KR20210017543A - Aqueous PCM Coating Composition - Google Patents

Abstract

The present invention provides an eco-friendly, aqueous pre-coated metal (PCM) coating composition having excellent flexibility, hardness, gloss and weather resistance, and a PCM steel sheet to which the same is applied.

Description

Water-soluble PCM coating composition {Aqueous PCM Coating Composition}

The present invention provides an eco-friendly water-soluble PCM (Pre-Coated Metal) coating composition and a PCM steel sheet to which the same is excellent in flexibility, hardness, gloss and weather resistance.

PCM paint is also referred to as coil coating paint, and it is coated using a roll on a steel plate with a uniform surface, so that the coating speed is very fast and a uniform coating film can be formed. It is suitable for mass production.

Existing PCM paints contain a large amount of highly volatile organic solvents, so there is a problem that the paint manufacturing or painting work environment is poor. In addition, in order to prevent air pollution, regulations on volatile organic compounds (VOCs) are gradually strengthened, and thus, researches are being actively conducted to develop environmentally friendly PCM paints.

For example, Korean Patent Registration No. 10-1257076 is a solvent-free agent that does not use volatile organic compounds (VOC), including a binder having a polyether-imide molecular structure and an oligomer having a polyester-imide molecular structure conjugate. Type PCM paint compositions are disclosed. However, the coating composition has a limitation in that the basic physical properties required for the coating composition, such as corrosion resistance and adhesion, are poor, so there is a continuing demand for a coating composition for PCM that is eco-friendly and can maintain basic properties of the coating composition. .

The present invention provides an eco-friendly water-soluble coating composition for PCM and a PCM steel sheet to which the same is excellent in flexibility, hardness, gloss and weather resistance.

The present invention provides a water-soluble PCM coating composition comprising a polyester resin and a melamine resin.

In addition, the present invention provides a steel sheet and a coating layer formed on the surface of the steel sheet, wherein the coating layer is a PCM steel sheet, which is a cured product of the aforementioned water-soluble PCM coating composition.

The present invention provides a coating composition for PCM excellent in flexibility, hardness, gloss and weather resistance. The coating composition for PCM according to the present invention can secure environment-friendliness by reducing the content of volatile organic compounds by using water as a solvent instead of an organic solvent. The coating composition for PCM according to the present invention can be applied to a steel plate (for example, a steel plate for a building material), and can be used as a top coat. The PCM steel sheet to which the coating composition for PCM according to the present invention is applied has excellent gloss and weather resistance.

Hereinafter, the present invention will be described in detail. However, it is not limited only by the following content, and each component may be variously modified or selectively used as necessary. Therefore, it is to be understood as including all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

<Paint composition>

The water-soluble PCM coating composition according to the present invention includes a polyester resin and a melamine resin. The paint composition of the present invention may further include a neutralizing agent, an extender pigment, a colored pigment, a solvent, and an additive commonly used in the paint field, if necessary.

Polyester resin

The coating composition according to the present invention contains a polyester resin as the main resin. The polyester resin reacts with the curing agent to form a coating film, gives gloss, and secures the basic physical properties of the coating film, corrosion resistance, processability, chemical resistance, hardness and adhesion.

The polyester resin may be prepared by polymerizing an alcohol monomer and an acid monomer in a solvent.

Examples of the alcohol monomers include ethylene glycol, propylene glycol, 1,2-butylene glycol, neopentyl glycol, and 1,6-hexanediol ( 1,6-Hexanediol), trimethylol propane, glycerol (Glycerol), one selected from the group consisting of, or a mixture thereof.

The alcohol monomer may be included in an amount of 20 to 45% by weight based on the total weight of the polyester resin composition.

The acid monomers include Isophthalic acid, Phthalic anhydride, Adipic acid, Sebacic acid, succinic acid, terephthalic acid, and trimellitic anhydride. (Trimellitic anhydride), tricarboxylic acid anhydride, benzenetricarboxylic acid anhydride, naphthalene tricarboxylic acid anhydride, or one selected from the group consisting of Mixtures and the like can be used.

The acid monomer may be included in an amount of 30 to 55% by weight based on the total weight of the polyester resin composition.

Examples of the solvent include aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, and ethyl propyl ketone, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate , Ethylethoxypropionate and the like may be used at least one selected from ester solvents, for example, butyl cellosolve, diethylene glycol monobutyl ether, propylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene Hydrophilic solvents, such as glycol n-butyl ether, can be used.

The solvent may be included in an amount of 10 to 30% by weight based on the total weight of the polyester resin composition.

The method for preparing the polyester resin is not particularly limited, and may be prepared by a method known in the art. For example, after adding an alcohol monomer and an acid monomer to a reactor, the temperature is gradually raised to 230° C. to react. When the acid value reaches a predetermined value (eg, 5 mgKOH/g or less), the reactor is cooled to 160° C. or less, and anhydrous acid is added to adjust the acid value to a predetermined range (eg, 15 to 25 mgKOH/g). After completion of the reaction, it can be diluted with a solvent to obtain a polyester resin capable of water solubility.

The number average molecular weight of the polyester resin is 500 to 8,000 g/mol, for example 1,000 to 5,000 g/mol, the hydroxyl value is 20 to 150 mgKOH/g, for example 30 to 80 mgKOH/g, and the acid value is 10 to 30 mgKOH/g, for example 15 to 25 mgKOH/g, and the glass transition temperature may be 0 to 25°C, for example 5 to 15°C. When the range of the number average molecular weight, hydroxyl value, acid value, and glass transition temperature of the polyester resin satisfies the above ranges, the formed coating film may exhibit excellent corrosion resistance, weather resistance, and hardness.

The content of the polyester resin is not particularly limited, and may be 15 to 65% by weight, for example, 25 to 50% by weight based on the total weight of the paint composition. When the content of the polyester resin falls within the above-described range, the basic physical properties of the coating film are good, excellent corrosion resistance, chemical resistance, and appearance characteristics may be expressed, and adhesion to other substrate layers may be improved.

Melamine resin

In the coating composition according to the present invention, the melamine resin serves as a curing agent (crosslinking agent) for curing the aforementioned polyester resin to form a stable coating film.

The kind of melamine resin usable in the present invention is not particularly limited, but, for example, a methoxy melamine resin, a butoxy melamine resin, an imino melamine resin, a butoxy/methoxy mixed melamine resin, etc. may be used.

The methoxy melamine resins include CYMEL-303, CYMEL-327, CYMEL-370 (CYTEC), BE-370, BE-3717 (BIP), RESIMINE AQ-717, RESIMINE AQ-730, RESIMINE AQ-747, RESIMINE AQ-7550 (SOLUTIA), butoxy melamine resin: RESIMINE-750, RESIMINE-7512 (SOLUTIA), BE-630, BE-692 (BIP), imino melamine resin: CYMEL-325, CYMEL -327, CYMEL-328 (CYTEC), butoxy/methoxy mixed resin: CYMEL-254, CYMEL-235, CYMEL-1168, CYMEL-1156, CYMEL-1170 (CYTEC), RESIMINE-751, RESIMINE- 755 (SOLUTIA) and LUWIPAL 072 (BASF).

For example, the melamine resin may include a methoxy melamine resin and a butoxy/methoxy mixed melamine resin. When a methoxy melamine resin and a butoxy/methoxy mixed melamine resin are used in combination, the degree of curing and flexibility of the coating film can be effectively improved.

The number average molecular weight of the methoxy melamine resin is 200 to 600 g/mol, for example, 300 to 450 g/mol, the viscosity (based on 23° C.) is 3,000 to 6,000 mPas, for example 4,000 to 5,000 mPas, and the solid content is It may be 60 to 100%, for example 80 to 100%. In addition, the number average molecular weight of the butoxy/methoxy mixed melamine resin is 650 to 1,500 g/mol, for example 850 to 1,100 g/mol, and the viscosity (based on 23° C.) is 4,000 to 7,000 mPas, for example 5,000 to 6,000 mPas, the solid content may be 60 to 90%, for example 80 to 90%. When the number average molecular weight, viscosity, and solid content of the methoxy melamine resin and the butoxy/methoxy mixed melamine resin satisfy the above-described ranges, the degree of curing is high and long-term corrosion resistance and adhesion may be improved.

The mixing ratio of the methoxy melamine resin and the butoxy/methoxy mixed melamine resin is not particularly limited, but may be 90:10 to 60:40, for example, 80:20 to 70:30 by weight. When the methoxy melamine resin and the butoxy/methoxy mixed melamine resin are mixed in the above-described blending ratio, the degree of curing and flexibility of the coating film can be effectively improved.

The content of the melamine resin is not particularly limited, and may be 1 to 25% by weight, for example 3 to 15% by weight, based on the total weight of the coating composition. When the content of the melamine resin is less than 1% by weight, solvent resistance and hardness may be deteriorated, and when it exceeds 25% by weight, the flexibility of the coating film and adhesion between the upper and lower coating films may decrease.

corrector

The coating composition according to the present invention may further include a neutralizing agent. The neutralizing agent serves to adjust the pH of the coating composition. The neutralizing agent serves to facilitate water solubility of the paint by adjusting the pH of the paint composition of the present invention in the range of 7.0 to 9.0, for example, 8.5 to 9.0.

As the neutralizing agent, one or more alkali components selected from caustic soda, soda ash, ammonia, potassium hydroxide and amine neutralizing agents may be used. As the amine neutralizing agent, any amine compound may be used without particular limitation. For example, methylamine, dimethylamine, trimethylamine, ethylamine, triethylamine, methanolamine, dimethanolamine, trimethanolamine, diethanolamine, Triethanolamine, diethylethanolamine, dimethylethanolamine, dimethylpropanolamine, phenyldiethanolamine, triisopropylamine, tributylamine, ammonia, or a mixture thereof.

The content of the neutralizing agent is not particularly limited, and may be 0.3 to 3% by weight, for example, 0.5 to 1.5% by weight based on the total weight of the coating composition. When the content of the neutralizing agent satisfies the above-described range, the pH of the coating composition can be effectively adjusted.

Extender pigment

The paint composition according to the present invention may further include an extender pigment. The extender pigment fills the pores in the coating film, complements the formation of the coating film, and plays a role of imparting rusting or mechanical properties to the coating film. Therefore, when the extender pigment is included, a good coating film appearance can be obtained, and hardness, impact resistance, and rust prevention properties can be improved.

As the extender pigments, those commonly used in paint compositions may be used without limitation, examples of which include calcium carbonate, clay, talc, magnesium silicate, kaolin, mica, silica, aluminum silicate, aluminum hydroxide, barium sulfate, etc. , The aforementioned ingredients may be used alone or two or more types may be used in combination. For example, the extender pigment may include silica.

The content of the extender pigment is not particularly limited, and may be 1 to 15% by weight, for example, 1 to 10% by weight based on the total weight of the paint composition. When the content of the extender pigment satisfies the above-described range, mechanical properties of the coating film may be improved.

Colored pigments

The paint composition according to the present invention may further include a conventional colored pigment used in the field of paint compositions within a range that does not impair the effect of the present invention. Colored pigments can be used to express a desired color (color) in the paint or to increase the strength or gloss of the coating film.

As the colored pigment, organic pigments, inorganic pigments, metallic pigments, aluminum-paste, pearl, and the like may be used without limitation, and these may be used alone or in combination of two or more. Non-limiting examples of the color pigments that can be used include azo-based, phthalocyanine-based, iron oxide-based, cobalt-based, carbonate-based, sulfate-based, silicate-based, chromate-based pigments, and the like, such as titanium dioxide, zinc oxide, bismuth vanadium. Date, cyanine green, carbon black, iron oxide, sulfur iron oxide, navy blue, cyanine blue, and mixtures of two or more thereof. For example, the colored pigment may include titanium dioxide and chromium yellow.

The content of the colored pigment is not particularly limited, and may be 5 to 40% by weight, for example, 10 to 35% by weight based on the total weight of the paint composition. When the content of the colored pigment satisfies the above-described range, the color expression of the coating film is excellent, and mechanical properties, impact resistance, and adhesion of the coating film may be improved.

solvent

The coating composition according to the present invention may further include a solvent. The coating composition according to the present invention is water-soluble, and most of the solvent may be composed of water, and water is used as the main solvent to provide an eco-friendly water-soluble paint. Deionized water or pure water may be used as water. The solvent may further include an organic solvent together with water.

The organic solvent has excellent solubility and stability, and can be used without special restrictions as long as it does not interfere with the main reaction.For example, an aromatic hydrocarbon-based solvent, an ester-based solvent, an ether-based solvent, an alcohol-based solvent or a mixture thereof can be used. I can. Non-limiting examples of usable organic solvents include cyclohexanone, xylene, toluene, cellosolve acetate, methyl ethyl ketone, dibasic ester, propylene glycol methyl ether acetate, n-butyl acetate, propylene glycol monomethyl acetate, 3 -Methoxy butyl acetate, ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether, ethylene glycol monohexyl ether, ethanol, isopropanol, n-butanol, amyl alcohol, butyl carbitol, Paraffin oil or a mixed solvent thereof, and hydrophilic solvents such as butyl cellosolve, diethylene glycol monobutyl ether, propylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-butyl ether, etc. I can.

In the present invention, the content of the solvent may be a residual amount that satisfies the total weight of the coating composition, and may be, for example, 1 to 50% by weight based on the total weight of the coating composition. When the content of the solvent falls within the above-described range, workability is improved and excellent physical properties of the coating film can be exhibited.

additive

The paint composition according to the present invention may further include conventional additives used in the paint composition field within a range that does not impair the effect of the invention.

Non-limiting examples of additives that can be used include dispersants, leveling agents, adhesion promoters, light stabilizers, surface modifiers, antifoaming agents, surfactants, softeners, thickeners, weathering additives, drying agents, appearance modifiers, moisture absorbents, matting agents, coupling agents, sedimentation Inhibitors, waxes, curing accelerators, or mixtures of two or more thereof.

The dispersant plays a role of dispersing each material constituting the composition and preventing re-aggregation by maintaining a distance to express the uniform physical properties of the coating film. As the dispersant, conventional ones known in the art may be used. For example, a high molecular weight block copolymer type dispersant may be used.

The anti-settling agent serves to prevent the settling of materials so that the coating film has a uniform property, and conventional ones known in the art may be used without limitation. For example, phosphate epoxy clock, silica, and clay type anti-settling agents may be used.

The antifoaming agent serves to enhance the appearance of the coating film by suppressing air bubbles generated during coating. For example, a silicone-based or non-silicone-based antifoaming agent may be used, and for example, a polysiloxane type antifoaming agent may be used.

The curing accelerator serves to improve the density of the coating film by accelerating the curing of the polyester resin and the melamine resin. As a curing accelerator that can be used, there may be a sulfonic acid compound, and for example, an amine or a sulfonic acid compound shielded with an epoxy resin may be used as a material that can be dissociated by heat. Non-limiting examples include P-toluene sulfonic acid such as NACURE 2107, NACURE 2500, NACURE 2547, NACURE 1323, NACURE 1419, NACURE 1557, Dinoyl naphthalene sulfonic acid such as NACURE 1953, NACURE 3483, NACURE 3327, NACURE 155, NACURE 3525 Dodecyl benzene disulfonic acid, such as dinonyl naphthalene disulfonic acid, NACURE 5225, NACURE 5414, etc., can be used.

The additive may be appropriately added within the content range known in the art, and for example, may be included in an amount of 0.1 to 10% by weight based on the total weight of the coating composition. When the content of the additive is within the above-described range, the appearance and hardness of the coating film may be improved.

The coating composition of the present invention may be prepared according to a conventional method known in the art, for example, after constituting each of the polyester resin, melamine resin, neutralizing agent, extender pigment, colored pigment, solvent and additive of the above-described composition, It can be prepared by mixing them.

<PCM steel plate>

The present invention provides a PCM steel sheet having a coating layer formed by using the above-described coating composition.

The PCM steel sheet includes a steel sheet and one or more coating layers formed on the surface of the steel sheet, and at least one of the one or more coating layers includes a coating layer formed by coating and curing the above-described PCM coating composition. . For example, the coating layer formed by applying the coating composition for PCM according to the present invention may be a top coating layer.

As the steel plate, a metal plate used in the art may be used without limitation. Non-limiting examples include zinc hot-dipping steel (GI), electro-zinc steel (EGI), hot-dip galvanized steel sheet, alloyed hot-dip galvanized steel sheet, electro-galvanized steel sheet, hot-dip aluminum-zinc alloyed steel sheet, and aluminum sheet. have.

The top coat layer formed on the steel sheet may have a dry coat thickness of 10 to 20 μm, for example, and the bottom coat layer may have a dry coat thickness of 3 to 7 μm, for example, 5 μm. When the thickness of the coating layer falls within the above-described range, concealment is ensured and defects in the coating layer can be minimized.

The PCM steel sheet according to the present invention may be manufactured according to a conventional method in the art, and for example, may be composed of a step of coating and drying the above-described PCM coating composition on a metal plate as a substrate.

As a coating method of the PCM coating composition, a conventional coating method known in the art can be applied, for example, curtain coating, roll coating, immersion coating, bar coating, and spray coating. The firing conditions can be appropriately changed according to conditions such as the width and thickness of the firing metal plate, and line speed, and for example, it may be performed for 35 to 40 seconds under the condition that the peak metal temperature (PMT) is 190 to 230°C. If necessary, the metal plate may be pretreated with a non-chromate compound before painting.

Since the PCM steel sheet manufactured as described above exhibits excellent gloss and weather resistance, it can be used for building materials.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are only intended to aid understanding of the present invention, and the scope of the present invention is not limited to the examples in any sense.

[Example 1-9]

According to the composition shown in Table 1 below, a polyester resin, a melamine resin, a neutralizing agent, an extender pigment, a colored pigment, a solvent, and an additive were mixed to prepare a coating composition of Example 1-9. In the polyester resin, an alcohol monomer and an acid monomer are added to the reactor, and the temperature is gradually raised to 230° C. to react. When the acid value reaches 3 mgKOH/g, the reactor is cooled to 160° C. or less, and anhydrous acid is added to the acid value. Was prepared by adjusting to 20 mgKOH/g. After completion of the reaction, a polyester resin water-soluble by diluting with propylene glycol n-propyl ether was used. The unit of use of each component according to Table 1 below is% by weight.

[Comparative Example 1-3]

According to the composition shown in Table 2 below, a polyester resin, a melamine resin, a neutralizing agent, an extender pigment, a colored pigment, a solvent, and an additive were mixed to prepare a coating composition of Comparative Example 1-3. As the polyester resin, a resin prepared in the same manner as in Example 1-9 was used.

The unit of use of each component according to Table 2 below is% by weight.

Polyester resin 1: number average molecular weight 2,462 g/mol, hydroxyl value 59.1 mgKOH/g, acid value 20 mgKOH/g, glass transition temperature 5 ℃

Polyester resin 2: number average molecular weight 3,023 g/mol, hydroxyl value 50.4 mgKOH/g, acid value 20 mgKOH/g, glass transition temperature 10.1 ℃

Polyester resin 3: number average molecular weight 2,107 g/mol, hydroxyl value 52.7 mgKOH/g, acid value 25 mgKOH/g, glass transition temperature 25 ℃

Polyester resin 4: number average molecular weight 2,421 g/mol, hydroxyl value 65.3 mgKOH/g, acid value 15 mgKOH/g, glass transition temperature 1.2 ℃

Polyester resin 5: number average molecular weight 2,524 g/mol, hydroxyl value 49.9 mgKOH/g, acid value 35 mgKOH/g, glass transition temperature 5.7 ℃

Polyester resin 6: number average molecular weight 2,408 g/mol, hydroxyl value 67.1 mgKOH/g, acid value 7 mgKOH/g, glass transition temperature 1.1 ℃

Polyester resin 7: number average molecular weight 2,096 g/mol, hydroxyl value 54.3 mgKOH/g, acid value 20 mgKOH/g, glass transition temperature -7.5 ℃

Melamine resin 1: Methoxy melamine resin (CYMEL-303, CYTEC, number average molecular weight 350 g/mol, viscosity (at 23 ℃) 4,000 mPas, solid content 90%)

Melamine resin 2: Butoxy/methoxy mixed melamine resin (LUWIPAL 072, BASF company, number average molecular weight 1,000 g/mol, viscosity (at 23 ℃) 6,000 mPas, solid content 80%)

Melamine resin 3: Butoxy/methoxy mixed melamine resin (number average molecular weight 2,500 g/mol, viscosity (at 23 ℃) 2,000 mPas, solid content 83%)

Neutralizing agent: dimethylethanolamine

Additive 1: Dispersant (DISPERSE 752W, TEGO company)

Additive 2: Dispersant (NUOSPERSE W-33, ELEMENTIS)

Additive 3: Wax (CHEMIPEARL W-401, MITSUI CHEMICALS)

Additive 4: Anti-settling agent (CVC00817, KCC company)

Additive 5: Antifoam (ST2400, BASF)

Additive 6: Hardening accelerator (Nacure-X155, KING INDUSTRIES, INC)

Solvent 1: deionized water

Solvent 2: Hydrocarbon

Solvent 3: Butyl Carbitol

Solvent 4: propylene glycol N-propyl ether

[Experimental Example-Evaluation of Physical Properties]

After measuring the physical properties of the coating composition prepared according to Examples 1-9 and Comparative Examples 1-3 as follows, the results are shown in Tables 3 and 4 below.

Specimen preparation

After coating the galvanized steel sheet with a water-soluble undercoat composition to have a undercoat thickness of 5 µm, and then coating the topcoat with a coating composition prepared according to each Example and Comparative Example to have a top coat thickness of 15 µm thereon, A specimen was prepared by curing at 224 to 232 °C based on a peak metal temperature (PMT).

Polish

It was measured at 60 degree gloss using a polisher.

Excellent: 80% or more

Good: 70% or more and less than 80%

Insufficient: 50% or more and less than 70%

Defect: less than 50%

Flexibility

The tape adhesion degree was evaluated by processing 2T at room temperature.

Excellent: No peeling

Good: less than 20% peeling

Insufficient: more than 20% and less than 50% peeling

Defect: Excess 50% peeling

Solvent resistance

Methyl ethyl ketone (MEK) was buried in gauze and the number of round trips under a 1KG load was measured.

Excellent: more than 100 times

Good: 80 or more, less than 100

Insufficient: 50 or more, less than 80

Defect: less than 50 times

Hardness

The traces generated by drawing five lines with Mitsubishi uni pencil 2H were evaluated.

Excellent: No trace

Good: 1 to 2 lines trace

Insufficient: 3 to 4 lines trace

Poor: There is a trace of more than 5 lines

Weather resistance

According to ASTM A 4587 standard, the gloss retention rate was evaluated after 2,000 hours evaluation with Q-LAB's QUV-A TEST equipment.

Excellent: More than 80% gloss retention

Good: more than 65% gloss retention, less than 80%

Insufficient: Gloss retention rate of 50% or more, less than 65%

Poor: Less than 50% gloss retention

Claims (7)

In the coating composition containing a polyester resin and a melamine resin,
The polyester resin has a number average molecular weight of 500 to 8,000 g/mol, a hydroxyl value of 20 to 150 mgKOH/g, an acid value of 10 to 30 mgKOH/g, and a glass transition temperature of 0 to 25°C. The coating composition according to claim 1, wherein the melamine resin comprises a methoxy melamine resin and a butoxy/methoxy mixed melamine resin. The method of claim 2, wherein the number average molecular weight of the methoxy melamine resin is 200 to 600 g/mol, the viscosity (based on 23°C) is 3,000 to 6,000 mPas, and the number average molecular weight of the butoxy/methoxy mixed melamine resin is 650 to 1,500 g/mol, and a viscosity (based on 23° C.) of 4,000 to 7,000 mPas. The coating composition according to claim 2, wherein the blending ratio of the methoxy melamine resin and the butoxy/methoxy mixed melamine resin is 90:10 to 60:40 by weight. The coating composition according to claim 1, further comprising 0.3 to 3% by weight of a neutralizing agent which is an amine compound. The coating composition according to claim 1, comprising 15 to 65% by weight of a polyester resin and 1 to 25% by weight of a melamine resin based on the total weight of the coating composition. A PCM steel sheet comprising a steel sheet and at least one coating layer formed on the surface of the steel sheet, wherein at least one of the coating layers is formed from the coating composition according to any one of claims 1 to 6.