KR101878497B1 - Epoxy Coating Composition for Weather Area of Ship - Google Patents

Abstract

The present invention relates to a two-component epoxy coating composition which can be applied to an exposed portion of a ship, and which contains bisphenol-A epoxy resin as a main component and has a glass transition temperature (Tg) of 10 to 20 ° C, -KOH / g) and acrylic acid resin.

Description

[0001] Epoxy Coating Composition for Weather Area of Ship [

The present invention relates to a composition of a liquid epoxy paint which can be applied to an exposed area of a ship, for example, an area exposed to the external climate without any protective equipment such as an exposed deck.

Two-part curing systems such as a main (epoxy) / curing agent (amine, amide) are widely known as room temperature curing systems generally applied to paints.

The coating film formed by the curing of the epoxy resin forms a dense coating film structure having a macromolecular weight by a cross-linking reaction, which has a high resistance to a solvent, has good barrier properties against external substances such as moisture and gas, Long-term durability is assured compared to a paint employing a resin.

Epoxy resins have useful properties that can be cured at room temperature, and their physical properties can be easily obtained at room temperature, which is widely used in the field of heavy-duty paints. As the curing agent used for curing the epoxy resin at room temperature, amines, amine derivatives or polyamide resins having active hydrogen are mainly used.

However, in the case of epoxy resin, when hetero atoms (N, O, etc.) are directly bonded to the aromatic ring, ultraviolet rays of 280 nm or more are absorbed and photolyzed to generate free radicals and oxidative decomposition. As a result, yellowing, chalking, There is a disadvantage in that this occurs.

When an epoxy paint is used as an outer top coat for ships, polyamide is generally used as a curing agent in an epoxy resin. However, when polyamide is used, it has a long pot life and has excellent adhesion , The viscosity is high, the curing property at a low temperature of 10 占 폚 or less drops sharply, the compatibility with the epoxy resin is inferior, and the low temperature drying is poor, which may cause problems such as blushing.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and one aspect of the present invention is to provide an epoxy coating composition which is applied to an external weathering portion of a ship having excellent weatherability and workability (low-temperature drying and blushing property) The purpose.

An epoxy coating composition for a ship-exposed area according to an aspect of the present invention comprises:

A two-component epoxy coating composition comprising a mixture of a base and a curing agent,

The subject matter includes a bisphenol-A epoxy resin,

Wherein the curing agent comprises an acrylic acid resin having a glass transition temperature (Tg) of 10 to 20 占 폚.

At this time, the acrylic acid resin may be at least two or more selected from the group consisting of dimethylaminoethyl methacrylate, ethyl hexyl acrylate, acrylic acid and styrene monomer. Characterized in that the monomers are composed of a polymerized resin.

Also, the acrylic acid resin essentially includes ethyl hexyl acrylate and styrene monomer.

The acrylic acid resin has an acid value and an amine value of 32 mg-KOH / g to 37 mg-KOH / g.

The acrylic acid resin may be a copolymer of 8 to 13% by weight of dimethylaminoethyl methacrylate, 25 to 35% by weight of ethyl hexyl acrylate, 2 to 5% by weight of acrylic acid, And 44 to 57% by weight of a styrene monomer.

At this time, the subject further comprises a pigment, a first solvent, and a second solvent.

In this case, the curing agent may further include the first solvent, and the curing agent may include 75 wt% to 85 wt% of acrylic acid resin and 10 wt% to 20 wt% of the first solvent.

In addition, it is preferable that the subject and the curing agent are mixed at a mixing ratio of 100: 60 to 100: 70 (weight ratio).

Further, the epoxy coating composition is characterized in that it forms a coating film having a thickness of 75 to 125 탆 and is used in an external exposure area of a ship.

The epoxy coating composition according to the present invention improves the conventional epoxy-polyamide curing structure and adopts an epoxy-acrylic acid curing structure system to stabilize physical properties, thereby minimizing the occurrence of choking occurrence, thereby maintaining the appearance and performance of the coating film surface. As a result, it has an excellent effect of weatherability and workability (low-temperature drying and blushing property) when it is used in an exposed area of a ship.

Before describing the present invention in detail, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention, which is defined solely by the appended claims. shall. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise stated.

Throughout the description and claims, unless the context requires otherwise, the word "comprise" is intended to include the stated article, step or group of articles, and steps; It is not meant to exclude an object, step or group of objects or a group of steps.

On the contrary, the various embodiments of the present invention can be combined with any other embodiments as long as there is no clear counterpoint. In particular, any feature that is indicated to be advantageous or advantageous may be combined with any other feature or feature that is indicated to be advantageous or advantageous.

An epoxy coating composition according to an embodiment of the present invention includes a base and a curing agent.

subject

The subject of the epoxy coating composition used in this embodiment includes an epoxy resin, a pigment, and a solvent.

1. Epoxy resin

The epoxy resin is a diglycidyl ether (DGEBA) of bisphenol-A produced by reacting diphenyl called bisphenol-A with epichlorohydrin and has a viscosity of 11,000 to 14,000 (CPS) at 25 ° C. and has an epoxy equivalent (EEW ) 184 to 194 are used.

The structural formula of the epoxy resin is shown in Chemical Formula (1).

2. Pigment

Titanium dioxide (TIO2), ferric oxide, and copper phthalocyanine are used as pigments for coloring epoxy paints. Talc (TALC) and silica can be used for physical properties such as volume and flowability of paints. have.

3. First solvent

The solvent of the epoxy resin is not limited, but propylene glycol monomethyl ether acetate and MIBK (Methyl Iso Butyl Ketone) may be used.

4. Second solvent

The second solvent is used to improve the solubility of the first solvent and is not limited to the kind. For example, xylene, cocosol, and toluene may be used.

In this case, it is preferable that the subject contains 13 to 19% by weight of a bisphenol-A epoxy resin, 54 to 60% by weight of a pigment and 13 to 19% by weight of a solvent. When the epoxy resin is used in an amount of less than 13% by weight, the chemical resistance, rust resistance and abrasion resistance of the coating film are lowered. When the epoxy resin is used in an amount exceeding 19% by weight, there is a problem in appearance and workability of the coating film. When the pigment is used in an amount less than 54% by weight, there is a problem such as permeability of the coating film and adhering heat, and when the pigment is used in an amount exceeding 60% by weight, there is a problem of glossiness and anti- Is used in an amount of less than 13% by weight, there is a problem of lowering the solubility of the resin (polymer), and when it is used in an amount exceeding 19% by weight, there is a problem of uneconomical problems.

Hardener

The curing agent of the epoxy coating composition used in this embodiment includes an acrylic resin, and a third solvent.

1. Acrylic acid resin

The acrylic acid resin preferably has a glass transition temperature (Tg) of 10 to 20 占 폚. This is to improve adhesion by increasing the acid value appropriately.

The acrylic acid resin that can be used is a resin in which at least two or more monomers selected from the group consisting of dimethylaminoethyl methacrylate (DMAEMA), ethyl hexyl acrylate (EHA), acrylic acid (AA) and styrene monomer (SM)

At this time, the acrylic acid resin preferably contains ethyl hexyl acrylate and styrene monomer,

8 to 13% by weight of dimethylaminoethyl methacrylate, 25 to 35% by weight of ethyl hexyl acrylate, 2 to 5% by weight of acrylic acid, and 44 to 40% by weight of styrene monomer. By weight to 57% by weight.

When the amount of dimethylaminoethyl methacrylate is less than 8% by weight, there is a problem of poor drying of the paint. When the amount of dimethylaminoethyl methacrylate is more than 13% by weight, And bending property. When the content is more than 35% by weight, there is a problem of hardness.

If the amount of the styrene monomer is less than 44% by weight, problems such as gloss and hardness may occur. If the amount of the styrene monomer is less than 45% by weight, There is a problem of weatherability such as yellowing.

The physical properties of the acrylic acid resin which can be preferably used as the above-mentioned acrylic acid resin are shown in Table 1 below.

Item Acrylic acid resin Tg (占 폚) 10-20 Acid value (mg-KOH / g) 32 to 37 Amine value (mg-KOH / g) 32 to 37 Solid content (%) 65 ± 5 Viscosity (Gardner) Z ~ Z6 Color difference (ΔE) MAX.2

2. Solvent

In the curing agent, the first solvent and the second solvent used in the subject are used, but the second solvent may or may not be used.

The acrylic acid resin in the curing agent is 85 wt% to 95 wt%, and the solvent includes 5 wt% to 15 wt% of the sum of the first solvent and the second solvent.

In addition, the epoxy coating composition used in this embodiment includes a dispersing agent which efficiently disperses the pigment uniformly and stably in the resin, an anti-settling agent which prevents the pigment from depositing on the bottom of the container during storage of the paint, An antifoaming agent for preventing the occurrence of the corrosion, and the like.

At this time, it is preferable that the above-mentioned subject and the curing agent are mixed at a ratio of 100: 60 to 100: 70 (weight ratio) for stable physical properties such as dryness and curability considered in designing the coating.

When the curing agent is mixed at less than 60 parts with respect to 100 parts by weight of the subject, there is a problem such as weather resistance and gloss reduction of the coating film. When the curing agent is more than 70 parts, there is a problem in that the curing agent is mixed with the anti- There is a problem.

Example

Example 1

200 g of bisphenol-A epoxy resin, 700 g of titanium dioxide (TIO2), 90 g of propylene glycol monomethyl ether acetate as a first solvent and 100 g of xylene as a second solvent and 10 g of dimethylaminoethyl methacrylate (DMAEMA) 600 g of an acrylic acid resin polymerized with 10% by weight of acrylic acid, 30% by weight of ethylhexyl acrylate, 5% by weight of acrylic acid and 55% by weight of styrene monomer, An epoxy coating composition was prepared using a curing agent comprising 110 g of propyleneglycol monomethyl ether acetate.

Example 2

200 g of bisphenol-A epoxy resin, 700 g of titanium dioxide (TIO2), 90 g of propylene glycol monomethyl ether acetate as a first solvent and 100 g of xylene as a second solvent, and dimethylaminoethyl methacrylate 620 g of an acrylic acid resin polymerized with 10% by weight of dimethylaminoethyl methacrylate, 30% by weight of ethyl hexyl acrylate, 3% by weight of acrylic acid and 57% by weight of styrene monomer, An epoxy coating composition was prepared using a curing agent comprising 110 g of propylene glycol monomethyl ether acetate as a solvent.

Comparative Example 1

Except that 610 g of acrylic acid resin polymerized with 7% by weight DMAEMA (dimethylaminoethyl methacrylate), 20% by weight of EHA (Ethyl hexyl acrylate), 6% by weight of AA (Acrylic acid) and 67% by weight of Styrene monomer An epoxy coating composition was prepared in the same manner as in Example 1.

Comparative Example 2

Except that 590 g of an acrylic acid resin polymerized with 15% by weight of DMAEMA (dimethylaminoethyl methacrylate), 20% by weight of EHA (Ethyl hexyl acrylate), 8% by weight of AA (Acrylic acid) and 57% by weight of SM (Styrene monomer) 1, an epoxy coating composition was prepared.

Comparative Example 3

Except that 620 g of an acrylic acid resin polymerized with 10% by weight of DMAEMA (dimethylaminoethyl methacrylate), 25% by weight of EHA (Ethyl hexyl acrylate), 7% by weight of AA (Acrylic acid) and 58% by weight of SM An epoxy coating composition was prepared in the same manner as in Example 1.

The compositions of the above-described Examples and Comparative Examples are summarized in Table 2.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 subject Epoxy resin BPA Epoxy 200 g Pigment Titanium dioxide (TIO2) 700 g The first solvent Propylene glycol monomethyl ether 90 g The second solvent Xylene 100g Hardener
Acrylic acid resin DMAEMA 10 wt%, EHA 30 wt%, AA 5 wt%, and SM 55 wt% 600 g DMAEMA 10% by weight, EHA 30% by weight, AA 3% by weight and SM 57% by weight 620 g DMAEMA 7 wt%, EHA 20 wt%, AA 6 wt%, and SM 67 wt% 610 g DMAEMA 15 wt%, EHA 20 wt%, AA 8 wt%, and SM 57 wt% 590 g DMAEMA 10 wt%, EHA 25 wt%, AA 7 wt%, and SM 58 wt% 620 g The first solvent
Propylene glycol monomethyl ether
110g

Experimental Example

As described in the above-mentioned Examples and Comparative Examples, a 100 탆 coating film was formed by mixing the subject of a coating material with a curing agent (subject: hardener = 1: 1 (volume)) by air spraying method, And the weathering resistance were tested and summarized as shown in Table 3.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Low-temperature drying ◎ ○ X △ △ Blushing ○ △ △ X X Weatherability ○ △ △ △ △

(Legend: ◎ Excellent, ○ Excellent, △ Normal, ⅹ Bad)

The test methods used at this time are listed in Table 4.

division Test Methods Related grounds Weatherability QUV 1. UV irradiation / condensation cycle in UV-B Lamp (280nm ~ 315nm)
60 ℃, UV 8 hours ⇔ 40 ℃, Dark Condensation 4 hours
2. Evaluation Items: DE, GLOSS ASTM G154 WOM 1. Xenon light exposure 102 minutes ⇔ Xenon light exposure and water spray 18 minutes
Chamber conditions: 63 ± 5 ° C, pH 6.0 to 8.0
2. Evaluation Items: DE, GLOSS ASTM G152 Color difference (DE)

L* = Lightness, a* = +Red/-Green, b* = +Yellow/-BlueMeasure color difference before and after test

L * = Lightness, a * = + Red / -Green, b * = + Yellow / -Blue ASTM D2244 Gloss (GLOSS) Gloss retention was measured by measuring the gloss before and after the test with the reflectance when the incident angle and the acceptance angle were 60 ° using a gloss meter. ASTM D523 BLUSHING Judging discoloration and appearance
- Evaluation: 10 <9 <8 <7 <6 <5 ... <2 <1
Good ← ------------------------ → Bad Self-judgment 10: Discoloration and Appearance No abnormality
9 ~ 8: Fine discoloration and appearance change (no problem at the time of visual determination)
7 ~ 6: BLUSHING occurrence and appearance change (BLUSHING occurrence small to medium)
5 ~ 0: Occurrence of BLUSHING and appearance change (large occurrence of BLUSHING) Low temperature
Drying
Dry touch 10mil on the glass plate Draw down and measure the time that the paint does not get on the surface of the finger when it is lightly contacted with the finger ASTM D1640
Solidification drying
10 mil on the glass plate Draw down, press firmly with your fingers, and measure the time when the surface of the coated glass plate is free of any marks

It was confirmed that the epoxy paint for ships according to the present invention exhibits excellent physical properties.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, And such variations are within the scope of the present invention.

The scope of the present invention is defined by the following claims, and is not limited to the description of the specification, and all variations and modifications falling within the scope of the claims are included in the scope of the present invention.

Claims (9)

A two-component epoxy coating composition comprising a mixture of a base and a curing agent,
The subject matter includes a bisphenol-A epoxy resin,
Wherein the curing agent comprises an acrylic acid resin having a glass transition temperature (Tg) of 10 to 20 DEG C,
Wherein the acrylic acid resin comprises 8 to 13% by weight of dimethylaminoethyl methacrylate, 25 to 35% by weight of ethyl hexyl acrylate, 2 to 5% by weight of acrylic acid, monomer in an amount of 44 to 57% by weight. delete delete The method according to claim 1,
Wherein the acrylic acid resin has an acid value and an amine value of 32 mg-KOH / g to 37 mg-KOH / g. delete The method according to claim 1,
The subject application further comprises a pigment, a first solvent, and a second solvent. The method according to claim 1,
Wherein the curing agent further comprises a first solvent, wherein the curing agent comprises 75 wt% to 85 wt% of an acrylic acid resin and 10 wt% to 20 wt% of the first solvent. The method according to claim 1,
Wherein the subject and the curing agent are mixed in a mixing ratio in a ratio of 100: 60 to 100: 70 (weight ratio). The method according to claim 1,
Wherein the epoxy coating composition forms a coating film having a thickness of 75 to 125 占 퐉 and is used in an outer weathering zone of a ship.