KR100388895B1 - Process for producing High Corrosion, Anti-Finger Printer Resin having excellent Formability and Anti-corrosion - Google Patents

Abstract

An object of the present invention is to provide a method for producing a fingerprint-finishing coating for producing a fingerprint-treated resin coated steel sheet excellent in workability and corrosion resistance of a fingerprint-treated steel sheet used in home appliances. 2 to 40% by weight based on the ethylenically unsaturated monomer capable of radical polymerization and the polymerization initiator can be polymerized in the gas phase to the urethane-modified acrylic copolymer synthesized using 0.1 to 5% by weight based on the radically polymerizable ethylenic monomer. In order to improve the corrosion resistance and processability of the resin solution prepared in the form of a cold brand in which an acrylic modified urethane resin is added in an amount of 10% by weight or less to a resin obtained by dispersing an acrylic ethylene copolymer having an average molecular weight of 7,000 to 15,000 in water. 4-15 weight%, 10-20 weight% of silica, and 2-10 weight% of ethanol or isopropyl alcohol are prepared into the method of manufacturing the anti-fingerprint coating.

Description

Process for producing High Corrosion Resistance Anti-fingerprint Composition Solution excellent in processability and corrosion resistance {Process for producing High Corrosion, Anti-Finger Printer Resin having excellent Formability and Anti-corrosion}

The present invention relates to a method for preparing a fingerprint resin composition solution having excellent workability and corrosion resistance by applying a resin composition to a galvanized steel sheet.

The resin composition is mainly coated on the phosphate-treated galvanized steel sheet to about 1 micrometer (μm) to form a thin film to the surface treatment to have fingerprint resistance, corrosion resistance, excellent workability, to have excellent fingerprint resistance, processability, corrosion resistance described above As it is mainly intended for use in electronic products such as home appliances or computer cases.

The anti-finger steel sheet referred to herein is a steel plate applied to indoor electronic products such as home appliances or computer cases by applying anti-fingerprint resin as a thin film to a phosphate-treated galvanized steel sheet. Electroplated galvanized steel sheet with phosphate coating is hard to be erased in post process if hand fingerprints are left while working, and indoor electronic products are frequently touched by hand. Easy to be Therefore, the anti-finger steel sheet is produced by the resin coating treatment.

Conventionally, anti-fingerprint resin liquid and lubricated steel sheet resin liquid are commercially marketed separately, and the number of assembly parts undergoing extreme processing is increasing during the manufacturing process of consumers. At the same time, there was no coating solution in consideration of blackening or corrosion resistance of the processed portion.

In general, acrylic resins used as anti-fingerprint resins are effective in solvent resistance, alkali resistance, gloss, weather resistance, economic efficiency, and anti-fingerprint resistance, but the resin itself has a high hardness, which makes it difficult to stretch the resin during processing and is also vulnerable to corrosion resistance. It has a quality defect.

In particular, in recent years, the invention of the anti-fingerprint resin solution which satisfies the corrosion resistance and workability to the new paint which can ensure the physical property of an anti-fingerprint steel plate and a lubrication steel sheet at the same time is needed. The physical properties of the anti-fingerprint steel sheet and the lubricated steel sheet are similar to each other, but have properties opposite to each other in lubricity, glossiness, and corrosion resistance.

Therefore, in order to satisfy such a defect, it was found that by adding a small amount of urethane resin which can improve processability and corrosion resistance to the acrylic resin, processability and corrosion resistance can be improved at the same time.

In addition, silica improves the corrosion resistance of the resin, and its mechanism makes it difficult to penetrate the corrosion factors by filling a lot of fine pores between the resin particles and filling these fine pores. Accordingly, the present invention is to provide an anti-fingerprint resin composition having excellent processability and corrosion resistance according to the addition of an appropriate amount of urethane resin, the type and concentration ratio of silica to be added, and the particle size.

The present invention is basically prepared in the form of a cold blend by adding an acrylic modified urethane resin to 10% by weight or less to the resin in which the acrylic polymer having a number average molecular weight of 7,000 to 15,000 polymerized in the gas phase is dispersed in water. It consists of an anti-fingerprint composition.

The present invention also adds 4 to 15% by weight of polypropylene wax, 10 to 20% by weight of silica, and 2 to 10% by weight of ethanol or isopropyl alcohol in order to improve processability, corrosion resistance, wetting and the like to the resin composition. It consists of an anti-fingerprint, that is, an anti-fingerprint composition.

Urethane resins have excellent properties in elongation and adhesion, but have poor physical properties in weatherability and alkalinity, and are expensive compared to other resins. Therefore, when acrylic resins and urethane resins are mixed in an appropriate ratio, the above high lubrication And it was devised that the corrosion resistance can be secured. In addition, polypropylene wax and silica are added to improve processability and corrosion resistance.

The paint compositions that make up the resin are largely classified into Part A (resin) and Part B (curing agent), which are Part A, and additives include polypropylene wax, silica, and a web which improves the flowability of a solution. Ting agents can be mentioned.

The curing agents applicable to this resin include various curing agents such as epoxy, melamine resin, aziridine series, carbodiimide, etc. However, it is preferable to use a small molecular weight in order to give many reactors at the same content. It is preferable that the baking temperature is high because the reaction is performed at, and the reaction temperature is preferably 150 ° C. or higher.

In addition, melamine resins must use acid catalyst to increase the low temperature reactivity, so that the curing reaction is good even at low baking temperature. For example, in melamine system, it is preferable to use cymel325 which has good room temperature reactivity. Because it has a characteristic of reacting at, it has a drying characteristic that can be reacted when the reaction temperature is high or the reaction time is long.

In addition, as a curing agent that can react at room temperature and low temperature, there are aziridine-based and carbodiimide-based, among which the aziridine-based structure has a trifunctional group rather than a monofunctional group. In other words, since it has three aziridine reactors per molecule, even if a small amount of hardener is added, it is more advantageous in terms of physical properties since three subjects are combined in one molecule.

In the case of aziridine curing agent, it should be applied as a two-part type (PartA and PartB are separated and mixed just before use), because the molecular ring of aziridine is opened and hydrolyzed under acidic and basic conditions. In the case of mixing with the main resin, it is preferable to use within 1 to 2 days.

In addition, the aziridine system should be used with caution because it is toxic, and even if a small amount of the aziridine system is used, the amount of the aziridine must be limited, and if it is not mixed, the aziridine may be used for reuse. It can be replenished and used as much as the initial dose.

Therefore, in order to solve these problems, the present patent uses high molecular weights to increase the molecular weight of urethane-modified acrylic resin to represent all the properties of the anti-fingerprint coating without curing reaction, and when the higher curing degree is required, the curing agents listed above may be used. There is a number. The curing mechanism of the curing agents proceeds to a mechanism that reacts with the oxygen of the carboxyl group by attacking the hydrogen of the carboxyl group of the Part A resin.

Next, the additives added to the above-described paint composition will be described.

Silica improves the corrosion resistance of the resin, and its mechanism makes it possible to have many fine pores between the resin particles and fill these fine pores, thereby making it difficult to penetrate corrosion factors.

The silica used in the present invention can be used in various ways, such as hemosilica or colloidal silica dispersed in water, but in the case of hemosilica, it is ground as a three-stage mill for mixing with the resin to facilitate mixing with the resin. It is recommended that this is limited by the solid content and viscosity of the resin has been recently used ball mill dispersion method.

In addition, the particle size of silica is important. In the present patent, two kinds of silica, 10 nm and 20 nm, are used for the silica particles. The reason for the difference in the size of silica particles is that the 20 nm silica particles do not fill the space of each other enough, and the small particles fill the space filled with the large particles, so that the silica is completely concentrated in the resin layer. This is because the increase of.

On the other hand, the addition amount of silica is good 10 ~ 20% by weight, corrosion resistance is less than 10% by weight, if more than 20% by weight does not affect the corrosion resistance effect, but gloss and workability is reduced.

Waxes are used for improving lubricity, and generally used waxes include canoe-based waxes, polyethylene waxes, polypropylene waxes, and teflon waxes. In terms of physical properties, Teflon waxes are preferable. It is difficult to control the particle size, and the use of it is avoided because of poor stability such as floating and sedimentation in the liquid phase and high price.

Therefore, polyethylene and polypropylene are widely used as waxes. This is because the price is cheaper than other waxes, and even if a small amount is added to the paint composition, the lubricity can be improved. Among the two waxes, it is more preferable to use polypropylene wax having a high melting point.

In addition, even the same polypropylene wax has different lubricity depending on the melting point of the wax. The higher the melting point of the wax, the harder it remains on the coating film. On the contrary, when the melting point is low, on the contrary, during continuous pressing, the resin received from the processing surface softens with increasing temperature of the processing surface, and the wax having low melting point is converted into a liquid state. The main cause of this inhibition, ie, it should be explained as being converted into a viscous state.

In addition, the particle size of the wax has a great influence on the quality, but when the wax particle size is coarse, the frictional force at the surface is reduced by protruding to the upper portion of the anti-fingerprint resin coating of the present invention, which is applied as a thin film. When passing through the coating film, there is no wax in the resin, and thus the wax does not fully exhibit its function.

Therefore, the particle size of the wax contained in the anti-fingerprint coating is less than 0.1 micrometer and the quality is good, and the wax having such particles penetrates evenly in the resin layer and is evenly dispersed in the resin layer, the intermediate layer, and the lower layer to fully exhibit the main functions of the wax. Should be

The amount of wax can be added 4 ~ 15% by weight. If the amount of wax to be added to the paint composition is less than 4% by weight, it is difficult to secure sufficient slip property due to too little wax in the to-fin coating film. On the contrary, if the amount is more than 15% by weight, there is no improvement in lubricity due to the increase in the amount of wax. Rather, it is not preferable because the wax component is increased to deteriorate the corrosion resistance and solvent resistance and the glossiness of the coating film is lowered.

Wetting agent or wetting agent is for improving lubricity and smoothness, and it is preferable to use an alcohol-based solvent having affinity with water in order to improve quick-drying and applicability of the aqueous liquid. Most preferably, n-Butanol is the best but it is not good at the time of application because it generates a lot of smell.

In the present invention, the anti-fingerprint solution has a function of improving the wettability of the solution when the steel sheet is applied to the resin, and when baking the baking, the volatility is good even at low temperature, so that the coating film does not remain in the dried film after drying. Therefore, in the present invention, it is preferable to use a solvent having a low molecular weight methanol, ethanol and isopropyl alcohol system. In addition, the amount to be added is preferably 2 to 10% by weight, more preferably 3 to 5% by weight based on the total amount of paint.

(Example 1)

In order to demonstrate this invention more concretely and in detail, an Example is given and described below.

Table 1 shows an example of the basic composition of the cold blend resin solution as an embodiment of the present invention. The resin composition according to the present invention is basically a resin obtained by dispersing an acrylethylene copolymer having a number average of 7,000 to 15,000 polymerized in the gas phase in water as described above (in Table 1, AC-580 and AC-5120 manufactured by ELID Signal) Optionally use either of acrylic modified polyurenetan resin to 10% by weight or less, and lymethanolamine to 1% by weight or less to add polypropylene wax to improve lubricity, corrosion resistance and processability. 4 to 15% by weight, 10 to 20% by weight of silica, 2 to 10% by weight of ethanol or isopropyl alcohol are prepared. In this embodiment, as shown in Table 1, specimens A and B, C and D, Each of E and F is divided into four examples to determine the composition ratio of each copolymer resin, urethane resin, and the like, and a curing agent, wax, silica, and a wetting agent are added thereto and coated on a galvanized steel sheet. Surface treated.

The results are shown in Table 1.

As shown in Table 1, after adding a silica, wax, wetting agent, etc. to a resin liquid mixed with a copolymer resin and a urethane resin, and adding a hardened paint containing a carbodiimide as a curing agent on a phosphate-treated galvanized steel sheet, reaching plate temperature The plate was dried to 80 ° C. to prepare a steel plate, and the film thickness was adjusted to 1 micrometer.

As physical properties, anti-fingerprint, appearance, alkali resistance, solvent resistance, tentacle fingerprint resistance, and corrosion resistance were evaluated according to the following criteria and the contents thereof are listed in Table 2. Appearance was evaluated using the color difference meter.

(Fingerprint resistance)

Anti-fingerprint was divided into the indexes listed below by pressing the human fingerprint on the steel sheet manufactured according to the above method for 3 seconds and the accuracy of the fingerprint with the naked eye. In order to use anti-fingerprint in actual product manufacturing and production, a score of 3 or more is required.

No fingerprint traces at all: Rating 5

Almost unknown fingerprint trace: Rating 4

If you look closely you can see fingerprint traces: Rating 3

Fingerprint traces appear: Rating 2

Fingerprint traces are well seen.

(Processability and scratchability)

Processability and scratchability were marked according to the coin trace when scratched with a coin, and the traces of coin marks were divided into the indicators listed below. In order to actually use the processability, the score should be 3 or higher.

I can't tell any scratches with a coin

Almost no evidence of coin scratches: rating 4

If you look closely you can see the scratches with a coin: Rating 3

Marking Scratches with Coins: Rating 2

Good at scratching with a coin: Rating 1

(Alkali resistance)

After preparing a steel sheet based on the above standards, the state of the coating film after immersion for 10 minutes in a 50% aqueous solution of 50% caustic soda was visually observed. In fact, in order to use alkali resistance in practice, the score must be 3 or more points.

Discoloration is unknown at all: Rating 5

Almost no discoloration: rating 4

Discoloration can be seen by careful observation: Rating 3

Discoloration and peeling traces appear: Rating 2

Discoloration and peeling traces can be seen well: Rated1

(Solvent resistance)

After the steel sheet was manufactured based on the above standards, the state of the coating film after reciprocating 10 times by applying a constant force to the gauze was applied to the gauze and visually observed. In fact, in order to have good contentability, the score should be at least 3 points.

Discoloration traces are unknown at all: Rating 5

Almost no color change trace: Rating 4

Discoloration traces when observed well: Rating 3

Discoloration is visible: Rating 2

Discoloration is clearly visible: Rating 1

Tentacles Fingerprint

The method of evaluating the tentacle fingerprint resistance is primarily to measure the glossiness of a high lubricated steel sheet, and then apply petroleum jelly to the same steel sheet again to remove residual petrolatum on the steel sheet. By measuring the glossiness again, it can be evaluated by calculating the difference in glossiness before and after the glossiness measurement. At this time, if there is a large difference in glossiness, the tentacle fingerprint resistance is poor. On the contrary, a small difference means that the tentacle fingerprint is good. In fact, in order to have a good tentacle fingerprint resistance, the score should be 3 or higher.

Glossiness difference before and after petroleum jelly is less than 2: Rating 5

Glossiness difference before and after petroleum jelly is 2 ~ 4: Rating 4

Glossiness difference before and after petroleum jelly is 4 ~ 6: Rating 3

Glossiness difference before and after petroleum jelly is 6-8: Rated 2

Glossiness difference before and after petroleum jelly is more than 8: Rating 1

Corrosion resistance was evaluated according to the ZIS method, and after 168 hours, the area of rust was evaluated.

No rust: Rating 5

Rust less than 5%: Rating 4

Rust rate 5 ~ 30%: Rating 3

Rust 50 ~ 50%: Rating 2

Rust over 50%: Rating 1

The coating composition prepared according to the above example was coated on a galvanized steel sheet and subjected to surface treatment. Then, the rubbing resistance, scratch resistance, and corrosion resistance of the final product were examined, and the results are shown in Table 2.

As can be seen from the above examples, the fingerprinting properties of the products of the present invention were found to be extremely good. In addition, the surface lubrication activity such as scratch resistance was also good, it can be seen that the corrosion resistance is also very good. In addition, strong resistance to external chemical preparations such as solvent resistance and alkali resistance was confirmed.

As described above, according to the present invention, in particular, it is possible to supply a surface-treated steel sheet having anti-fingerprint properties and excellent workability and corrosion resistance.

Claims (2)

Polypropylene to a resin liquid prepared in the form of a cold blend in which an acrylic modified urethane resin was added to 10% by weight or less of a resin in which an acrylic ethylene copolymer having a number average molecular weight of 7,000 to 15,000 polymerized in a gas phase was dispersed in water. Method of producing a fingerprint resin composition solution, characterized in that 4 to 15% by weight of wax, 10 to 20% by weight of silica, 2 to 10% by weight of ethanol or isopropyl alcohol as a wetting agent is added to the amount of the conductive material. . The method of claim 1, wherein the resin composition is dried on a phosphate-treated galvanized steel sheet so as to reach a temperature of 80 ° C. after the coating, and the coating thickness thereof is adjusted to be about 1 μm to produce a surface-treated steel sheet. The manufacturing method of the anti-fingerprint composition solution made into.