KR20200039296A - Surfacer paint composition - Google Patents

Abstract

The present invention relates to a surfacer paint composition, and more specifically to a non-sanding surfacer paint composition which can be used in repair of automobiles, etc. The surfacer paint composition of the present invention comprises a resin part containing three types of acrylic resin and polyester resin having different glass transition temperatures. The surfacer paint composition of the present invention can maintain smoothness without a separate polishing process and form a paint film with excellent adhesion to top-coat paints such as water-soluble base coats, etc., while maintaining physical properties such as appearance, abrasiveness, dryness, thickening, spreadability, and ease of operation. Further, the surfacer paint composition of the present invention can be used in a non-sanding process while maintaining high quality even when applying a black color. Thus, a painting method using the surfacer paint composition of the present invention can exhibit an effect of shortening a paint film forming time and reducing heat treatment costs.

Description

Surfacer paint composition {SURFACER PAINT COMPOSITION}

The present invention relates to a surfacer coating composition. More specifically, the present invention relates to a non-sanding surfacer coating composition that can be used for automobile maintenance and the like.

Due to the enlargement of auto maintenance companies and consolidation between small companies, efforts are being made to shorten work time and reduce heat treatment costs in order to be competitive in the automotive repair and painting industry. Accordingly, the importance of the economics of paints and works in the automotive repair coating system is being emphasized more and more.

In particular, in the era of high oil prices, efforts are being made to reduce energy at each level of the industry, and in the field of automotive repair coatings, paints that can finish work quickly while consuming as little energy as possible are required.

Automobile repair is a process of restoring a wide range of damaged parts to their original form, ranging from small local vehicle damage areas to large three-panel damage repair. In recent years, the types of partial and small-area repairs are gradually increasing as the automobiles are upgraded.

The process for repairing damaged areas is largely divided into a surface adjustment step, a middle process step, and a top coat process step.

The surface adjustment step is an evaluation step of the damaged area, a surface preparation step including washing the damaged area and removing foreign substances, a polishing and cleaning of the old film to fill the grooves or scratches of the damaged area and to smooth the surface, and a putty application and drying step. , Putty polishing and clean steps.

The intermediate step includes a masking step of an area where painting is unnecessary, a degreasing step of the intermediate painting area, a primer-surface intermediate coating application step that increases corrosion and surface flatness of the damaged area, a intermediate coating drying step, a medium polishing and clean step, and the like. .

The top coat process step is the second masking step in areas where top coat is not required, the color paint application step to match the color, the transparent paint application step to impart luster and increase durability, and finally the light to finish the exterior of the coating cleanly And betting and evaluation steps.

Conventional two-component primer-surface paint composition is required to fill the irregularities of the lower extremity through spray painting and then smooth the surface through a polishing process. After this polishing process, the appearance of the top coat is not impaired and added. This is because the main required quality such as furnace adhesion and water resistance can be achieved. However, in recent years, the industry demand for a non-sanding surfacer that can be applied without a polishing process continues to improve economical efficiency and workability, but when applied as a non-sanding, it may not be applied with a top coat, for example, a water-soluble base coat due to lack of smoothness on the surface. Problems with poor adhesion have been proposed.

On the other hand, with the recent trend of color upgrading, research on the realization of a luxurious black color in the paint field is continuing, and the maintenance surfacer also needs to upgrade the black color.

The present invention maintains excellent physical properties such as appearance, abrasiveness, dryness, scalability, spreadability, and ease of operation of the formed coating film, while maintaining smoothness without a separate polishing process, and with top coats such as water-soluble base coats. An object of the present invention is to provide a surfacer coating composition having excellent adhesion.

In addition, the black color is also intended to provide a non-sanding surfacer coating composition capable of maintaining high quality such as gloss.

In order to achieve the above object, the present invention provides a surfacer coating composition comprising a resin part comprising three types of acrylic resins and polyester resins having different glass transition temperatures.

More specifically, the three types of acrylic resins have a surface transition coating composition comprising a first acrylic resin having a glass transition temperature of 70 ° C or more, a second acrylic resin having a temperature of 60 ° C or more and less than 70 ° C, and a third acrylic resin having a temperature of less than 60 ° C. to provide.

When the surfacer coating composition of the present invention is used, physical properties such as appearance, abrasiveness, dryness, scalability, spreadability, and ease of operation are maintained while maintaining smoothness without a separate polishing process, and top coat coatings such as water-soluble base coats A coating film with excellent adhesion to can be formed.

In addition, it can be used in a non-sanding process while maintaining high quality even when applying black color.

Therefore, the coating method using the surfacer coating composition of the present invention may exhibit an effect of reducing the cost by reducing the polishing time after forming the coating film.

Hereinafter, the present invention will be described in detail.

The surfacer coating composition of the present invention includes a resin part comprising three types of acrylic resins and polyester resins having different glass transition temperatures.

More specifically, the above three types of acrylic resins include a first acrylic resin having a glass transition temperature of 70 ° C or higher, a second acrylic resin having a glass transition temperature of 60 ° C to 70 ° C, and a third acrylic resin having a glass transition temperature of less than 60 ° C. It includes.

[Resin Department]

1st acrylic resin

The surfacer coating composition of the present invention includes a first acrylic resin having a glass transition temperature of 70 ° C or higher, more specifically 70 to 80 ° C, for example 70 to 75 ° C. If the glass transition temperature of the first acrylic resin is less than 70 ° C, the abrasiveness of the coating film decreases, and if it exceeds 80 ° C, the coating film is hard and the adhesion is lowered when coating the basecoat and clear. The first acrylic resin as described above may form the basic physical properties and appearance of the coating film, and impart smoothness to the coating film formed using the above.

The first acrylic resin is an acrylic monomer having at least one hydroxy group; Acrylic monomers having no hydroxy group; And aromatic vinyl monomers; those obtained by reacting may be used.

The acrylic monomer having at least one or more hydroxy groups is not limited thereto, for example, 2-hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylic Rate, 2-hydroxybutyl (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, 1,6- Hexanediol di (meth) acrylate, N-hydroxymethyl (meth) acrylamide, N- (1-hydroxyethyl) (meth) acrylamide, N- (2-hydroxypropyl) (meth) acrylamide or Mixtures of these can be used.

The acrylic monomer having no hydroxy group is not limited thereto, and C ₁ to C ₃₀ alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, and n-propyl (meth) Acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, amyl ( Meth) acrylate, iso-amyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, pentadecyl (meth) acrylate, dode Sil (meth) acrylate, iso-carbonyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, allyl (meth) acrylate, or mixtures thereof can be used.

As the aromatic vinyl-based monomer, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene or a mixture thereof can be used.

 The first acrylic resin may be random, block, alternating or graft copolymer.

In addition, the first acrylic resin has a solid content of 40 to 80% by weight, for example, 45 to 75% by weight, 50 to 70% by weight, 55 to 65% by weight, 60 to 65% by weight, and a hydroxyl value of 100 to 160 mgKOH / g, for example 100 to 150 mgKOH / g, 100 to 140 mgKOH / g, 105 to 130 mgKOH / g, 110 to 120 mgKOH / g, 110 to 115 mgKOH / g, weight average molecular weight (Mw) It may be preferable in terms of physical properties, dryness and smoothness of the coating film to be formed to use those of 3,000 to 8,000 g / mol, for example, 4,000 to 7,000 g / mol, and 5,000 to 6,000 g / mol.

In one embodiment, the first acrylic resin has a content of 5 to 20% by weight, for example 5 to 15% by weight of an acrylic monomer having a hydroxyl group based on 100% by weight of the first acrylic resin, and does not have a hydroxyl group. The acrylic monomer content is 20 to 50% by weight, for example 30 to 40% by weight, and the styrene monomer content (Styrene Monomer, SM (%)) is 20 to 50% by weight, for example 25 to 45% by weight, 30 It may be from 40 to 40% by weight, from 35 to 40% by weight, and may further include a solvent and an additive.

The surfacer coating composition may include the first acrylic resin in an amount of 1 to 25% by weight, for example, 5 to 20% by weight, and 5 to 15% by weight based on the total weight of the resin part. When the first acrylic resin is included within the above range, an effect of improving physical properties, drying properties and smoothness of the coating film formed may be particularly excellent. For example, if it is less than the above content range, the dryness and smoothness of the coating film formed by using it may be poor, and if it exceeds the above content range, problems such as appearance deterioration and workability such as glossiness of the coating film may be poor. have.

2nd acrylic resin

The surfacer coating composition of the present invention includes a second acrylic resin having a glass transition temperature of 60 ° C or more and less than 70 ° C, more specifically 62 ° C or more and less than 68 ° C, for example, 65 ° C. If the glass transition temperature of the second acrylic resin is less than 60 ° C, the abrasiveness of the coating film decreases, and if it exceeds 70 ° C, the adhesion of the coating film decreases. The second acrylic resin as described above may form the basic physical properties and appearance of the coating film, and impart smoothness to the coating film formed using the above.

The second acrylic resin is an acrylic monomer having at least one hydroxy group; Acrylic monomers having no hydroxy group; Aromatic vinyl monomers; And epoxy monomers; those obtained by reacting may be used.

An acrylic monomer having the hydroxy group; Acrylic monomers having no hydroxy group; And an aromatic vinyl monomer, but is not limited thereto, and the monomer disclosed with respect to the first acrylic resin may be used.

The epoxy monomer is not limited thereto, and for example, glycidyl acrylate, glycidyl methacrylate, glycidyl ester, glycidyl ether, or a mixture thereof may be used.

The second acrylic resin may be random, block, alternating or graft copolymer.

In addition, the second acrylic resin has a solid content of 40 to 80% by weight, for example, 45 to 75% by weight, 50 to 70% by weight, 55 to 65% by weight, and a hydroxyl value of 100 to 160 mgKOH / g, for example For example, 100 to 150 mgKOH / g, 105 to 140 mgKOH / g, 105 to 130 mgKOH / g, 110 to 125 mgKOH / g, and a weight average molecular weight (Mw) of 5,000 to 20,000 g / mol, for example 8,000 to The use of 15,000 g / mol may be preferable in view of the dryness, smoothness and adhesion of the top coat to the formed film.

In one embodiment, the second acrylic resin has a content of 5 to 20% by weight, for example 5 to 15% by weight of an acrylic monomer having a hydroxyl group based on 100% by weight of the second acrylic resin, and does not have a hydroxyl group. The acrylic monomer content is 10 to 40% by weight, for example 20 to 30% by weight, and the styrene monomer content (Styrene Monomer, SM (%)) is 10 to 40% by weight, for example 15 to 35% by weight, 20 To 30% by weight, 20 to 25% by weight, and an equivalent epoxy weight of 480 to 520 g / eq, for example 450 to 490 g / eq, 480 to 530 g / eq, and the balance Solvents and additives may be further included.

The surfacer coating composition may include 1 to 20% by weight, for example, 5 to 15% by weight, based on the total weight of the second acrylic resin. When the second acrylic resin is included within the above range, the effect of improving the dryness, smoothness and adhesion of the coating film formed may be particularly excellent. For example, if it is less than the above content range, the dryness and smoothness of the coating film formed by using this may be poor, and if it exceeds the above content range, problems such as adhesion and workability with a top coat may be poor.

3rd acrylic resin

The surfacer coating composition of the present invention includes a third acrylic resin having a glass transition temperature of less than 60 ° C, more specifically 40 ° C or more and less than 60 ° C, for example, 45 ° C or more and less than 60 ° C, 50 ° C or more and less than 60 ° C. When the glass transition temperature of the third acrylic resin is less than 40 ° C, the abrasiveness of the coating film decreases, and if it exceeds 60 ° C, adhesion decreases. The third acrylic resin as described above may form the basic physical properties and appearance of the coating film, and impart smoothness to the coating film formed using the above.

The third acrylic resin is an acrylic monomer having at least one hydroxy group; Acrylic monomers having no hydroxy group; Aromatic vinyl monomers; And epoxy monomers; those obtained by reacting may be used.

An acrylic monomer having the hydroxy group; Acrylic monomers having no hydroxy group; Aromatic vinyl monomers; And as an epoxy monomer is not limited thereto, it may be used the monomers disclosed for the first and second acrylic resin.

The third acrylic resin may be random, block, alternating or graft copolymer.

In addition, the third acrylic resin has a solids content of 40 to 80% by weight, for example 45 to 75% by weight, 50 to 70% by weight, 55 to 65% by weight, 55 to 60% by weight, and a hydroxyl value of 100 to 160 mgKOH / g, for example 110 to 155 mgKOH / g, 120 to 150 mgKOH / g, 125 to 145 mgKOH / g, 130 to 140 mgKOH / g, 135 to 140 mgKOH / g, weight average molecular weight (Mw) It may be preferable from the viewpoints of physical properties, dryness and smoothness of the coating film to be formed using 1,000 to 10,000 g / mol, for example, 2,000 to 8,000 g / mol, and 3,000 to 6,000 g / mol.

In one embodiment, the third acrylic resin has a content of 5 to 20% by weight, for example, 5 to 15% by weight of an acrylic monomer having a hydroxyl group based on 100% by weight of the third acrylic resin, and does not have a hydroxyl group. The acrylic monomer content is 10 to 40% by weight, for example 20 to 30% by weight, and the styrene monomer content (Styrene Monomer, SM (%)) is 5 to 30% by weight, for example 10 to 25% by weight, 10 To 20% by weight, 10 to 15% by weight, and an equivalent epoxy weight of 180 to 200 g / eq, for example, 180 to 200 g / eq, 200 to 300 g / eq, and balance Solvents and additives may be further included.

The surfacer coating composition may include 0.1 to 20% by weight, for example, 1 to 15% by weight of the third acrylic resin based on the total weight of the resin part. When the third acrylic resin is included within the above range, the effect of improving physical properties, drying properties, and smoothness of the coating film formed may be particularly excellent. For example, if it is less than the above content range, the dryness and smoothness of the coating film formed by using it may be poor, and if it exceeds the above content range, problems such as appearance deterioration and workability such as glossiness of the coating film may be poor. have.

Polyester resin

The surfacer coating composition of the present invention includes a polyester resin, and the polyester resin as described above can improve the spreadability of the composition to improve the ease of operation, and impart smoothness to the coating film formed by using the same.

The polyester resin has a solids content of 30 to 60% by weight, for example 35 to 55% by weight, 40 to 50% by weight, a hydroxyl value of 100 to 160 mgKOH / g, for example 110 to 155 mgKOH / g, 120 to 150 mgKOH / g, 130 to 145 mgKOH / g, 135 to 140 mgKOH / g, and weight average molecular weight (Mw) of 3,000 to 5,500 g / mol, for example 3,000 to 3,500 g / mol or 4,500 to 5,500 g The use of / mol may be preferable in terms of spreadability of the composition, physical properties of the coating film to be formed, and smoothness.

More specifically, the polyester resin is prepared by condensation reaction of an organic polyol, an organic acid and a polyacid, but is not limited thereto. The organic polyol may include a polyol having at least one kind of hydroxy group selected from glycerol, trimethylolpropane, and pentaerythritol. The organic acid may include those selected from the group consisting of saturated or unsaturated fatty acids, rosin acids (resin acids), linseed oil fatty acids, soybean oil fatty acids, naphthenic acid, tall oil, oxylic acid, and combinations thereof, wherein the fatty acids are neo Tecanoic acid (Neodecanoic acid) or isononanoic acid (Isononanoic acid). Also, the polyacid may be a non-aromatic polyacid (ie, an aliphatic polyacid). For example, in the group consisting of succinic acid, adipic acid, hexahydrophthalic anhydride (HPPA), cyclohexanedicarboxylic acid (CHDA), azelaic acid, sebacic acid, glutaric acid, cyclohexanediacid and combinations thereof. It can include what is selected.

In one embodiment, a polyester resin prepared by a condensation reaction of pentaerythritol, isononanoic acid and hexahydrophthalic anhydride (HPPA) may be used.

The surfacer coating composition may include the polyester resin in an amount of 0.01 to 10% by weight, for example, 0.1 to 5% by weight, and 1 to 5% by weight based on the total weight of the resin part. When the polyester resin is included within the above range, the effect of improving the spreadability of the composition, the properties of the coating film formed, and the smoothness may be particularly excellent. For example, if it is less than the content range, the smoothness of the coating film formed by using it may be unsuitable for the non-sanding process, and when it exceeds the content range, problems such as workability may be deteriorated.

Powder

The surfacer coating composition of the present invention includes powders, thereby giving the composition a role as a surfacer, and further improving rust resistance, impact resistance, abrasiveness, water resistance, and dispersibility.

The powder is not limited thereto, for example, at least one of fillers such as barium sulfate, talc, silicate, and silica, at least one of white pigments such as titanium dioxide (rutile), titanium dioxide (anatase), and zinc phosphate. , One or more of anti-rust pigments such as zinc oxide, and one or more of black pigments such as carbon black.

In one embodiment, the surfacer coating composition of the present invention, including carbon black, when using it can implement a black color excellent in smoothness and adhesion to the top coat without a separate polishing process.

The surfacer coating composition may include the powders in an amount of 30 to 60% by weight, for example, 35 to 55% by weight, and 40 to 50% by weight based on the total weight of the resin part.

Resin part solvent

The surfacer coating composition of the present invention may use a solvent commonly used in the coating composition, and an appropriate solvent may be used to control viscosity and dispersibility of the composition to improve workability. Examples include, but are not limited to, xylene, butyl acetate, ethyl acetate, isobutyl methyl ketone, solvent taffeta, 1-methoxy-2-acetoxypropane, propylene glycol methyl ether propionate, toluene, hexane, and the like. , The amount of the resin can be used as the remaining amount of the resin part. For example, it may be 10 to 30% by weight and 15 to 25% by weight based on the total weight of the resin part.

Other additives in the resin part

The surfacer coating composition of the present invention may further include other additives such as a wetting and dispersing agent, a urethane reaction accelerator, a silicone-based leveling agent, and an anti-settling agent within a range that does not impair the object of the present invention. The content of the other additives is not particularly limited, but considering the physical properties of the formed coating film, adhesion to the top coat, dryness and smoothness, etc., 0.01 to 5% by weight based on the total weight of the resin part, for example 0.1 to It may be desirable to be 1% by weight.

[Ministry of Curing]

The surfacer coating composition of the present invention may include a curing agent portion containing an isocyanate group-containing compound, and may be provided in a two-liquid form.

Isocyanate group-containing compounds

The isocyanate group-containing compound is used as a curing agent that reacts with a hydroxyl group in the resin part to form urethane, and is not particularly limited as a specific type, but it is preferable to use an aliphatic isocyanate compound without yellowing, for example, hexa Methylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclo hexyl methane diisocyanate, tetramethyl xylene diisocyanate or mixtures thereof can be used.

The content of the isocyanate group-containing compound may be 40 to 80% by weight, for example, 50 to 75% by weight, 60 to 70% by weight based on the total weight of the curing agent, and in the case of the content range, form a stabilized cured product Therefore, it may be desirable to improve the properties of the coating film.

Hardener part solvent

The curing agent portion may improve the workability by adjusting the storage stability of the curing agent portion, the viscosity and dispersibility of the composition, including the residual amount of solvent, and is not particularly limited as the type, and the solvent disclosed as the solvent of the resin portion may be used. have.

The content of the curing agent portion solvent may be preferably 15 to 45% by weight, for example, 25 to 40% by weight based on the total weight of the curing agent portion.

Other additives

The surfacer coating composition of the present invention may further include other additives such as a water absorbent such as triethyl ortho formate and a drying accelerator (Dibutyltin dilaurate). The content of the other additives is not particularly limited, but considering the physical properties of the formed coating film, adhesion to a top coat, dryness and smoothness, etc., 0.01 to 5% by weight based on the total weight of the curing agent, for example 0.1 to It may be desirable to be 1% by weight.

In one embodiment, the surfacer coating composition of the present invention can be used in a non-sanding process. More specifically, using the surfacer coating composition of the present invention, after applying the coating composition to the substrate, it is possible to apply the topcoat without a separate drying and / or polishing process.

Hereinafter, examples and the like will be described in detail to help understanding of the present invention. However, the embodiments according to the present invention can be modified in many different forms, and the scope of the present invention should not be construed as being limited to the following examples. The embodiments of the present invention are provided to more fully explain the present invention to those having average knowledge in the field to which the present invention pertains.

[Preparation of surfacer coating composition]

Preparation of Examples and Comparative Examples

A surfacer coating composition was prepared with the composition and content shown in Table 1 below.

Manufacturing method

Mill Base Manufacturing Process: After mixing the 1st acrylic resin and the 2nd acrylic resin and the solvent and stirring with a dispersant, the pigment and a solvent were added and dispersed (RINGMILL). Dispersion particle size 20㎛.

Finishing process: As described above, the third acrylic resin and the polyester resin were added to the mill base where dispersion was completed, followed by stirring, followed by addition of additives, followed by stirring for 1 hour.

Ingredient (% by weight) Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Resin 1st acrylic resin 13 13 0 13 13 2nd acrylic resin 10 10 10 0 10 3rd acrylic resin 6 0 6 6 6 Polyester resin 3 3 3 3 - Pigment 46 46 46 46 46 solvent 17 23 30 27 20 additive 5 5 5 5 5 Gross weight 100 100 100 100 100 Hardener Isocyanate group-containing compounds 66 66 66 66 66 solvent 33 33 33 33 33 additive One One One One One Gross weight 100 100 100 100 100

-1st acrylic resin: HPMA (hydroxy propyl methacrylate), MMA (methyl methacrylate), styrene and HEMA (hydroxy ethyl methacrylate) copolymer, solid content 64%, hydroxyl value 113 mgKOH / g, Tg 72 ° C, Mw 5,500 g / mol, SM content 36%, HEMA content 10%.

-Second acrylic resin: HPMA, MMA, epoxy monomer (Hexion Co., CARDURA E-10P, glycidyl ester), styrene and HEMA copolymer, solid content 60%, hydroxyl value 120 mgKOH / g, Tg 65 ℃, Mw 10,000 g / mol, SM content 24%, HEMA content 11%.

-3rd acrylic resin: HPMA, MMA, epoxy monomer (Hexion Co., CARDURA E-10P, glycidyl ester), styrene and HEMA copolymer, solid content 58%, hydroxyl value 139 mgKOH / g, Tg 32 ℃, Mw 4,000 g / mol, SM content 13%, HEMA content 10%.

-Polyester resin: polymer of PENTAERYTHRITOL, acid ISONONANOIC ACID and acid HHPA (HEXAHYDROPHTHALIC ANHYDRIDE), solid content 45%, hydroxyl value 137 mgKOH / g.

Ingredient (% by weight) Example 2 Example 3 Example 4 Comparative Example 5 Resin 1st acrylic resin 5 14 6 11 2nd acrylic resin 9 5 14 9 3rd acrylic resin 12 6 4 9 Polyester resin 3 4 5 0 Pigment 46 46 46 46 solvent 20 20 20 20 additive 5 5 5 5 Gross weight 100 100 100 100 Hardener Isocyanate group-containing compounds 66 66 66 66 solvent 33 33 33 33 additive One One One One Gross weight 100 100 100 100

-1st acrylic resin: HPMA (hydroxy propyl methacrylate), MMA (methyl methacrylate), styrene and HEMA (hydroxy ethyl methacrylate) copolymer, solid content 64%, hydroxyl value 113 mgKOH / g, Tg 72 ° C, Mw 5,500 g / mol, SM content 36%, HEMA content 10%.

-Second acrylic resin: HPMA, MMA, epoxy monomer (Hexion Co., CARDURA E-10P, glycidyl ester), styrene and HEMA copolymer, solid content 60%, hydroxyl value 120 mgKOH / g, Tg 65 ℃, Mw 10,000 g / mol, SM content 24%, HEMA content 11%.

-3rd acrylic resin: HPMA, MMA, epoxy monomer (Hexion Co., CARDURA E-10P, glycidyl ester), styrene and HEMA copolymer, solid content 58%, hydroxyl value 139 mgKOH / g, Tg 32 ℃, Mw 4,000 g / mol, SM content 13%, HEMA content 10%.

-Polyester resin: PENTAERYTHRITOL, ISONONANOIC ACID and polymer of HHPA and epoxy resin, solid content 60%, hydroxyl value 140 mgKOH / g

[Physical property evaluation]

Using the surfacer coating composition prepared above, the physical properties of the composition and the coating film were evaluated by the following method, and the results are shown in Table 3 below.

Appearance, polished

After mixing at the recommended mixing ratio on the electrodeposition specimen (40 * 45 cm), paint it in the same pattern, dry it at room temperature at 20 ° C, evaluate the spreadability, stainability, and fillability of the paint, and polish the final dried coating film (60 degrees) with a polisher Record after measurement.

Adhesion

After cutting the crosscut sheaths at 2 mm intervals, after rubbing and attaching to the coating film with NICHIBAN TAPE, the act of pulling strongly upward was performed 4 times on the same site, and the number of coating films adhered without peeling (100 standards) was checked.

Dryness

After mixing the electrodeposition specimens (40 * 45 cm) at the recommended mixing ratio, painting them in the same pattern, drying at room temperature at 20 ° C, and measuring the tack-free time when pressed with a constant force with a finger.

Water resistance

Impregnated in a constant temperature bath at 40 ° C. for 7 days to measure the surface condition (swelling, bubbles) and adhesion of the coating film. After removing the water and dirt on the specimen, leave it at room temperature for 1 hour and test the adhesion.

Impact resistance

Using a DUPONT IMPACT TEST machine, the weight of 500 g was dropped 50 cm at room temperature at 20 ° C. to measure the degree of damage to the coating film. Record the maximum height when there is no breakage of the coating.

Example Comparative example Item One 2 3 4 One 2 3 4 5 Appearance, polished 69 65 68 69 70 66 65 63 71 Adhesion 100/100 100/100 99/100 100/100 90/100 95/100 80/100 89/100 82/100 Dryness 10 minutes 11 minutes 10 minutes 12 minutes 14 minutes 15 minutes 11 minutes 9 minutes 13 minutes Water resistance No bubbles
100/100 No bubbles
100/100 No bubbles
100/100 No bubbles
100/100 No bubbles
50/100 No bubbles
100/100 Gloss loss
50/100 Gloss loss
60/100 Gloss loss
50/100 Impact resistance 50 50 50 50 50 50 40 30 40

As can be seen in Table 3 above, it was confirmed that the coating films formed using Examples 1 to 4 were excellent in physical properties of appearance, gloss, adhesion, dryness, water resistance, and impact resistance.

Claims (7)

It includes a resin part comprising three types of acrylic resin and polyester resin having a different glass transition temperature,
The three types of acrylic resin
The first acrylic resin having a glass transition temperature of 70 ° C or higher,
A second acrylic resin having a glass transition temperature of 60 ° C or more and less than 70 ° C, and
A surfacer coating composition comprising a third acrylic resin having a glass transition temperature of less than 60 ° C.
The method according to claim 1,
The first acrylic resin has a solid content of 40 to 80% by weight, a hydroxyl value of 100 to 160 mgKOH / g, and a weight average molecular weight (Mw) of 3,000 to 8,000 g / mol.
The method according to claim 1,
The second acrylic resin has a solid content of 40 to 80% by weight, a hydroxyl value of 100 to 160 mgKOH / g, and a weight average molecular weight (Mw) of 5,000 to 20,000 g / mol.
The method according to claim 1,
The third acrylic resin solid content is 40 to 80% by weight, the hydroxyl value is 100 to 160 mgKOH / g, the weight average molecular weight (Mw) is a surfacer coating composition comprising a 1,000 to 10,000 g / mol.
The method according to claim 1,
The polyester resin has a solid content of 30 to 60% by weight, a hydroxyl value of 100 to 160 mgKOH / g, and a weight average molecular weight (Mw) of 3,000 to 5,500 g / mol. The method according to claim 1,
The resin part is 1 to 25% by weight of the first acrylic resin based on the total weight of the resin part, 1 to 20% by weight of the second acrylic resin, 0.1 to 20% by weight of the third acrylic resin, 0.01 to 10% by weight of the polyester resin A surfacer coating composition comprising. The method according to claim 1,
The first acrylic resin is an acrylic monomer having at least one hydroxy group; Acrylic monomers having no hydroxy group; And aromatic vinyl monomers; those obtained by reacting;
The second and third acrylic resins include acrylic monomers having at least one hydroxy group; Acrylic monomers having no hydroxy group; Aromatic vinyl monomers; And epoxy monomer; surfacer coating composition comprising the obtained by reacting.