surface was 40℃ and the relative humidity was 90±.
When an exposure test was conducted in a 5% atmosphere with an outside temperature of 27°C, the film on which the film of the present invention was formed remained transparent and did not become cloudy; There was cloudy weather all over the area.

Example 4 Weakly acidic cation exchange resin 10 [meq/(gl-Dr
y-R'lJ (manufactured by Rohm Sihars, Amberlite I
RC! -50) dry fine powder (average particle size LO μm, water content 5%) 250 g, modified alkyd resin paint (manufactured by Dainippon Ink Co., Ltd., P-786-50) 700 g,
*Shin L/N 300cc, dispersant (manufactured by West German BM, B
MlooO) 30 g.

Rough g of a leveling agent (BM1800A, manufactured by West German BM) was added and mixed for 30 minutes in a high speed stirrer. The solid content of the alkyd resin paint was 50%, and the exchange resin ratio of the obtained film forming agent was 0.038.

Apply this film-forming agent to a galvanized copper plate at The film was coated and heated to 200°C to form a film.

When the water wettability of the film was measured under the same conditions as in Example 1, a 1 test result of 97% was obtained after 48 hours, indicating that there was very little deterioration in hydrophilicity.

Patent applicant Nippon Light Metal Co., Ltd. Agent: Patent Attorney Keiji Matsunaga

Claims (1)

[Scope of Claims] 1. A hydrophilic film-forming agent obtained by dispersing ion-exchange resin powder in a resin coating consisting of coating film components and film-forming auxiliary elements. 2. The hydrophilic film forming agent according to claim 1, wherein the proportion of the ion exchange resin in the total amount of the coating film component and the ion exchange fat powder is α1 or more on a dry weight basis. .