JP2011213809A - Coating composition and method of coating the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition which has good storage stability, does not cause unstable spray when minute droplets are sprayed by pressurization through electric drive, achieves fast drying, obtains a coated article desirable in quality and free from cissing and bleeding, and is excellent in development of colors.SOLUTION: In the coating composition including a pigment, a resin component, a solvent, and water and having a viscosity at 20°C of 30 mPa s or less and surface tension of 21-34 mN/m, the resin component accounts for 1-20 wt.% of the coating composition and a ratio of the solvent in the coating composition is 5-40 wt.%. The coating composition includes one or more solvents (a) as the solvent, and the solvent (a) accounts for 5-100 wt.% of the total solvents. The solvent (a): a contact angle thereof at 20°C is 20 ° or less 10 seconds after being dropped onto a plastic substrate having a contact angle with water at 20°C of 85-95 °, and a contact angle at 20°C is 70 ° or less 10 seconds after a droplet of a 10 wt.% aqueous solution of the solvent is dropped onto the plastic substrate.

Description

  The present invention relates to a water-based coating composition and a method for applying the same, and more particularly, when an electric drive is applied and fine droplets are jetted and applied, unstable jetting does not occur, drying is fast, and repellency and blurring occur. The present invention relates to a coating composition that is excellent in quality and has a good color expression, and a coating method thereof.

  Conventionally, many coating compositions using various solvents have been proposed as coating compositions comprising a pigment, a binder resin, a pigment dispersant, a solvent, and water.

  In the case of using a conventional coating composition to produce a painted product with fine droplets, unstable spraying may occur, resulting in an unfavorable quality product, or using such a coating composition. In some cases, the color development is not always sufficient even when the is manufactured.

  As a factor causing the above unstable jetting, generally, the selection of the solvent in the composition causes the drying of the fine droplets to become too fast, and the drying progresses before the jetting, so that it adheres to the discharge machine. There is a method of adding a high boiling point solvent to prevent this (for example, Patent Document 1).

  On the other hand, Patent Document 2 adopts a method of adding a silicone acrylic resin as a method of improving repelling and bleeding, but it is not provided for an aqueous composition.

Japanese Patent No. 3050049 JP-A-10-251573

  The object of the present invention is to solve the above-mentioned problems, and the storage stability of the coating composition is good, so that unstable injection does not occur when fine droplets are injected by pressurization by electric drive. An object of the present invention is to provide a coating composition that is fast in drying, free of repellency and bleeding, is excellent in quality, and excellent in color development, and a method for applying the same.

  As a result of intensive investigations to achieve the above-mentioned object, the present inventors have elucidated the drying process of the fine droplets after coating, and the drying and spreading by the solvent in the composition and by the environment after coating. I found out that it can be adjusted.

According to the present invention, in a coating composition containing a pigment, a resin component, a solvent, water, a viscosity at 20 ° C. of 30 mPa · s or less, and a surface tension of 21 to 34 mN / m,
The resin component is 1 to 20% by weight in the coating composition;
The solvent ratio in the coating composition is 5 to 40% by weight, the solvent contains one or more of the following solvents (a), and the solvent (a) contains 5 to 100% by weight in all the solvents. Coating composition characterized by:
Solvent (a)
The contact angle at 20 ° C. after 10 seconds when dropped on a plastic substrate having a contact angle with water at 20 ° C. of 85 ° to 95 ° is 20 ° or less, and
There is provided a solvent having a contact angle at 20 ° C. of 70 ° or less after 10 seconds when a 10 wt% aqueous solution of the solvent is dropped on the plastic substrate.

  Further, in the method of applying the coating composition according to the present invention, the coating composition is pressurized by electric drive, and the substrate is applied by discharging droplets in a non-contact manner so that the volume of the droplet is 2 nl or less. A method for applying a coating composition is provided.

  By using the coating composition of the present invention, it has good storage stability, does not cause unstable jetting when applying fine droplets, is fast in drying, has no repellency or blurring, and is a coated product preferable in terms of quality. In addition, excellent color expression can be obtained.

  Below, the coating composition of this invention is demonstrated concretely.

  In the coating composition containing the pigment, resin component, solvent, and water of the present invention, the viscosity at 20 ° C. is 30 mPa · s or less, the surface tension is 21 to 34 mN / m, and the resin component is 1 to 3 in the coating composition. It is essential that the solvent content is 20% by weight and the solvent ratio in the coating composition is 5 to 40% by weight. If the resin component is less than 1% by weight, adhesion to the substrate, water resistance, and alcohol resistance are liable to deteriorate, and a good article cannot be obtained. On the other hand, if it exceeds 20% by weight, ejection failure and storage stability are liable to occur, and a good article cannot be obtained. When the viscosity of the coating composition exceeds 30 mPa · s, ejection failure occurs. Further, when the surface tension is less than 21 mN / m or exceeds 34 mN / m, ejection failure occurs.

  In the coating composition of the present invention, the contact angle after 10 seconds when dropped onto a plastic substrate having a contact angle with water at 20 ° C. of 85 ° to 95 ° is 20 ° or less and 10% by weight One or more of the solvents (a) having a contact angle at 20 ° C. of 70 ° or less after 10 seconds when the droplets of the solvent aqueous solution were dropped on the plastic substrate were used. It is essential to contain 100% by mass.

  Examples of the plastic substrate having a contact angle with water at 20 ° C. of 85 ° to 95 ° include plastics mainly composed of polyethylene terephthalate (PET), polycarbonate, vinyl chloride, polypropylene, polyurethane, epoxy, acrylic, and the like. Products, and PET, polycarbonate, vinyl chloride, and polyurethane are generally the main components and are preferred. Examples of the substrate shape include films, sheets, and molded products.

There is no restriction | limiting in particular as a pigment used for the coating composition of this invention, All the pigments used for the normal coating composition can be used. For example,
Pigment Yellow 12, 13, 14, 17, 20, 24, 31, 42, 53, 55, 74, 83, 86, 93, 109, 110, 117, 125, 128, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 155, 166, 168, 180, 181, 184, 185,
Pigment Orange 16, 36, 38, 43, 51, 55, 59, 61, 64, 65, 71,
Pigment Red 9, 48, 49, 52, 53, 57, 97, 101, 122, 123, 149, 168, 177, 180, 192, 202, 206, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 244, 254,
Pigment violet 19, 23, 29, 30, 32, 37, 40, 50,
Pigment Blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 22, 30, 60, 64, 80,
Pigment Green 7, 36,
Pigment brown 23, 25, 26,
Pigment Black 1, 7, 26, 27, 28,
Examples thereof include titanium oxide, iron oxide, ultramarine, yellow lead, zinc sulfide, cobalt blue, barium sulfate, and calcium carbonate. Although the compounding quantity of a pigment can be arbitrarily determined with the kind etc. of pigment to be used, Preferably it is 0.1-15 mass% of a coating composition, More preferably, it is 0.5-10 mass%. The pigment preferably has an average particle size (d50) of 30 to 300 nm in the coating composition. When the average particle diameter is larger than 300 nm, it tends to settle, so that the storage stability tends to decrease. On the other hand, an average particle diameter of less than 30 nm is not preferable because coloring power is insufficient or reaggregation tends to occur.

  There is no restriction | limiting in particular as a resin component used for the coating composition of this invention, All can be used for resin used for the normal coating composition. Examples thereof include amino resins such as acrylic resins, urethane resins, polyester resins, epoxy resins, melamine, and benzoguanamine, water-soluble resins such as polyamide resins and vinyl acetate copolymer resins, dispersions, and emulsions.

There is no restriction | limiting in particular as said solvent, All the solvents used for a normal coating composition can be used, for example,
Ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, ethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol monobutyl ether, Ethylene glycol ethers such as triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether;
Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol diethyl ether, etc. Propylene glycol ethers;
Alkanediols such as 1,2-hexanediol;
Alcohols such as acetyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol;
heterocyclic compounds such as γ-butyrolactone and γ-valerolactone;
Examples thereof include nitrogen-containing compounds such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, and mixtures thereof.

  The solvent ratio in the coating composition is essential to be 5 to 40% by weight, preferably 10 to 30% by weight. When the solvent ratio is less than 5% by weight, the wettability with the base material is deteriorated, and a good coating cannot be obtained. When the solvent ratio exceeds 40% by weight, drying is slowed, and repelling and bleeding occur. It becomes easy.

  As said solvent, the contact angle of 10 seconds when dripped on the plastic base material whose water contact angle at 20 degreeC is 85 degrees-95 degrees is 20 degrees or less, and this solvent aqueous solution of 10 weight% It is essential to contain at least one solvent (a) having a contact angle at 20 ° C of 70 ° or less after 10 seconds when the above droplet is dropped onto the plastic substrate. As the solvent (a), water-soluble solvents such as (poly) alkylene glycol derivatives and alkanediols can be widely used. Among them, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol diethyl ether, triethylene glycol monobutyl ether, propylene glycol Dimethyl ether and mixtures thereof are preferred.

  The solvent (a) has a contact angle of 20 ° or less after 10 seconds when dropped on a plastic substrate having a contact angle with water at 20 ° C. of 85 ° to 95 °, and 10% by weight. It is essential that the contact angle after 10 seconds when a solvent aqueous solution droplet is dropped on the plastic substrate is 70 ° or less. If the contact angle after 10 seconds when dropped on a plastic substrate having a contact angle with water of 85 ° to 95 ° exceeds 20 °, the wettability with the substrate deteriorates and a good coating is obtained. It becomes impossible. Further, when the contact angle after 10 seconds when a 10% by weight droplet of the solvent aqueous solution is dropped on the plastic substrate is more than 70 °, the wettability with the substrate is deteriorated, and a good coated object is obtained. Cannot be obtained.

  It is essential that the solvent (a) is contained in the total amount of 5 to 100% by weight, and preferably 30 to 100% by weight. When the solvent (a) is less than 5% by weight in the total solvent, the wettability with the substrate is deteriorated.

  Further, when the solvent (a) is ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether or a mixture thereof in an amount of 10% by weight or more in the total solvent, the solvent aqueous solution droplets of 0.5 to 1 are used. From the viewpoint of the balance between the wettability with the substrate and the drying time, 5 nl is dropped onto the plastic substrate and the contact angle at 20 ° C. with the plastic substrate is 10 ° or less within 2 seconds. More preferred.

  As the coating composition of the present invention, when applied to the plastic substrate, the volume of 0.5 to 1.5 nl droplets is preferably 60% or less within 2 seconds, more preferably 50% or less. Is to become. If the volume of the droplets exceeds 60% within 2 seconds, drying is slow, causing repelling and bleeding, making it difficult to obtain a good object to be coated.

  Furthermore, as a coating composition of the present invention, when applied to the plastic substrate, the droplet diameter of 0.5 to 1.5 nl is preferably 1.2 times or more within 2 seconds, more preferably. Is 1.25 times or more and 1.5 times or less. If the droplet diameter is less than 1.2 times within 2 seconds, drying is slow, causing repelling and bleeding, making it difficult to obtain a good coating.

  Furthermore, the coating composition of the present invention preferably has a (height) / (droplet diameter) of a droplet of 0.5 to 1.5 nl of 0.3 or less when applied to the plastic substrate. More preferably, it is 0.25 or less. If it exceeds 0.3, the color developability is poor and it becomes difficult to obtain a good article to be coated.

  Further, when the coating composition of the present invention is applied to the plastic substrate, the surface area of the 0.5 to 1.5 nl droplet is preferably 1.4 times or more within 2 seconds, more preferably. The better is 1.5 times or more and 2 times or less. If the surface area of the droplet is less than 1.5 times within 2 seconds, drying is slow, causing repelling and bleeding, making it difficult to obtain a good coating.

  Although there is no restriction | limiting in particular as said resin component of the coating composition of this invention, Polycarbonate group containing polyurethane resin is contained in this resin component 10 to 95weight%, or styrene and methyl methacrylate are 30 ~ in this resin component. It is preferable to contain 50 to 90% by weight of an acrylic polymer containing 90% by weight. If the polycarbonate group-containing polyurethane resin is less than 10% by weight, the coating strength tends to be insufficient, so that the water resistance and alcohol resistance are liable to deteriorate, and a good coating cannot be obtained. If it exceeds 95% by weight, the gloss of the coating film tends to decrease, and a good article cannot be obtained. If styrene and methyl methacrylate are less than 30% by weight, the coating strength tends to be insufficient, so that the water resistance and alcohol resistance are liable to deteriorate, and a good article cannot be obtained. If it exceeds 90% by weight, aggregation tends to occur and a good coating composition cannot be obtained.

  As a coating method of the coating composition of the present invention, general coating methods such as spray coating, dip coating, spin coating, and dispenser can be applied, but pressure is applied by electric driving, and the volume of droplets is 2 nl or less, preferably 0. It is preferable from the viewpoints of coating properties and drying properties to use a coating method in which droplets are ejected in a non-contact manner so as to be 0.5 to 1.5 nl. When the volume of the droplet exceeds 2 nl, it becomes difficult to obtain sufficient drying properties and coating film performance of the coating composition.

  Moreover, it is preferable that the coating composition of this invention heats a base material so that it may become 35 degreeC or more. When the temperature of the substrate is less than 35 ° C., it is difficult to obtain sufficient color developability, and a good object to be coated cannot be obtained. When the temperature is too high, the coating composition may be thermally deteriorated, so the temperature is preferably 37 ° C to 45 ° C.

  Furthermore, it is preferable to apply a wind at a wind speed of 1 m / second or more to a substrate within 1 second immediately after applying the coating composition of the present invention. If the coating composition is applied and left for more than 1 second, it tends to bleed, which is not preferable. Further, when no wind is applied to the object to be coated or a wind of less than 1 m / second is applied, blocking is likely to occur, which is not preferable. Preferably, it is 2 m / second to 7 m / second.

  The coating composition of the present invention can be made of a general material as long as it has a size, thickness and shape suitable for coating as a substrate, and surface treatment or coating may be performed in advance. Among them, an iron plate, an aluminum plate, a stainless steel plate or a coated product thereof, a ceramic coating plate, and a resin sheet or molded body mainly composed of polyethylene terephthalate (PET), polycarbonate, or vinyl chloride resin are preferable. It is preferable because adhesion and gloss can be obtained.

  Hereinafter, the present invention will be described more specifically based on Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following examples and comparative examples, “parts” and “%” are based on weight unless otherwise specified.

  First, the raw materials shown in Table 1 were dispersed with a paint shaker for 15 hours using zirconia beads having a diameter of 0.5 mm to prepare a dispersion liquid containing a pigment. Similarly, the raw materials shown in Table 2 were dispersed for 24 hours with a paint shaker using zirconia beads having a diameter of 0.5 mm to prepare a dispersion liquid containing a pigment.

<Synthesis of polycarbonate group-containing urethane resin emulsion 1>
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer and nitrogen inlet tube, 157.0 parts of 1,6-hexanediol polycarbonate diol (average molecular weight 2000), 1.0 part of trimethylolpropane, 1, After charging 10.2 parts of 4-cyclohexanedimethanol, 10.5 parts of propionic acid, 0.001 part of dibutyltin dilaurate and 110.0 parts of methyl ethyl ketone and mixing them uniformly, 4,4′-methylenebis (cyclohexyl isocyanate) 82 0.0 part was added and it was made to react at 70 degreeC for 6 hours, and the methyl ethyl ketone solution of the carboxyl group-containing isocyanate group terminal prepolymer was obtained. After cooling the solution to 40 ° C. or lower, 7.5 parts of triethylamine was added, and a neutralization reaction was performed at 40 ° C. for 30 minutes.

  Next, the neutralized solution is cooled to 30 ° C. or lower, and 450.0 parts of water is gradually added using a disperse blade to emulsify and disperse the neutralized polycarbonate group-containing isocyanate group-terminated prepolymer. Obtained. Then, a polyamine aqueous solution prepared by dissolving 6.0 parts of 50% hydrazine aqueous solution and 1.2 parts of diethylenetriamine in 20.0 parts of water was added to the dispersion, reacted for 2 hours, and then depressurized at 30 ° C. under reduced pressure. Solvent was used to obtain a stable polycarbonate group-containing polyurethane resin emulsion 1 having a polycarbonate group-containing polyurethane resin content of 35%, a viscosity of 70 mPa · s, and an average particle diameter of 21 nm.

The following were used as pigments:
Carbon black (trade name: Special Black 550, manufactured by Degussa)
Copper phthalocyanine (trade name: Irgarite Blue 8700, manufactured by Ciba),
Quinoxalinedione (trade name: Hosta Palm Yellow H5G, manufactured by Clariant),
Dimethylquinacridone (trade name: Super Magenta RG, manufactured by DIC),
Titanium dioxide (trade name: TR92, manufactured by Huntsman).

(Examples 1-113 and Comparative Examples 1-7)
Test paints of Examples 1-113 and Comparative Examples 1-7 were prepared as shown in Tables 3-9.

<Synthesis of polycarbonate group-free urethane resin emulsion 2>
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer and nitrogen inlet tube, 157.0 parts of polyester diol (average molecular weight 2000) obtained from adipic acid and 1,6-hexanediol, trimethylolpropane 1 0.04 parts, 10.4-parts of 1,4-cyclohexanedimethanol, 10.5 parts of propionic acid, 0.001 part of dibutyltin dilaurate and 110.0 parts of methyl ethyl ketone were mixed and mixed, and then 4,4'- 82.0 parts of methylene bis (cyclohexyl isocyanate) was added and reacted at 70 ° C. for 6 hours to obtain a methyl ethyl ketone solution of carboxyl group-containing isocyanate group-terminated prepolymer. After cooling the solution to 40 ° C. or lower, 7.5 parts of triethylamine was added, and a neutralization reaction was performed at 40 ° C. for 30 minutes.

  Next, the neutralized solution is cooled to 30 ° C. or less, and 450.0 parts of water is gradually added using a disperse blade to emulsify and disperse the neutralized polycarbonate group-free isocyanate group-terminated prepolymer. Got. Then, a polyamine aqueous solution prepared by dissolving 6.0 parts of 50% hydrazine aqueous solution and 1.2 parts of diethylenetriamine in 20.0 parts of water was added to the dispersion, reacted for 2 hours, and then depressurized at 30 ° C. under reduced pressure. Solvent was used to obtain a stable polycarbonate group-free polyurethane resin emulsion 2 having a polycarbonate group-free polyurethane resin content of 35%, a viscosity of 60 mPa · s, and an average particle size of 25 nm.

<Synthesis of acrylic resin emulsion>
To a four-necked flask equipped with a stirrer, reflux condenser and thermometer, add 30 parts of water, 0.3 part of polyoxyethylene styryl phenyl ether sulfate ammonium salt and 1 part of polyoxyalkylene alkyl ether, and heat to 70 ° C. After adding 0.1 part of potassium persulfate, a mixture of 3 parts of butyl acrylate, 1 part of acrylic acid, 12 parts of styrene and 24 parts of methyl methacrylate was added dropwise, and then 30 parts of water was added and ammonia was added. The pH was adjusted to 9 with water. A good acrylic resin emulsion having an acrylic resin content of 40%, an average particle size of 75 nm, and Tg = 84 ° C. was obtained.

As deionized water and resin, urethane resin emulsion 1 obtained above, urethane resin emulsion 2, acrylic resin emulsion,
As a surface conditioner,
Polyether-modified silicone oil (trade name: 57ADDITIVE, manufactured by Toray Dow),
As a solution (the angles in parentheses below are the contact angle at 20 ° C. after 10 seconds when the contact angle with water at 20 ° C. is 89 ° and the contact angle with water is 10% by weight. And a contact angle at 20 ° C. after 10 seconds when a droplet of the solvent aqueous solution is dropped on the plastic substrate),
Ethylene glycol monobutyl ether (trade name: butyl glycol, manufactured by Nippon Emulsifier Co., Ltd., 6 °, 30 °),
Diethylene glycol monobutyl ether (trade name: Hisolv DB, manufactured by Toho Chemical Industries, 7 °, 44 °),
Diethylene glycol monoisobutyl ether (trade name: isobutyl diglycol, manufactured by Nippon Emulsifier Co., Ltd., 6 °, 38 °),
Triethylene glycol monobutyl ether (trade name: butoxy triglycol, manufactured by Dow Chemical Co., 12 °, 51 °),
Diethylene glycol methyl ethyl ether (trade name: methyl ethyl diglycol, manufactured by Nippon Emulsifier Co., 17 °, 73 °),
Diethylene glycol diethyl ether (trade name: Hisolv EDE, manufactured by Toho Chemical Industries, 7 °, 66 °),
Ethylene glycol (trade name: ethylene glycol B, manufactured by Mitsubishi Chemical Corporation, 62 °, 84 °),
Each of the coating compositions was prepared by adding a dispersion and stirring the dispersion.

  Next, various characteristics and performance evaluation were performed as follows. The results are shown in Tables 10 to 11.

[viscosity]
The viscosity of the coating composition at 20 ° C. was measured using a rheometer ARES manufactured by TA Instruments.

[surface tension]
The surface tension of the coating composition at 20 ° C. was measured using an automatic surface tension meter CBVP-Z manufactured by Kyowa Interface Science Co., Ltd.

[Average particle size]
The average particle size of the pigment of the coating composition was measured using a particle size distribution analyzer UPA manufactured by Microtrac.

[Coating equipment]
Application | coating of the coating composition was performed using the 3-axis marking apparatus by the glory electronics company.

[Droplet measurement]
The volume of the droplet, the diameter of the droplet, the height of the droplet, and the surface area of the droplet were measured using a CCD camera equipped with a 12 × zoom lens.

<Nozzle clogging>
When printing on the surface of the vinyl chloride sheet with a triaxial marking device, the head is allowed to stand for 15 minutes in the middle of printing, and then the number of nozzles that cannot discharge the composition to a predetermined position when printing is started again. Counted and evaluated according to the following criteria.
A: The number of nozzles that cannot be discharged to a predetermined position after being left for 15 minutes is 1/60 or less of the total number of nozzles,
A: The number of nozzles that cannot be discharged to a predetermined position after being left for 15 minutes is 2/60 or less of the total number of nozzles,
X: The number of nozzles that cannot be discharged to a predetermined position after being left for 15 minutes is more than 2/60 of the total number of nozzles

<Continuous discharge property>
A solid printing of 1 m × 4 m was performed on the surface of the vinyl chloride sheet using a 3-axis marking device manufactured by Eiko Denshi Co., Ltd., and evaluation was performed according to the following criteria based on the number of flight bends and omissions.
◎: No flying bends or missing
○: The total number of flight bends and omissions is 1 to 3,
Δ: The total number of flight bends and omissions is 4-6,
X: The total number of flight bends and omissions is 7 or more.

<Storage stability>
It was stored at 50 ° C. for 28 days and visually evaluated according to the following criteria.
A: No change
○: Slightly floating
X: Precipitation / separation occurs.

<Drying>
An image was printed on the surface of the vinyl chloride sheet with a triaxial marking device, and the printed material immediately after printing and after 30 seconds was touched with a finger, and evaluated according to the following criteria.
A: The coating composition does not adhere to the finger even immediately after printing.
○: The coating composition adheres to the finger immediately after printing, but does not adhere after 30 seconds.
X: The coating composition adheres to the finger even after 30 seconds.

<Repel>
Images were printed on the surface of the vinyl chloride sheet with a triaxial marking device, and the printed matter immediately after printing was visually evaluated according to the following criteria.
A: There is no repellency in the coating composition.
○: There is a slight repellency in the coating composition, but there is no practical problem.
X: The coating composition has repelling.

<Smear>
Images were printed on the surface of the vinyl chloride sheet with a triaxial marking device, and the printed matter immediately after printing was visually evaluated according to the following criteria.
A: The coating composition has no bleeding.
○: Slightly blurred coating composition, but practically no problem,
X: The coating composition has blur.

<Adhesion>
An image is printed on the surface of the vinyl chloride sheet with a triaxial marking device, and a tape of 24 mm width (registered trademark, manufactured by NICHIBAN) is adhered to the image portion, and then the tape is peeled off. evaluated.
A: No peeling,
○: Slight trace of peeling but practically no problem,
X: There is peeling.

<Water resistance>
An image was printed on the surface of the vinyl chloride sheet with a triaxial marking device, and the image was rubbed 10 times with gauze soaked with ion-exchanged water, and the appearance of the image was visually evaluated.
A: No trace of scratches,
○: Level of slight scratches but practically no problem
X: There are traces of scratches.

<Ethanol resistance>
An image was printed on the surface of the vinyl chloride sheet with a triaxial marking device, and the image was rubbed 10 times with gauze soaked with a 75% aqueous ethanol solution, and the appearance of the image was visually evaluated.
A: No trace of scratches,
○: Level of slight scratches but practically no problem
X: There are traces of scratches.

<Glossy>
The gloss of the printed material obtained by printing an image on the surface of the vinyl chloride sheet with a triaxial marking device was measured using a gloss meter VG 2000 manufactured by Nippon Denshoku Industries Co., Ltd.
A: Glossy,
○: slightly inferior gloss level but practically no problem,
X: No gloss.

<Color unevenness>
Printed materials obtained by printing images on various substrates with a triaxial marking device were visually evaluated according to the following criteria.
A: No color unevenness,
○: Slightly uneven color but practically no problem,
X: There is color unevenness.

<Color development>
The color difference ΔE was measured using a spectrophotometer COLOR-EYE3100 manufactured by Macbeth Co., Ltd., on a printed material obtained by printing images on various substrates using a triaxial marking device.
A: ΔE is within 1;
○: ΔE is within 3
X: ΔE exceeds 3.

<Blocking property>
Two printed materials on which images were printed on various substrates using a triaxial marking device were overlapped, and weights were placed so that a load of 1 kgf / cm ² was applied, and the degree of adhesion of the objects to be coated was determined after being left for 1 hour.
A: There is no bonded part at all,
○: A level where there is a part of adhesion but no problem in practical use.
X: Many parts adhere | attach and some coating films peel.

(Example 114)
Using Ramires PJ-1304NX manufactured by Muto Kogyo Co., Ltd., which uses the coating composition in Example 88 and pressurizes the surface of the vinyl chloride sheet by electric drive so that the volume of the liquid droplet is 2 nl or less. Except for the above, images were printed in the same manner as in Example 88, and various characteristics and performance evaluations were performed. The results are shown in Table 12.

(Example 115)
An image was printed in the same manner as in Example 88 except that the coating composition in Example 88 was used and the vinyl chloride sheet as a substrate was heated to 40 ° C., and various characteristics and performance evaluations were performed. The results are shown in Table 12.

(Example 116)
An image was printed in the same manner as in Example 88 except that the coating composition in Example 88 was used and dried on the substrate within 1 second after application by applying wind at a wind speed of 3 m / second. Performance evaluation was performed. The results are shown in Table 12.

(Examples 117 to 123)
Except that the coating composition in Example 88 was used and the base material was galvanized steel sheet, galvanized steel sheet coating, aluminum plate, stainless steel plate, ceramic building material, polyethylene terephthalate resin, polycarbonate resin, the same as Example 88 Images were printed and various characteristics and performance evaluations were made. The results are shown in Table 12.

(Example 124)
In Example 114, an image was printed in the same manner as in Example 114 except that the vinyl chloride sheet as the base material was heated to 40 ° C., and various characteristics and performance evaluations were performed. The results are shown in Table 12.

(Example 125)
In Example 114, images were printed in the same manner as in Example 114, except that the substrate was dried by applying wind at a wind speed of 3 m / sec within 1 second after application, and various characteristics and performance evaluation were performed. The results are shown in Table 12.

(Examples 126 to 132)
Using the coating composition in Example 88, the substrate is a galvanized steel sheet, a coated product of a galvanized steel sheet, an aluminum plate, a stainless steel plate, a ceramic building material, a polyethylene terephthalate resin, a polycarbonate resin, and the surface is pressurized by electric drive, An image was printed in the same manner as in Example 88, except that it was applied using Ramirez PJ-1304NX manufactured by Muto Kogyo Co., Ltd., which discharges the liquid droplets in a non-contact manner so that the volume of the liquid droplet is 2 nl or less. Performance evaluation was performed. The results are shown in Table 12.

(Example 133)
In Example 114, except that the vinyl chloride sheet as the base material was heated to 40 ° C. and dried by applying wind at a wind speed of 3 m / second to the base material within 1 second after coating. Images were printed and various characteristics and performance were evaluated. The results are shown in Table 12.

(Examples 134 to 140)
Using the coating composition in Example 88, the galvanized steel sheet as the base material, the coated galvanized steel sheet, the aluminum plate, the stainless steel plate, the ceramic building material, the polyethylene terephthalate resin, and the polycarbonate resin are heated to 40 ° C. and electrically driven. The images were printed in the same manner as in Example 88 except that Ramirez PJ-1304NX manufactured by Muto Kogyo Co., Ltd., which ejects droplets in a non-contact manner so that the volume of the droplets was 2 nl or less, and various types were printed. The characteristics and performance were evaluated. The results are shown in Table 12.

(Examples 141-147)
In Examples 126 to 132, images were printed in the same manner as in Examples 126 to 132, except that the substrate was dried by applying wind at a wind speed of 3 m / second to the substrate within 1 second after application, and various properties and performances were obtained. Evaluation was performed. The results are shown in Table 12.

(Examples 148 to 154)
In Examples 134 to 140, images were printed in the same manner as in Examples 134 to 140 except that the substrate was dried by applying wind at a wind speed of 3 m / sec to the substrate within 1 second after coating, and various properties and performances were obtained. Evaluation was performed. The results are shown in Table 12.

Claims (15)

In a coating composition containing a pigment, a resin component, a solvent, water, a viscosity at 20 ° C. of 30 mPa · s or less, and a surface tension of 21 to 34 mN / m,
The resin component is 1 to 20% by weight in the coating composition;
The solvent ratio in the coating composition is 5 to 40% by weight, the solvent contains one or more of the following solvents (a), and the solvent (a) contains 5 to 100% by weight in all the solvents. Coating composition characterized by:
Solvent (a)
The contact angle at 20 ° C. after 10 seconds when dropped on a plastic substrate having a contact angle with water at 20 ° C. of 85 ° to 95 ° is 20 ° or less, and
A solvent having a contact angle at 20 ° C. of 70 ° or less after 10 seconds when a 10% by weight aqueous solution of the solvent is dropped on the plastic substrate.   When the solvent (a) is used, a 0.5 to 1.5 nl droplet of the solvent aqueous solution of 10% by weight or more is dropped on the plastic substrate, and the contact angle with the plastic substrate at 20 ° C. is within 2 seconds The coating composition according to claim 1, which is a solvent that becomes 10 ° or less.   The coating composition according to claim 1 or 2, wherein the coating composition is applied to the plastic substrate, and the volume of a droplet of 0.5 to 1.5 nl is 60% or less within 2 seconds.   The coating composition according to any one of claims 1 to 3, wherein the coating composition is applied to the plastic substrate, and a droplet diameter of 0.5 to 1.5 nl is 1.2 times or more within 2 seconds. object.   The coating composition is applied to the plastic substrate, and the (height) / (droplet diameter) of a 0.5 to 1.5 nl droplet is 0.3 or less. The coating composition as described.   The coating according to any one of claims 1 to 5, wherein the coating composition is applied to the plastic substrate, and the surface area of a 0.5 to 1.5 nl droplet becomes 1.4 times or more within 2 seconds. Composition.   The coating composition according to any one of claims 1 to 6, wherein the resin component contains 10 to 95% by weight of a polycarbonate group-containing polyurethane resin, and the solvent further contains at least one glycol ether solvent. .   The coating composition according to any one of claims 1 to 7, wherein the resin component contains 50 to 90% by weight of an acrylic polymer containing 30 to 90% by weight of styrene and methyl methacrylate.   The coating composition according to any one of claims 1 to 8, wherein the coating composition is pressurized by electric driving, and droplets are ejected in a non-contact manner so that the volume of the droplets is 2 nl or less.   The coating composition according to claim 1, which is applied to a substrate heated to 35 ° C. or higher.   The coating composition according to any one of claims 1 to 10, wherein the coating composition is dried by applying air to a substrate within 1 second after application at a wind speed of 1 m / second or more.   The object to be coated is an iron plate, an aluminum plate, a stainless steel plate or a coated product thereof, a ceramic coating plate, and a sheet or a molded body mainly composed of polyethylene terephthalate resin, polycarbonate resin, or vinyl chloride resin. Item 12. The coating composition according to any one of Items 1 to 11.   The method for applying the coating composition according to any one of claims 1 to 12, wherein the coating composition is pressurized by electric drive so that the droplets are ejected in a non-contact manner so that the volume of the droplets is 2 nl or less. A method for applying a coating composition, comprising applying a substrate.   The coating method of the coating composition according to claim 13, wherein the substrate is heated to 35 ° C. or higher.   The coating composition application method according to claim 13 or 14, wherein the coating composition is dried by applying air at a wind speed of 1 m / second or more to a substrate within 1 second after application.