KR101726583B1 - Coating agent for restoring car headlights - Google Patents

Abstract

The present invention relates to a coating agent which is for restoring car headlights and comprises a novel composition capable of forming a coating film which has excellent properties in terms of not only high strength and excellent scratch resistance, but also excellent light transmittance and surface gloss, and which can suppress a yellowing phenomenon, and thus can effectively restore a car headlight to a high quality. According to the present invention, the coating agent for restoring car headlights comprises, with respect to 100 parts by weight of the total composition: 40-60 parts by weight of an acrylate resin; 16-23 parts by weight of a curing agent; and 20-30 parts by weight of a solvent, wherein the acrylate resin is prepared through polymerization of a monomer mixture in the presence of a solvent with a polymerization initiator, the monomer mixture comprising styrene, 2-hydroxyethyl methacrylate, methyl methacrylate, and 2-methyl-2-propenoic 2-methylpropyl ester.

Description

{Coating agent for restoring car headlights}

The present invention relates to an automotive headlight restoration coating agent, and more particularly, to a new composition of automotive headlight restoration coating agent which forms a coating film having high scratch resistance, high transparency and yellowing resistance due to high strength.

Generally, a headlight of an automobile is composed of a lamp, a reflector, and a cover for protecting the lamp, and the cover is formed of plastic, and a hard coating layer is formed on the surface of the cover. The headlights of these vehicles must maintain a certain level of brightness for safe operation.

However, when the vehicle is driven for about three to five years, the brightness of the automobile headlight is considerably lowered. In some cases, the brightness of the automobile headlight deteriorates due to a problem in the headlight lamp. However, in many cases, This is because the hard coating layer on the surface of the light cover is peeled off and scratches are generated, thereby decreasing the light transmittance of the hardlight cover of the automobile.

When the brightness of the automotive headlight deteriorates due to a problem with the vehicle headlight cover, it is necessary to replace the cover of the automobile headlight. However, since it is impossible to replace only the headlight cover due to the structure of the headlight, The entire set should be replaced.

However, since replacing the entire headlight requires a lot of cost, there are many cases where the headlight is simply used without replacing the headlight due to the economic burden. However, even if the brightness of the headlight is decreased, it is extremely dangerous to operate without replacing it because there is a high possibility of an accident.

Meanwhile, a method for restoring the light transmittance of the automobile headlight cover has been proposed for this problem. The headlight is restored by polishing the surface of the headlight and coating the restoration agent.

However, conventional products used as restorers have disadvantages in that they can not form a coating layer having high strength, scratches are generated well, transparency is lowered and yellowing is also generated.

Korean Patent No. 10-0777478 (Nov. 12, 2007)

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a coating film having excellent physical properties such as high scratch resistance, light transmittance and gloss, , And to provide a new composition of automotive headlight restoration coating that can effectively restore automotive headlights to high quality.

According to one aspect of the present invention, there is provided a method for restoring the surface of an automobile headlight cover, which comprises 40 to 60 parts by weight of an acrylic resin, 16 to 23 parts by weight of a curing agent, and 20 to 30 parts by weight of a solvent, Wherein the acrylic resin is selected from the group consisting of styrene, 2-hydroxyethyl methacrylate, methyl methacrylate, 2-methyl-2-propenoic acid 2-methylpropyl ester 2-methyl-2-propenoic 2-methylpropyl ester) is polymerized in a solvent to prepare a headlight restoration coating agent for automobiles

According to another aspect of the present invention, there is provided a thermoplastic resin composition which comprises 100 parts by weight of the monomer mixture, 10 to 20 parts by weight of styrene, 1 to 20 parts by weight of 2-hydroxyethyl methacrylate, 50 to 70 parts by weight of methyl methacrylate and 1 to 10 parts by weight of 2-methyl-2-propenoic 2-methylpropyl ester.

According to another feature of the present invention, the solvent is selected from the group consisting of 4-methyl-2-pentanone, n-butyl acetate, propylene glycol monomethyl ether acetate, monomethyl ether acetate, solvent naphtha, xylene, 1,2,4-trimethylbenzene, ethylbenzene, butyl cellosolve, acetate) is used.

According to another aspect of the present invention, the polymerization initiator is tert-pentyl 2-ethylperoxyhexanoate.

The present invention having the above-described constitution can be applied to an inkjet recording ink comprising styrene, 2-hydroxyethyl methacrylate, methyl methacrylate, 2- methyl-2-propenoic acid 2-methyl (2-methyl-2-propenoic 2-methylpropyl ester) is used as the main component of the acrylic resin prepared by the polymerization reaction. Therefore, the acrylic resin having high strength and excellent scratch resistance But also a coating film which is excellent in transparency and gloss, excellent in light transmittance and is prevented from yellowing.

Therefore, when the automobile headlight is restored by using the restoration coating agent according to the present invention, a high quality coating film having excellent scratch resistance, transparency, gloss, and light transmittance and yellowing is formed on the surface of the headlight cover, And is restored to have excellent physical properties. This is the same effect as if you replaced a car headlight cover with a new one.

Hereinafter, the present invention will be described in more detail.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a restoration coating agent for restoring an automobile headlight, wherein the coating agent comprises an acrylic resin, a curing agent, a solvent and other additives.

The acrylic resin may be selected from the group consisting of styrene, 2-hydroxyethyl methacrylate, methyl methacrylate, 2-methyl-2-propene And 2-methylpropyl ester (methyl-2-propenoic acid 2-methylpropyl ester) in a solvent.

The styrene is contained in an amount of 10 to 20 parts by weight based on 100 parts by weight of the monomer mixture. When the content of styrene is less than 10 parts by weight, the gloss of the coating film due to the restoration coating agent is lowered. When the amount of the styrene is more than 20 parts by weight, the glossiness of the coating film is improved.

And, 2-hydroxyethyl methacrylate is contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the monomer mixture. When 2-hydroxyethyl methacrylate is contained in an amount of less than 1 part by weight, the adhesion of the restoration coating agent to be produced is deteriorated, and the strength of the coating film due to the restoration coating agent is lowered, If it is contained in an amount exceeding 20 parts by weight, the strength of the coating film due to the restoration coating agent is increased to improve scratch resistance, but the weatherability of the coating film is lowered.

Methyl methacrylate is contained in an amount of 50 to 70 parts by weight per 100 parts by weight of the monomer mixture. When methyl methacrylate is contained in an amount less than 50 parts by weight, scratch resistance of the coating film by the restorative coating agent is deteriorated. When the amount of methyl methacrylate is more than 70 parts by weight, adhesion of the coating film by the restorative coating agent is remarkably deteriorated It is not preferable.

Also, 2-methyl-2-propenoic acid 2-methylpropyl ester is contained in an amount of 1 to 10 parts by weight based on 100 parts by weight of the whole monomers. When the content of 2-methyl-2-propenoic acid 2-methylpropyl ester is less than 1 part by weight, the crosslinking density of the coating film due to the restorative coating agent is lowered and the acid resistance is lowered If it exceeds 10 parts by weight, the water resistance of the coating film due to the restoration coating agent is lowered, which is not preferable.

On the other hand, as the polymerization initiator, tert-pentyl-2-ethylperoxyhexanoate is used. In order to prevent the yellowing of the coating film, the amount of such a polymerization initiator is preferably minimized. It is preferable that 1 to 10 parts by weight of the polymerization initiator is used based on 100 parts by weight of the monomer mixture in consideration of physical properties of the coating film by the restoration coating agent.

The acrylic resin used in the present invention is prepared by polymerizing a monomer mixture as described above with the polymerization initiator in a solvent. Examples of the solvent include 4-methyl-2-pentanone, n-butyl acetate, propylene glycol monomethyl ether acetate, Solvent naphtha at least one of naphtha, xylene, 1,2,4-trimethylbenzene, ethylbenzene, and butyl cellosolve acetate is used. do.

Preferably, a solvent is first prepared, the monomer mixture is added to a solvent, a polymerization initiator is added, and polymerization is carried out by solution polymerization at about 80 to 180 ° C.

The restoration coating agent according to the present invention is prepared by adding a curing agent, a solvent and other additives to the acrylic resin prepared as described above. Preferably, 40 to 60 parts by weight of an acrylic resin, 100 parts by weight of a curing agent 16 To 23 parts by weight of a solvent and 20 to 30 parts by weight of a solvent, and a small amount of other additives are added.

As the hardener, known block isocyanate is used, and 16 to 23 parts by weight are used for 100 parts by weight of the whole restorative coating agent. When the hardener is added in an amount of less than 16 parts by weight, the hardening density of the coating film due to the restoration coating agent is lowered and the acid resistance of the coating film is lowered. If the hardener is added in an amount exceeding 23 parts by weight, the hardness of the coating film due to the restoration coating agent is lowered.

 Examples of the solvent include xylene, toluene, ethyl acetate, propylene glycol monomethyl ether acetate, 4-methyl-2-pentanone pentanone, and n-butyl acetate.

These solvents are added in an amount of 20 to 30 parts by weight based on 100 parts by weight of the restoration coating agent. If the amount is less than 20 parts by weight, the coating property of the restoration coating agent deteriorates and pinholes are liable to be generated in the coating film. The solids content of the restoration coating agent is lowered, and the appearance and quality of the coating film are deteriorated.

As other additives, ordinary additives such as a smoothing agent, a slip agent, a light stabilizer, an antioxidant and the like for improving physical properties of a coating film are added in a small amount in a usual range of use.

Since the restorative coating agent of the present invention having the above composition mainly uses an acrylic resin synthesized from the monomer mixture as described above, the crosslinking density of the coating film is improved and the coating film properties are excellent, , Weatherability, as well as high strength of the coating film, excellent scratch resistance, good gloss, and excellent transparency and light transmittance. It also has the advantage of preventing yellowing.

Therefore, when the automobile headlight is restored with the restoration coating agent according to the present invention, a high quality coating film having excellent adhesion to automobile headlights, excellent scratch resistance, glossiness, transparency and light transmittance, The same effect as that of replacing the headlight with a new one can be obtained.

A method of restoring an automobile headlight using a restorative coating agent having such a composition will be described below.

First, attach a protective cover and masking tape around the car headlight cover itself. These protective covers and masking tapes are intended to prevent the car body from being damaged during the polishing process described later or to prevent the coating material from being buried in the car body during the coating process.

Subsequently, the surface of the automobile headlight cover is sanded and polished. Preferably, the sandpaper is first sandwiched with 300 sandpaper, followed by 400 sandpaper, followed by 600 sandpaper to form a third sandpaper, followed by 1000 sandpaper to form a fourth sandpaper, finally sanding to 1300 sandpaper, do. As described above, sandpaper having various roughnesses is used to sand the surface of the headlight cover by sanding it in multiple steps, thereby effectively removing foreign matter from the surface of the headlight cover and improving the smoothness of the surface of the headlight cover.

After the sandpaper is finished, the surface of the headlight cover of automobile is wiped off with a degreasing agent, degreased, washed with water and then dried.

And coating the restoration coating agent as described above. The restorative coating is sprayed onto the surface of the vehicle headlight cover, preferably the restorative coating is sprayed twice at intervals of about two or three minutes and dried. Then, remove the protective cover and masking tape to finish the operation.

Example

17 parts by weight of styrene, 18 parts by weight of 2-hydroxyethyl methacrylate, 58 parts by weight of methyl methacrylate, and 70 parts by weight of 2-methyl-2-propenoic acid 2-methylpropyl ester was added to a mixture of xylene The temperature is maintained by raising the temperature to about 140 ° C. Then, 8 parts by weight of tert-pentyl 2-ethylperoxyhexanoate as a polymerization initiator was added dropwise over a period of several tens of minutes and the mixture was reacted for about 2 hours to prepare an acrylic resin .

A transparent restorative coating agent was prepared by mixing 55 parts by weight of the acrylic resin, 16 parts by weight of the curing agent, 24 parts by weight of the solvent, 0.5 part by weight of the smoothing agent, 2 parts by weight of the slip, 2 parts by weight of the light stabilizer, and 0.5 part by weight of the antioxidant .

The coating agent thus prepared was coated on a cover of an automobile headlight by the method as described above, and physical properties of the coating layer were tested.

As can be seen from Table 1, the coating agent according to the present invention is not only excellent in glossiness and adhesiveness but also excellent in weatherability and resistance to slipping. Also, no yellowing occurred.

Item

Polish
Weatherability
(2000 hours)
My scratch

Attachment
Abrasion resistance
(Wear rate (g / 1000 times))
Yellow
93.8 DEG
0.16

Good

100/100
1.0

0

* Gloss: KS M 5000-3312 60 ㅀ specular gloss of paint. Take the average value measured five times according to the test method.

* Weatherability: Weatherability: Comparison of film condition after 2000 hours using QUV apparatus manufactured by Q-Panel

* Scratch resistance: measured 20 times after 20 round trips with ANTEK car washer equipment.

* Adhesion: Cross cut 100/100 (2mm) No peeling, No crack

* Abrasion resistance test: Measurement of abrasion around 1000 times under conditions of 1000g load, H-22 of abrasive wheel, and 60rpm of revolution using a TABER type tester.

* Sulfur denaturation: After normal painting and drying, check the color discoloration after drying at 150 ℃ for 1 hour.

Claims (4)

For restoring the surface of an automobile headlight cover,
40 to 60 parts by weight of an acrylic resin, 16 to 23 parts by weight of a curing agent and 20 to 30 parts by weight of a solvent,
The acrylic resin may be selected from the group consisting of styrene, 2-hydroxyethyl methacrylate, methyl methacrylate, 2-methyl-2-propenoic acid 2-methylpropyl ester (2- methyl-2-propenoic 2-methylpropyl ester) is polymerized with a polymerization initiator in a solvent,
The monomer mixture contains, per 100 parts by weight,
10 to 20 parts by weight of styrene,
1 to 20 parts by weight of 2-hydroxyethyl methacrylate,
50 to 70 parts by weight of methyl methacrylate, and
1 to 10 parts by weight of 2-methyl-2-propenoic 2-methylpropyl ester.
delete The method of claim 1, wherein
The solvent is selected from the group consisting of 4-methyl-2-pentanone, n-butyl acetate, propylene glycol monomethyl ether acetate, at least one of naphtha, xylene, 1,2,4-trimethylbenzene, ethylbenzene, and butyl cellosolve acetate is used. Wherein the restoration coating agent for automotive headlights is characterized in that
The method according to claim 1,
Characterized in that the polymerization initiator is tert-pentyl 2-ethylperoxyhexanoate.