KR100638263B1 - Paint composition for coating non-metal - Google Patents

Abstract

The present invention relates to a paint composition coated on non-metals such as refrigerator doors, air conditioner front panels, and glass tiles for interior and exterior construction, and includes 35 to 80% by weight of an acrylic resin having a hydroxyl group and a block isocyanate resin of hexamethylene diisocyanate 5 To 15% by weight, 1 to 10% by weight of epoxy silane, 0.1 to 4% by weight of aromatic block sulfonic acid as reaction catalyst, 5 to 30% by weight of solvent, and 0.2 to 2% by weight of antifoaming agent, and 0.1 to 2% by weight of thickener It provides a high-performance one-component non-metallic coating composition having excellent adhesion, chemical resistance, ultraviolet resistance, water resistance and the like.

Description

Paint composition for coating non-metal

The present invention relates to a coating composition for one-component nonmetallic coatings, and more particularly, to a coating composition for nonmetallic coatings having excellent coating properties such as high hardness, chemical resistance, and adhesion to glass plates such as glass and tiles.

Industrial glass plate refers to glass panels such as glass panels for refrigerators and air conditioners, glass panels for furniture fronts, glass tiles for interiors, and glass for building exterior materials.

The resin composition used in the paint for glass is polyester and epoxy resins, but it has a problem of poor physical properties in adhesion and water resistance. It is used as a separate two-component type. Therefore, the paint has to be consumed within a certain time due to the pot life, and the remaining paint must be discarded because of the hassle of mixing the main agent and the curing agent.

Currently, to improve this problem, one-component paints to which acrylic / melamine / epoxy mixed resin compositions are applied are used, but water resistance and adhesion are lowered, and storage stability is particularly poor.

The adhesion and water resistance is the most important property in the physical properties of the paint for glass, it is necessary to maintain the adhesion for a long time due to the characteristics of household appliances, furniture, buildings used for a long time, the resin composition used in the paint is completely cured glass and strong An attachment must be formed. This prevents a defect due to a poor adhesion of the coating film when exposed to the external environment for a long time.

Looking at the coating process of the general industrial glass plate, first wash the glass body and paint the pearl or metallic by spraying method, and then paint solid color directly to the top without drying, and dried at 150 ℃ ~ 180 ℃ for 10 ~ 20 minutes. Obtain the finished product, or after coating once with silkscreen printing, after drying the film after the final top coat, dry it at 150 ℃ ~ 180 ℃ for 10 ~ 20 minutes, and apply the finished product by coating 2 to 8 times according to the design.

In the case of a paint using an acrylic / melamine / epoxy mixed resin composition, chemical reactions with a curing agent, a catalyst, and the like generally occur in the coating composition, resulting in poor adhesion and storage stability of the coating film.

As described above, in order to improve the performance of adhesion, moisture resistance, solvent resistance, chemical resistance, ultraviolet resistance, cold resistance, and boiling resistance of industrial glass plates currently used in general, high functional glass coating compositions are required. In addition, paint composition with excellent storage stability of one-component paints is required to reduce paint loss and environmental pollution.

In addition, the coating method on the coating is changed to not only the conventional spray coating method but also silk screen coating method, so that it is possible to eliminate the pattern and color that cannot be expressed by the conventional spray coating, and the loss of the paint caused by the spray coating and the environmental pollution caused by this. It is desirable to reduce.

Accordingly, an object of the present invention is to provide a coating composition for a high-functional nonmetallic coating having excellent adhesion, moisture resistance, solvent resistance, chemical resistance, ultraviolet resistance, cold resistance, boiling resistance, and storage stability.

Non-metallic coating composition of the present invention for achieving the above object is 35 to 80% by weight of acrylic resin having a hydroxyl value of 10 to 40 mgKOH / g, an average molecular weight of 10,000 to 50,000, the glass transition temperature of 25 to 60 ℃; 5 to 15% by weight of hexamethylene diisocyanate-based block isocyanate resin; 1 to 10% by weight epoxy-based silane; 0.1-4% by weight of aromatic block sulfonic acid as a reaction catalyst; Solvent 5-30% by weight; And it is characterized in that it comprises 0.2 to 2% by weight of the defoaming agent and 0.1 to 2% by weight of the thickener as an additive.

The present invention will be described in more detail as follows.

The coating composition for nonmetallic coating of this invention contains an acrylic resin, a block isocyanate resin, an epoxy silane, and aromatic block sulfonic acid as a reaction catalyst.

(1) acrylic resin

First, it is preferable that the acrylic resin which is the main body of the resin composition for glass has an acrylic backbone structure containing a hydroxyl group.

The content of the acrylic resin having such a hydroxyl group is 35% to 80% by weight of the total coating composition, when the content is less than 35% by weight is limited in the adhesion of the substrate and the solid content control and pigment content selection of the paint If it is not preferable and solvent content exceeds 80 weight%, solvent resistance will fall significantly and it is not preferable.

The acrylic resin that can be used in the present invention is an acrylic resin having a hydroxyl value (mgKOH / g) of 10 to 40 and a weight average molecular weight of 10,000 to 50,000 using an acrylic monomer. It is more preferable if it is an acrylic resin manufactured so that the glass transition temperature of the said acrylic resin may have the characteristic value which is 25-60 degreeC.

If the hydroxyl value of the acrylic resin is less than 10, the reduction of the overall coating properties due to the lack of chemical bonds during the curing reaction, and if the hydroxyl value is greater than 40, the amount of the curing agent is required to be a problem in economic efficiency.

In addition, when the weight average molecular weight of the acrylic resin is less than 10,000, the molecular weight is reduced to weaken the overall physical properties of the coating film, and having a weight average molecular weight greater than 50,000 is poor in solubility and difficulties in the synthesis of resin.

More preferably, an acrylic resin having a glass transition temperature of 25 ° C. to 60 ° C. is used. If the glass transition temperature is lower than 25 ° C., the film hardness is weak, and scratch resistance is weak. If the glass transition temperature is higher than 60 ° C., the resin is excessive. As the hardness increases, the coating breakage occurs.

Such an acrylic resin includes an acrylic monomer having a hydroxyl group as an essential component. In the present invention, hydroxy-ethyl acrylate, hydroxy-propyl acrylate, hydroxy-butyl acrylate, hydroxy-methyl methacrylate, and hydroxy At least one selected from acrylic monomers having a hydroxyl group such as ethyl methacrylate, hydroxy-propyl methacrylate and hydroxy-butyl methacrylate is used. In addition to the acrylic monomer having a hydroxyl group, a common monomer used in the production of acrylic resin can be used together. Such monomers include styrene, methyl acrylate, methyl methacrylate, ethyl acrylate, 2-ethylhexyl acrylate, normal-butyl acrylate, butyl acrylate, lauryl acrylate and trimethylol, which are acrylic and vinyl monomers. And at least one monomer selected from the group consisting mainly of propanetriacrylate, trimethacrylate, hexanediol diacrylate, acrylamide, methacrylamide, vinyl chloride, methacrylic acid and acrylic acid. It is preferable to mix the acrylic monomer which has a hydroxyl group by 1: 1 to 4: 1 ratio of a normal monomer.

In the case of the conventional two-component non-metal coating coating composition, the adhesive property is improved by providing a silane group or an epoxy group to the acrylic monomer when preparing the acrylic resin. It is preferable not to use because of poor storage performance.

(2) Block isocyanate resin of hexamethylene diisocyanate type

In the coating composition of the present invention, it is preferable to include hexamethylene diisocyanate-based block isocyanate resin in an amount of 5 to 15% by weight in the total composition. If the content is less than 5% by weight, the overall coating film property decreases due to the lack of chemical bonds. This is because when it exceeds 15% by weight, cracking and deterioration of storage properties of the coating film appear.

Specific examples of the hexamethylene diisocyanate-based block isocyanate resin include Desmodur BL3175 (product name) of Bayer, Germany or CORONATE-2507 (product name) of Japan Polyurethane Industry.

The mixing ratio of the acrylic resin and the hexamethylene diisocyanate-based block isocyanate resin was applied as a ratio of 5/1 to 12/1 (acrylic resin / isocyanate resin) as a nonvolatile content ratio.

(3) epoxy clock silane

Paints using only acrylic resins and melamine resins exhibit poor physical properties in adhesion and boiling resistance in coating properties.

In order to compensate for the weak adhesion and boiling resistance properties of the epoxy-based silane is introduced, the content is preferably 1 to 10% by weight of the total coating composition. If the epoxy-based silane is included in less than 1% by weight of the total coating composition, the adhesion is lowered, if it exceeds 10% by weight, the non-reactive substance remains and becomes vulnerable to solvent resistance and water resistance.

Specific examples of the epoxy silanes include β- (3,4-epoxycyclohexyl) -ethyltrimethoxy silane, γ-glycidoxy propyl methyl diethoxy silane, γ-glycidoxy propyl trimethoxy silane, and γ-glycidoxy Cipropyl triethoxy silane.

(4) reaction catalyst

Another factor affecting the degree of curing of the coating film is a reaction catalyst, and in the present invention, a strongly acidic aromatic block sulfonic acid is applied.

In the block agent of the block acid catalyst, an amine is generally used. When the amine block acid catalyst is applied to a non-metal, especially glass paint as in the present invention, the amine reacts and adversely affects the storage property, causing thickening and gelation. Or it is preferable to use the acid catalyst blocked with the urethane type polymer.

The amount of the acid catalyst which is the reaction catalyst is 0.1 to 4% by weight of the total coating composition, because when it is out of this range, negative effects such as the degree of curing of the coating film appear.

(5) solvent

Solvent, one of the factors affecting workability when painting paints, depends on the painting method.

When painting with silk screen printing, a slow drying solvent should be used due to the characteristics of the coating method. Specifically, butyl cellulsolve, methyl salicylate, butyl carbitol, coco sol 150, coco sol 200, propylene glycol mono At least one dry solvent such as methyl acetate, cyclohexanone, normal butanol, isobutanol and isopron is sprayed by xylene, toluene, isopropyl alcohol, ethanol, methanol methyl ethyl ketone, and butyl acetate. 5 to 30% by weight of one or more solvents, such as when the solvent is less than 5% by weight of the paint due to the volatility of the solvent due to the volatilization of the solvent during painting work, the appearance and color of the coating is poor, when the paint exceeds 30% by weight Problems such as sedimentation and heart cake can occur.

(6) defoamer

Due to the characteristics of silkscreen printing, it is preferable to include a very strong antifoaming agent in 0.2 to 2% by weight of the total composition. The content is less than 0.2% by weight, and the antifoaming property causes bubbles to remain in the coating film, resulting in poor appearance. It is because when it exceeds%, the interlayer adhesion of a coating film will fall and drying time will become long.

Specific examples of the antifoaming agent include FOAMEX (product name), AIREX930 (product name) from Tego, Germany, KF96 (product name) and KS66 (product name) from Shin-Etsu Japan.

(7) thickener

In order to prevent the sedimentation of pigment components during paint storage, to improve the flowability during painting, and especially to improve the transparency and color of the paint, a liquid thickener should be used, and it is preferable to use 0.1 to 2% by weight of the total composition. If the content is less than 0.1% by weight, sedimentation of the pigment component occurs during storage of the paint, and when the content exceeds 2% by weight, the thixotropy and viscosity of the paint are increased, resulting in appearance defects.

Specific examples of the thickener include BYK-410 (product name) of BEIKEI, Germany, and Troythix21BA (product name) of Troy, USA.

Hereinafter, the present invention will be described in detail with reference to the following examples, but the scope of the present invention is not limited thereto.

<Production of Acrylic Resin>

The biggest feature of acrylic resin is that it controls the hydroxyl value, monomer composition and molecular weight of acrylic polyol resin, and does not contain existing silane group or epoxy group, and it does not contain existing silane group or epoxy group. It is to be excellent.

Synthesis Example 1

40 wt% of Cocosol # 100 was added to a four-necked flask equipped with a thermometer and a cooler, and the temperature was increased to 120 ° C. Next, as a monomer, 20% by weight of methyl methacrylate, 12% by weight of styrene, 10% by weight of butyl acrylate, 5% by weight of 2-hydroxyethyl methacrylate, and tertiary-butylperoxy-benzoate 2.5 as an initiator The mixture consisting of weight percent was added dropwise over 3 hours. Next, after holding at 120 degreeC for 2 hours, the liquid mixture obtained by melt | dissolving 0.5 weight% of tertiary butyl peroxy- benzoate which is an initiator in 10 weight% of cocosol # 100 was dripped for 10 minutes. Then, the mixture was kept for 2 hours and reacted to obtain an acrylic polyol. The viscosity, glass transition temperature, hydroxyl value, and weight average molecular weight of the obtained acrylic polyol were measured. The component ratios used and the results are shown in Table 1 below.

Synthesis Example 2

40 wt% of Cocosol # 100 was added to a four-necked flask equipped with a thermometer and a cooler, and the temperature was increased to 120 ° C. Next, as a monomer, 20% by weight of methyl methacrylate, 12% by weight of styrene, 5% by weight of butyl acrylate, 10% by weight of 2-hydroxyethyl methacrylate, and tertiary-butylperoxy-benzoate 2.5 as an initiator The mixture consisting of weight percent was added dropwise over 3 hours. Next, after holding at 120 degreeC for 2 hours, the liquid mixture obtained by melt | dissolving 0.5 weight% of tertiary butyl peroxy- benzoate as an initiator in 10 weight% of cocosol # 100 was dripped for 10 minutes. Then, the mixture was kept for 2 hours and reacted to obtain an acryl polyol. The viscosity, glass transition temperature, hydroxyl value, and weight average molecular weight of the obtained acrylic polyol were measured. The component ratios used and the results are shown in Table 1 below.

Synthesis Example 3

40 wt% of Cocosol # 100 was added to a four-necked flask equipped with a thermometer and a cooler, and the temperature was increased to 120 ° C. Next, 20% by weight of methyl methacrylate, 18% by weight of styrene, 5% by weight of butyl acrylate, 5% by weight of 2-hydroxyethyl methacrylate and 1.5% of tertiary-butylperoxy-benzoate as an initiator The mixture consisting of% was added dropwise over 3 hours. Next, after holding at 120 degreeC for 2 hours, the liquid mixture obtained by melt | dissolving 0.5 weight% of tertiary butyl peroxy- benzoate which is an initiator in 10 weight% of cocosol # 100 was dripped for 10 minutes. Then, the mixture was kept for 2 hours and reacted to obtain an acrylic polyol. The viscosity, glass transition temperature, hydroxyl value, and weight average molecular weight of the obtained acrylic polyol were measured. The component ratios used and the results are shown in Table 1 below.

Comparative Synthesis Example 1

40 wt% of Cocosol # 100 was added to a four-necked flask equipped with a thermometer and a cooler, and the temperature was increased to 120 ° C. Next, 25% by weight of methyl methacrylate, 7% by weight of butyl acrylate, 5% by weight of 2-hydroxyethyl methacrylate, 10% by weight of trimethoxysilaneethyl methacrylate and tertiary-butyl as an initiator A mixture consisting of 2.5% by weight of peroxy-benzoate was added dropwise over 3 hours. Next, the mixture was maintained at 120 ° C for 2 hours, and then a mixed solution obtained by dissolving 0.5 wt% of initiator-butylperoxy-benzoate in 10 wt% of Cocosol # 100 was added dropwise for 10 minutes. Then, the mixture was kept for 2 hours and reacted to obtain an acrylic polyol. The viscosity, glass transition temperature, hydroxyl value, and weight average molecular weight of the obtained acrylic polyol were measured. The component ratios used and the results are shown in Table 1 below.

Comparative Example 2

40 wt% of Cocosol # 100 was added to a four-necked flask equipped with a thermometer and a cooler, and the temperature was increased to 120 ° C. Next, 5% by weight of styrene as a monomer, 15% by weight of methyl methacrylate, 7% by weight of butyl acrylate, 10% by weight of 2-hydroxyethyl methacrylate, 10% by weight of glycidyl methacrylate and tertiary as an initiator A mixture consisting of 2.5% by weight of -butylperoxy-benzoate was added dropwise over 3 hours. Subsequently, after holding at 120 degreeC for 2 hours, the liquid mixture obtained by melt | dissolving 0.5 weight% of tertiary butyl peroxy- benzoate as an initiator in 10 weight% of cocosol # 100 was dripped at 30 minutes. Then, the mixture was kept for 2 hours and reacted to obtain an acrylic polyol. The viscosity, glass transition temperature, hydroxyl value, and weight average molecular weight of the obtained acrylic polyol were measured. The component ratios used and the results are shown in Table 1 below.

division Synthesis Example 1 Synthesis Example 2 Synthesis Example 3 Comparative Synthesis Example 1 Comparative Synthesis Example 2 Viscosity Z2 Z3 Z4 Z3 Z3 Hydroxyl value 15 30 15 15 30 Glycidyl methacrylate (GMA) - - - - 10% Silane Monomer - - - 10% - Tg 50 ℃ 45 ℃ 50 ℃ 45 ℃ 50 ℃ Molecular Weight 15000 15000 25000 15000 15000

In the said Table 1, a viscosity is measured with the Gardner viscometer at 25 degreeC, and a hydroxyl value is a value with respect to resin solid content.

<Production of Coating Composition>

Examples 1-3 and Comparative Examples 1-2

As shown in Table 2 below, a one-component glass coating composition was prepared by using a block isocyanate resin, an epoxy silane, an acid catalyst, and an additive in an acrylic resin obtained in Synthesis Examples 1 to 3 and Comparative Examples 1 to 2. It was.

division Example (g) Comparative Example (g) One 2 3 One 2 3 4 5 Theme composition Synthesis Example 1 Resin 70 - - - - 70 - - Synthesis Example 2 Resin - 65 - - - - 65 - Synthesis Example 3 Resin ^{- -} 70 - - - - - Acrylic resin - - - - - - - 80 Comparative Synthesis Example 1 Resin - - - 70 - - - - Comparative Synthesis Example 2 Resin - - - - 65 - - - Melamine resin - - - - - - - 9 Block isocyanate1 5 8 5 5 8 - 8 - Block isocyanate 2 - - - 3 - 5 - - Epoxy resin - - - - - - - 3 Epoxy-based silane 3 3 5 - - 3 - - Amino silane - - - - 3 - 3 - Acid catalyst One One 1.2 1.2 One One One 0.5 solvent 19 21 17 19 21 19 21 6 additive 2 2 1.8 1.8 2 2 2 1.5 Total (g) 100 100 100 100 100 100 100 100 Representative examples of the components used in the above paint formulations are as follows. * Block isocyanate resin 1: Hexamethylene diisocyanate (Desmodur-BL3175) * Block isocyanate resin 2: Xylene diisocyanate * Epoxy silane: 3-Glycidoxypropyltrimethoxy silane * Imino-based silane: 3-Aminopropyltriethoxy silane * Solvent: Xylene, dibuthylene glycol, Methyl salicylate * Acid catalyst: Nacure-5414 * Additives: Defoamer, thickener included * Non-volatile content of acrylic resin: 45% * Non-volatile content of block isocyanate: 70%

Physical property evaluation test of coating composition for glass

Silk screen paint in which 15 parts by weight of aluminum foil and 5 parts by weight of a colorant are mixed with respect to the total amount of the coating composition obtained in order to evaluate adhesion and various physical properties of the coating composition for one-component glass obtained according to the mixing ratios of the examples and comparative examples. Two kinds of paints for spraying a mixture of 50 parts by weight of a quick-drying solvent, 8 parts by weight of aluminum foil and 2 parts by weight of a colorant were used for the evaluation of physical properties.

For evaluation of the physical properties of the present invention, the glass plate treated with water was coated with a thickness of 25 to 30 microns and 50 to 60 microns with a spray, and evaluated by the following physical property evaluation test method. The drying conditions of the said paint were 15 minutes at 180 degreeC. Evaluation results of the physical properties of the coating composition for glass are shown in Table 3 below.

Property item division Example Comparative example One 2 3 One 2 3 4 Adhesion 1mm cross cut 100/100 100/100 100/100 98/100 90/100 100/100 100/100 Pencil hardness Mitsubishi pencil 3H 3H 3H 5H 3H 4H 3H Boiling water resistance Soak in 98 ± 2 ℃ boiling water for 1 hour Good Good Good Peeling discoloration Good Good Solvent resistance Ethanol, IPA rubbing 50 times 50 times 50 times 50 times 50 times 20 times 50 times 50 times Heat resistance -20 ℃ / 2hrs ↔60 ℃, RH90 ↑ 2hrs 100 times Good Good Good Good discoloration Good Good Moisture resistance 50 ℃ / RH90 240 hours Good Good Good Good discoloration Good Good UV-resistant QUVB 500 hours Good Good Good Good discoloration Good Good Alkali resistance 5% NaOH, 24 hours (SPOT TEST) Good Good Good Good Good Good Good Acid resistance 5% H ₂ SO ₄ , 24 hours (SPOT TEST) Good Good Good Good Good Good Good Repainting 1mm cross cut Good Good Good Good Good Gelation Good Zhejiang 60 ℃ / 300 hours Good Good Good Gelation Thickening Gelation Thickening * In case of Comparative Example 3, thickening phenomenon occurred in paint production. * Storage performance was judged to be good when the viscosity was changed within the initial viscosity of 901 KU ± 10%. * UV resistance was judged to be good when glossiness was maintained above 90% and ΔE: below 1.5.

As described in detail above, the one-component glass coating composition of the present invention does not need to mix the main agent and the curing agent during the painting work by one-component forming the conventional two-component glass coating composition, and has a pot life of the two-component type. It eliminates the limitation of the painting work time, and also reduces the loss of paint, and also has excellent weather resistance, high hardness, chemical resistance, adhesion, boiling resistance, etc. of the conventional two-component glass coating composition. The physical properties of the coating film are shown to be equal to or higher, and in addition, there is no storage stability problem of the acrylic, melamine, and epoxy-based mixed compositions.

While the invention has been described with reference to the examples, it will be understood that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below.

Claims (6)

      35 to 80% by weight of an acrylic resin having a hydroxyl value of 10 to 40, an average molecular weight of 10,000 to 50,000, and a glass transition temperature of 25 ° C to 60 ° C; 5 to 15% by weight of hexamethylene diisocyanate-based block isocyanate resin; β- (3,4-epoxycyclohexyl) -ethyltrimethoxy silane, γ-glycidoxy propyl methyl diethoxy silane, γ-glycidoxy propyl trimethoxy silane, γ-glycidoxy propyl triethoxy silane 1 to 10% by weight of one or two or more epoxy-based silanes selected from among; 0.1-4% by weight of aromatic block sulfonic acid as a reaction catalyst; 5-30 wt% of a solvent; Coating composition for a one-component non-metallic coating comprising 0.2 to 2% by weight of the defoaming agent and 0.1 to 2% by weight of the thickener as an additive.       The method of claim 1, wherein the acrylic resin is an acrylic monomer having a hydroxyl group, hydroxy-ethyl acrylate, hydroxy-propyl acrylate, hydroxy- butyl acrylate, hydroxy-methyl methacrylate, hydroxy-ethyl acryl A coating composition for one-component non-metallic coating, characterized in that it contains at least one monomer selected from the group consisting of latex, hydroxy-propyl methacrylate and hydroxy-butyl methacrylate. delete The coating composition of claim 1, wherein the aromatic block sulfonic acid is blocked with an epoxy or urethane polymer.        The solvent according to claim 1, wherein the solvent is butyl celusolve, methyl salicylate, butyl carbitol, coco sol 150, coco sol 200, propylene glycol monomethyl acetate, cyclohexanone, normal butanol, isobutanol when coated by silk screen printing. And a one-component non-metallic coating composition characterized by using at least one solvent selected from isopron.        The coating composition of claim 1, wherein the solvent is one or more solvents selected from xylene, toluene, isopropyl alcohol, ethanol, methanol methyl ethyl ketone and butyl acetate in the spray coating method.