JP2011231201A - White ink composition and recorded matter using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a white ink composition having significantly improved rubbing resistance and water-rubbing resistance more than ever before while maintaining shielding properties of an image without causing stickiness of an image surface recorded.SOLUTION: The white ink composition contains a white pigment and fixing resins. The fixing resins include a vinyl chloride resin, a fluorene resin, and polyolefin wax.

Description

  The present invention relates to a white ink composition and a recorded matter using the same.

  Conventionally, white ink compositions containing a metal oxide such as titanium dioxide, zinc oxide, silica, alumina, magnesium oxide, and a white pigment such as barium sulfate or calcium carbonate have been used in various printing methods. The white ink composition is used to erase the background color in order to improve the color development of the color image when recording a color image on a recording medium such as a plastic product or a metal product where the background color is not necessarily white. May be used for When a color image is recorded on a transparent sheet, it may be used for forming a white shielding layer that lowers the transparency of the color image.

The white ink composition may contain a fixing resin for fixing the white pigment to the recording medium. Patent Document 1 discloses a white pigment, a polyurethane resin having a glass transition temperature of −35 to 10 ° C. as a fixing resin, and an SP value of 10 to 15.5 (cal / cm ³ ) ^1/2 as a water-soluble organic solvent. A white ink composition for textile printing containing a polyol is disclosed. According to this configuration, the fastness to washing and the fastness to friction are good, and when used in a dark-colored fabric, good shielding properties can be realized, and an image with excellent on-machine stability can be recorded. .

JP 2009-96914 A

  However, when a urethane-based resin is used as the fixing resin, an image having excellent shielding properties and adhesion to the recording medium can be recorded, while the surface of the image is sticky and a plurality of recording media are stacked. May cause the images to adhere to each other. Further, when a urethane resin is used as the fixing resin, it is possible to improve the shielding performance of the recorded image, but the image has insufficient scratch resistance and water resistance.

  Some embodiments according to the present invention solve the above-mentioned problems, and are not much sticky on the surface of the recorded image, and have much higher scratch resistance and water rub resistance than the conventional one while maintaining the shielding property of the image. An improved white ink composition is provided.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
One aspect of the white ink composition according to the present invention is:
A white ink composition containing a white pigment and a fixing resin,
The fixing resin includes a vinyl chloride resin, a fluorene resin, and a polyolefin wax.

[Application Example 2]
In application example 1,
The vinyl chloride resin and the fluorene resin can be included in a mass ratio of 5: 1 to 1: 6 on a mass basis.

[Application Example 3]
In application example 1 or application example 2,
The polyolefin wax and the fluorene-based resin may be included in an amount ratio of 3: 2 to 1: 5 on a mass basis.

[Application Example 4]
In any one of Application Examples 1 to 3,
The content of the vinyl chloride resin may be 0.5% by mass or more and 10% by mass or less.

[Application Example 5]
In any one of Application Examples 1 to 4,
The white pigment may be titanium dioxide.

[Application Example 6]
In any one of Application Examples 1 to 5,
The vinyl chloride resin may have a minimum film-forming temperature (MFT) of 0 ° C. or higher.

[Application Example 7]
In any one of Application Examples 1 to 6,
The polyolefin wax may have an average particle size of 30 nm to 700 nm.

[Application Example 8]
In any one of Application Examples 1 to 7,
It can further contain at least one selected from alkanediols and glycol ethers.

[Application Example 9]
In any one of Application Examples 1 to 8,
An acetylene glycol surfactant or a polysiloxane surfactant can be further contained.

[Application Example 10]
The white ink composition described in any one of Application Examples 1 to 9 can be applied to an inkjet recording method.

[Application Example 11]
In one aspect of the recorded matter according to the present invention, an image is recorded by the white ink composition described in any one of Application Examples 1 to 10.

  Hereinafter, preferred embodiments of the present invention will be described. The embodiment described below describes an example of the present invention. In addition, the present invention is not limited to the following embodiments, and includes various modifications that are implemented within a range that does not change the gist of the present invention.

1. White ink composition The white ink composition which concerns on one Embodiment of this invention contains a white pigment and fixing resin for fixing the said white pigment. Hereinafter, each component contained in the white ink composition according to the present embodiment will be described in detail.

1.1. White pigment The white ink composition according to the present embodiment contains a white pigment. Examples of white pigments include metal oxides, barium sulfate, and calcium carbonate. Examples of the metal oxide include titanium dioxide, zinc oxide, silica, alumina, and magnesium oxide. Among these, titanium dioxide is preferable from the viewpoint of whiteness and abrasion resistance.

  The content (solid content) of the white pigment is preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less with respect to the total mass of the white ink composition. When the content of the white pigment exceeds the above range, reliability such as clogging of the ink jet recording head may be impaired. On the other hand, if it is less than the above range, the color density such as whiteness tends to be insufficient.

  The average particle size of the white pigment is preferably 30 nm or more and 600 nm or less, more preferably 200 nm or more and 400 nm or less. If the average particle diameter exceeds the above range, the particles may settle and the dispersion stability may be impaired, and the reliability such as clogging of the ink jet recording head may be impaired. On the other hand, when the average particle size is less than the above range, the whiteness tends to be insufficient.

Incidentally, the average particle diameter in the present specification means a d ₅₀ in the particle size accumulation curve. The particle size accumulation curve is obtained by statistically processing the results of measurements that can determine the diameter of particles and the number of particles present in particles dispersed in a liquid such as an ink composition. A kind of curve. The particle size accumulation curve takes the diameter of the particle on the horizontal axis, and the particle mass (the product of volume, particle density, and number of particles when the particle is regarded as a sphere), the particle from the small diameter to the large particle The value (integrated value) integrated toward the vertical axis is taken on the vertical axis. The particle size d ₅₀ is a value obtained by standardizing the vertical axis in the particle size accumulation curve (the total mass of the measured particles is 1) and the vertical axis value is 50% (0.50). This is the value on the horizontal axis, that is, the diameter of the particle.

  The average particle diameter of the white pigment can be measured by a particle size distribution measuring apparatus using a laser diffraction scattering method as a measurement principle. As the particle size distribution measuring device, for example, a particle size distribution meter (for example, “Microtrack UPA” manufactured by Nikkiso Co., Ltd.) having a dynamic light scattering method as a measurement principle can be used.

1.2. Fixing Resin The white ink composition according to this embodiment contains a fixing resin for fixing the white pigment to a recording medium. The white ink composition according to the present embodiment contains at least a vinyl chloride resin, a fluorene resin, and a polyolefin wax as the fixing resin.

1.2.1. Vinyl chloride-based resin The white ink composition according to the present embodiment contains a vinyl chloride-based resin as a fixing resin, so that the adhesion to the recording medium and the water resistance of the image are maintained while maintaining the shielding property of the recorded image. Rubability can be improved.

  The vinyl chloride resin includes not only a homopolymer of vinyl chloride but also a copolymer of vinyl chloride and other monomers. The vinyl chloride resin is preferably a vinyl chloride / acrylic copolymer.

  As the vinyl chloride resin, either an emulsion type dispersed in a solvent in a solvent form or a solution type existing in a dissolved state in a solvent may be used. However, the vinyl chloride resin is dispersed in a particulate form in a solvent. The emulsion type is preferred. The emulsion type can be classified into a forced emulsification type and a self-emulsification type depending on the emulsification method, but any type can be used in the present invention.

  Examples of the emulsion type vinyl chloride resin include “ViniBran 278” and “ViniBran 271” (manufactured by Nissin Chemical Industry Co., Ltd.).

  As a method for producing such a vinyl chloride resin, known methods can be applied. For example, vinyl chloride and an acrylic monomer are dispersed and emulsified in water to obtain an emulsion, and then a persulfate or the like. Generally, an emulsion polymerization method in which a water-soluble polymerization initiator is added and polymerized is used. You may add surfactant, a stabilizer, a pH adjuster, etc. to a reaction system as needed.

  In the present invention, a vinyl chloride resin having a minimum film-forming temperature (hereinafter also referred to as “MFT”) is preferably 0 ° C. or higher, more preferably 30 ° C. or higher. MFT refers to the temperature at which white powdery precipitates are produced and transparent when applied to a film with an aqueous dispersion of 25% solids and then dried with heating to create a temperature gradient. This is the boundary temperature with the temperature at which a thick film is formed. Specifically, MFT can be determined by measuring the film surface temperature during drying after applying a liquid composition of 30 ° C. or higher.

  The content (solid content) of the vinyl chloride resin is preferably 0.5% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 5% by mass with respect to the total mass of the white ink composition. % Or less. If the content of the vinyl chloride resin exceeds the above range, ink reliability (clogging, ejection stability, etc.) may be impaired, and appropriate physical properties (viscosity, etc.) may not be obtained. . In addition, the abrasion resistance of the recorded image may be reduced. On the other hand, if it is less than the above range, the ink fixing property (adhesion between the recording medium and the image) on the recording medium is not excellent, and it is not desirable from the viewpoint of whiteness.

1.2.2. Fluorene Resin The white ink composition according to this embodiment can improve the scratch resistance and water rub resistance of a recorded image by containing a fluorene resin as a fixing resin.

The fluorene resin is not particularly limited as long as it has a fluorene skeleton, and can be obtained, for example, by copolymerizing the following monomer units (a) to (d).
(A) Isophorone diisocyanate (CAS No. 4098-71-9)
(B) 4,4 ′-(9-fluorenylidene) bis [2- (phenoxy) ethanol] (CAS No. 117344-32-8)
(C) 3-hydroxy-2- (hydroxymethyl) -2-methylpropionic acid (CAS No. 4767-03-7)
(D) Triethylamine (CAS No. 121-44-8)

  The fluorene-based resin used in the present invention is a monomer having a fluorene skeleton as shown by 4,4 ′-(9-fluorenylidene) bis [2- (phenoxy) ethanol] (CAS No. 117344-32-8). If it is resin to contain, it will not restrict | limit in particular.

  The content (solid content) of the fluorene-based resin is preferably 0.2% by mass or more and 30% by mass or less, and more preferably 0.5% by mass or more and 10% by mass with respect to the total mass of the white ink composition. Hereinafter, it is particularly preferably 2% by mass or more and 6% by mass or less. If the content of the fluorene-based resin exceeds the above range, the shielding property may be lowered in the recorded image, and cracks may occur. On the other hand, if the amount is less than the above range, an image having excellent scratch resistance and / or water scratch resistance may not be formed.

  In the white ink composition according to the present embodiment, the vinyl chloride resin and the fluorene resin are preferably contained in a mass ratio of 5: 1 to 1: 6 on a mass basis. 1 is particularly preferred. The white ink composition according to the present embodiment is blended with a vinyl chloride resin and a fluorene resin in the above-mentioned quantitative ratio, thereby reducing whiteness, abrasion resistance and water abrasion resistance without deteriorating image shielding. High quality images with excellent recording properties and excellent adhesion to recording media can be recorded. If the amount of vinyl chloride resin exceeds the amount ratio, ink reliability (clogging, ejection stability, etc.) may be impaired, and appropriate physical properties (viscosity, etc.) may not be obtained. is there. In addition, the abrasion resistance of the recorded image may be reduced. On the other hand, when the amount of the fluorene-based resin exceeds the amount ratio, the shielding property of the recorded image is lowered and cracking tends to occur.

1.2.3. Polyolefin Wax The white ink composition according to the present embodiment contains a polyolefin wax as a fixing resin, thereby improving image shielding and preventing image cracking. That is, since the white ink composition according to the present embodiment contains a fluorene-based resin as described above, the image may be cracked. Therefore, it is possible to effectively prevent cracking of the image by further adding polyolefin wax.

  The polyolefin wax is not particularly limited. For example, a wax produced from an olefin such as ethylene, propylene, butylene or a derivative thereof and a copolymer thereof, specifically, a polyethylene wax, a polypropylene wax, a polybutylene wax, and the like. Is mentioned. Among these, polyethylene wax is preferable from the viewpoint of having an excellent effect in preventing cracking of an image. These polyethylene waxes can be used alone or in combination of two or more.

  A commercially available product can be used as the polyolefin wax. As a specific example, Chemipearl series such as “Chemipearl W4005” (manufactured by Mitsui Chemicals, Inc., polyethylene wax, particle size 200 to 800 nm, ring and ball method softening point 110 ° C., penetration method hardness 3, solid content 40%) Can be mentioned. In addition, AQUACER 513 (polyethylene wax, particle size 100 to 200 nm, melting point 130 ° C., solid content 30%), AQUACER 507, AQUACER 515, AQUACER 840 (above, manufactured by Big Chemie Japan Co., Ltd.), Hitech E-7025P, Hitech series such as Hitech E-2213, Hitech E-9460, Hitech E-9015, Hitech E-4A, Hitech E-5403P, Hitech E-8237 (manufactured by Toho Chemical Co., Ltd.), Nopcoat PEM-17 (San Nopco) Manufactured, polyethylene emulsion, particle size 30 nm) and the like. These are commercially available in the form of an aqueous emulsion in which polyolefin wax is dispersed in water by a conventional method. In the white ink composition according to the present embodiment, it can be added directly in the form of an aqueous emulsion.

  The average particle size of the polyolefin wax is preferably 30 nm to 700 nm, more preferably 200 nm to 700 nm. When the average particle diameter of the polyolefin wax is within the above range, cracks in the image can be reduced, but the effect of preventing cracks is further enhanced by using a polyolefin wax having an average particle diameter of 200 nm to 700 nm. .

  The average particle diameter of the polyolefin wax can be measured by a particle size distribution measuring apparatus using a laser diffraction scattering method as a measurement principle. As the particle size distribution measuring device, for example, a particle size distribution meter (for example, “Microtrack UPA” manufactured by Nikkiso Co., Ltd.) having a dynamic light scattering method as a measurement principle can be used.

  The content (solid content) of the polyolefin wax is preferably 0.2% by mass to 30% by mass, and more preferably 0.5% by mass to 10% by mass with respect to the total mass of the white ink composition. Particularly preferably, it is 1% by mass or more and 3% by mass or less. When the content of the polyolefin wax exceeds the above range, the whiteness in the recorded image may be lowered. On the other hand, if it is less than the above range, the effect of preventing cracking of the image cannot be expected.

  In the white ink composition according to the present embodiment, it is preferable that the polyolefin wax and the fluorene-based resin are included in an amount ratio of 3: 2 to 1: 5 on a mass basis. It is particularly preferable that it is contained in a quantitative ratio. The white ink composition according to the present embodiment is excellent in whiteness, shielding properties, rub resistance and water rub resistance by blending the polyolefin wax and the fluorene resin in the above-mentioned quantitative ratio, and the image is not cracked. It is possible to record high-quality images that are prevented. If the polyolefin wax is too much in excess of the amount ratio, the whiteness of the image may be lowered. On the other hand, when the amount of the fluorene-based resin exceeds the amount ratio, the shielding property of the recorded image is lowered and cracking tends to occur.

1.3. Other Components In addition to the above components, the white ink composition according to the present embodiment may contain at least one selected from alkanediols and glycol ethers. Alkanediol and glycol ether can improve the wettability of the recording surface such as a recording medium to increase the ink permeability.

  Examples of the alkanediol include 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1,2-octanediol, 2-Alkanediol is preferred. Of these, 1,2-hexanediol, 1,2-heptanediol, and 1,2-octanediol having 6 to 8 carbon atoms are more preferred because of their particularly high permeability to recording media.

  Examples of the glycol ether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and triethylene. And lower alkyl ethers of polyhydric alcohols such as glycol monomethyl ether, triethylene glycol monobutyl ether, and tripropylene glycol monomethyl ether. Among these, good recording quality can be obtained by using triethylene glycol monobutyl ether.

  The content of at least one selected from these alkanediols and glycol ethers is preferably 1 to 20% by mass, more preferably 1 to 10% by mass, based on the total mass of the white ink composition. .

  The white ink composition according to this embodiment may contain an acetylene glycol surfactant or a polysiloxane surfactant in addition to the above components. Acetylene glycol surfactants or polysiloxane surfactants can increase the wettability of a recording surface such as a recording medium to increase the ink permeability.

  Examples of acetylene glycol surfactants include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, and 3,5. -Dimethyl-1-hexyne-3ol, 2,4-dimethyl-5-hexyn-3-ol and the like. Moreover, a commercial item can also be utilized for acetylene glycol-type surfactant, for example, Olphine E1010, STG, Y (above, Nissin Chemical Co., Ltd. product), Surfynol 104, 82, 465, 485, TG ( As mentioned above, Air Products and Chemicals Inc.) is mentioned.

  Commercially available products can be used as the polysiloxane surfactant, and examples thereof include BYK-347, BYK-348 (above, manufactured by Big Chemie Japan Co., Ltd.) and the like.

  Furthermore, the white ink composition according to this embodiment may contain other surfactants such as an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant.

  The content of the surfactant is preferably 0.01 to 5% by mass and more preferably 0.1 to 0.5% by mass with respect to the total mass of the white ink composition.

  In the white ink composition according to the present embodiment, a polyhydric alcohol may be added in addition to the above components. The polyhydric alcohol can prevent the ink from drying and can prevent clogging of the ink in the ink jet recording head portion.

  Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, glycerin, trimethylolethane, A trimethylol propane etc. are mentioned.

  The content of the polyhydric alcohol is preferably 0.1 to 30% by mass and more preferably 0.5 to 20% by mass with respect to the total mass of the white ink composition.

  The white ink composition according to the present embodiment usually contains water as a solvent. It is preferable to use pure water or ultrapure water such as ion exchange water, ultrafiltration water, reverse osmosis water, or distilled water. In particular, water obtained by sterilizing these waters by ultraviolet irradiation or addition of hydrogen peroxide is preferable because generation of mold and bacteria can be suppressed over a long period of time.

  The white ink composition according to the present embodiment may use an organic solvent in addition to water as a solvent. Examples of such organic solvents include C1-C4 alkyl alcohols such as ethanol, methanol, butanol, propanol, and isopropanol, 2-pyrrolidone, formamide, acetamide, dimethyl sulfoxide, sorbit, sorbitan, acetin, diacetin, and triacetin. And sulfolane. By using such an organic solvent, the permeability to the recording medium can be improved and nozzle clogging can be prevented. These may be used alone or in combination of two or more, and are preferably contained in an amount of about 0.1 to 10% by mass relative to the total mass of the white ink composition.

  The white ink composition according to the present embodiment can be prepared in the same manner as a conventional pigment ink using a conventionally known apparatus such as a ball mill, a sand mill, an attritor, a basket mill, or a roll mill. In the preparation, it is preferable to remove coarse particles using a membrane filter or a mesh filter.

  The white ink composition according to the present embodiment can form a white image by applying it to various recording media. Examples of the recording medium include paper, cardboard, fiber products, sheets or films, plastic, glass, ceramics, and the like.

  The use of the white ink composition according to the present embodiment is not particularly limited, but can be applied to various ink jet recording systems. Examples of the ink jet recording method include thermal jet ink jet, piezo ink jet, continuous ink jet, roller application, spray application, and the like.

2. Recorded matter The present invention can also provide a recorded matter in which an image is formed by the above-described white ink composition. According to the recorded matter according to the present invention, high-quality white recording in which rub resistance and water rub resistance are significantly improved as compared with the prior art while maintaining image shielding without causing stickiness of the recorded image surface. You can get things. The recorded matter according to the present invention is excellent in whiteness and adhesion, and is excellent in quality balance in which bleeding and cracking with the color ink are prevented.

3. EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

3.1. Preparation of white ink composition Titanium dioxide particles, fixing resin, organic solvent, polyhydric alcohol, surfactant and ion-exchanged water were mixed and stirred at the blending amounts shown in Tables 1 and 2, and filtered through a metal filter having a pore size of 5 μm. The white ink compositions of Examples 1 to 19 were obtained by deaeration using a vacuum pump. In addition, the unit of the density | concentration described in Examples 1-19 of Tables 1-2 is a mass%, and solid content conversion density | concentration is all about titanium dioxide particle, a vinyl chloride type resin, a fluorene type resin, and polyethylene wax. It is.

  As the titanium dioxide particles, a commercially available product “NanoTek® Slurry” (manufactured by CI Kasei Co., Ltd.) was used. NanoTek (R) Slurry is a slurry containing titanium dioxide particles having an average particle diameter of 300 nm at a solid content concentration of 15%.

  As the surfactant, “BYK-348” (manufactured by BYK Japan) was used as a polysiloxane surfactant.

The fixing resins described in Tables 1 and 2 are as follows.
・ Vinyl chloride resin A (manufactured by Nissin Chemical Industry Co., Ltd., trade name “Viniblanc 278”, solid content concentration: 45%, MFT: 50 ° C.)
・ Vinyl chloride resin B (manufactured by Nissin Chemical Industry Co., Ltd., trade name “Viniblanc 271”, solid content concentration: 45%, MFT: 0 ° C.)
・ Polyethylene wax A (Bic Chemie Japan, trade name “AQ513”, average particle size 100 to 200 nm)
Polyethylene wax B (Mitsui Chemicals, trade name “W4005”, average particle size 200-700 nm)
Polyethylene wax C (Mitsui Chemicals, trade name “W4005”, average particle size 200-700 nm)
Polyethylene wax C (manufactured by San Nopco, trade name “Nopcoat PEM-17”, average particle size 30 nm)

  The fluorene resins described in Tables 1 and 2 were synthesized as follows. The fluorene resin is composed of 30 parts by mass of isophorone diisocyanate, 50 parts by mass of 4,4 ′-(9-fluorenylidene) bis [2- (phenoxy) ethanol], 3-hydroxy-2- (hydroxymethyl) -2-methylpropionic acid. 100 parts by weight and 30 parts by weight of triethylamine were weighed and mixed well, and then synthesized by stirring at 120 ° C. for 5 hours in the presence of a catalyst. The obtained fluorene-based resin was a resin having a molecular weight of 3300, containing 4,4 '-(9-fluorenylidene) bis [2- (phenoxy) ethanol] having a monomer composition ratio of about 50% by mass.

3.2. Evaluation of Printed Materials The white ink compositions shown in Tables 1 and 2 were filled in the black ink chambers of dedicated cartridges for inkjet printers (product name “PX-G930” manufactured by Seiko Epson Corporation), respectively. The ink cartridge thus produced was installed in a printer and a printing test was performed. Commercially available ink cartridges other than black were installed. This is used as a dummy and is not used in the evaluation of the present embodiment, so it is not involved in the effect.

Next, printing was performed at a resolution of 1440 × 720 dpi on “Lumirror (R) S10-100 μm” (manufactured by Toray Industries, Inc., a commercially available PET sheet without an ink receiving layer). The printing pattern was a 100% duty solid pattern. “Duty” is a value calculated by the following equation.
duty (%) = number of actual printing dots / (vertical resolution × horizontal resolution) × 100
(Where “number of actual print dots” is the number of actual print dots per unit area, and “vertical resolution” and “horizontal resolution” are resolutions per unit area. 100% duty is a single color for a pixel. Means the maximum ink mass.)
The following evaluation tests were performed on the recorded matter obtained by the above steps.

3.2.1. Evaluation of whiteness CIE / L ^* a ^* b ^* L ^* value in the color system is measured using a commercially available colorimeter based on black, for example, Gretag Macbeth Spectroscan and Spectrolino (manufactured by X-Rite). Thus, the whiteness of the recorded matter was determined. The evaluation criteria are as follows.
20 points: L value is 75 or more 15 points: L value is 73 or more and less than 75 10 points: L value is 70 or more and less than 73 5 points: L value is less than 70

3.2.2. Evaluation of shielding property The obtained recorded matter was set in a declination calorimeter (manufactured by JASCO Corporation, model “ARM-500V”), and transmitted at each wavelength in the visible light region (380 nm to 700 nm). The rate Tn (%) was measured. From the measurement results, the shielding property was evaluated by calculating the integral value of the transmittance Tn for each wavelength in the visible light region (380 nm to 700 nm). According to this evaluation method, the integral value obtained is a value between 0 and 32000, 0 if completely shielded, and 32000 if completely transmitted. The evaluation criteria are as follows.
20 points: integral value of transmittance Tn is 120 or less 15 points: integral value of transmittance Tn is 120 or more and less than 150 10 points: integral value of transmittance Tn is 150 or more and less than 200 5 points: integration of transmittance Tn Value is 200 or more

3.2.3. Evaluation of surface condition Next, the surface condition of the recorded material was examined. The evaluation of the surface condition was performed by the person in charge of the test touching the surface of the recorded material with a finger, and was judged according to the following evaluation criteria.
10 points: The printed surface is not sticky.
5 points: The printed surface is slightly sticky.
-20 points: The printed surface is sticky.

3.2.4. Evaluation of rubbing resistance The rubbing resistance was determined by drying a PET sheet on which a white ink composition was recorded for 10 minutes in a thermostatic bath at 50 ° C., and then performing a “rubbing test with cloth” by a tester. This rubbing test with a cloth is a test method in which the printed surface is rubbed two to three times with a cloth. The evaluation criteria are as follows.
10 points: The printed surface is not damaged even when rubbed with a cloth.
5 points: The printed surface is slightly scratched when rubbed with a cloth.
−20 points: The printed surface is clearly scratched when rubbed with a cloth.

3.2.5. Evaluation of water rub resistance Water rub resistance was determined by drying a PET sheet on which a white ink composition was recorded in a thermostatic bath at 50 ° C. for 10 minutes, and then performing a “rub test with cloth” by a tester. In addition, water is fully infiltrated into this cloth. This rubbing test with a cloth is a test method in which the printed surface is rubbed two to three times with a cloth. The evaluation criteria are as follows.
10 points: The printed surface does not peel off even when rubbed with a cloth.
5 points: The print surface peels slightly when rubbed with a cloth.
-20 points: The print surface is completely peeled off when rubbed with a cloth.

3.2.6. Evaluation of Adhesiveness Adhesiveness was determined by drying a PET sheet on which a white ink composition was recorded in a thermostatic bath at 50 ° C. for 10 minutes, and then performing a “rubbing test with a nail” by a tester. This rubbing test with a nail is a test method in which the printed surface is rubbed 2-3 times with a nail. The evaluation criteria are as follows.
10 points: Does not peel off even when rubbed with nails.
5 points: Slightly peeled off when rubbed with nails.
-20 points: Completely peeled off with a nail.

3.2.7. Evaluation of Smear (1) Recording Method A recording medium whose recording surface is a plastic film (Lumirror (R) S10-100 μm (manufactured by Toray Industries, Inc.)) was filled with five colors of C, M, Y, K, and white. Using an ink jet printer (product name “PX-G930”, manufactured by Seiko Epson Corporation), the sheet feeder is heated to 70 ° C. with a dryer so that the recording medium is 45 ° C. at the time of printing. A 100% duty white solid pattern was printed at a resolution of 1440 × 720 dpi. Immediately after that, a pattern in which two colors were in contact with each other at a duty of 10% to 100% from the top of the white solid was printed at a resolution of 1440 × 720 dpi.

(2) Evaluation method The presence or absence of bleeding at the portion where the two colors of the printed pattern touch each other was examined with each duty and evaluated according to the following criteria.
10 points: No bleeding even at 100% duty.
5 points: No bleeding when the duty is up to 70%.
0 point: No bleeding up to 40% duty.
-20 points: bleeding at a duty of less than 40%.

3.2.8. Evaluation of reliability Reliability is determined by the person in charge of the test whether the clogging of the head part of the ink jet printer is likely to occur after the white recorded matter is produced by the above-described process, and whether the clogging is recovered by cleaning. Judged. The evaluation criteria are as follows.
10 points: Head clogging hardly occurs and easily recovered by cleaning.
0 point: Although clogging of the head hardly occurs, it is difficult to recover by cleaning.
0 point: Although clogging of the head is likely to occur, it is easily recovered by cleaning.
-20 points: Head clogging easily occurs, and is difficult to recover by cleaning.

3.2.9. Evaluation of cracks Cracks were determined by visually examining the image surface after the PET sheet on which the white ink composition was recorded was dried in a thermostatic bath at 50 ° C. for 10 minutes. The evaluation criteria are as follows.
0 point: No cracking occurs after drying.
−20 points: Cracking occurs after drying.

3.2.10. Overall quality Quality was comprehensively determined from the total score of the above evaluation results. If the total score is 60 points or more, it can be used without any problem in quality, and if it is 70 points or more, it can be evaluated that the white ink composition is particularly excellent in quality. If the total score is less than 60, good results are not obtained for any of the evaluation items, and therefore it can be evaluated that the product is ineligible.

3.3. Evaluation result The above evaluation result is combined with Tables 1-2, and is shown.

  According to the white ink compositions of Examples 1 to 13 described in Tables 1 and 2, all of them are excellent in whiteness, scratch resistance, adhesion and water rub resistance without impairing the shielding properties of the recorded images. It was found that cracking can be prevented.

  According to the white ink composition of Example 14 (vinyl chloride resin: fluorene resin = 6: 1), it was found that unevenness caused the whiteness to decrease and the reliability to be remarkably insufficient.

  According to the white ink composition of Example 15 (with no vinyl chloride resin added), it was found that the shielding properties of the recorded image and the adhesion to the recording medium were significantly reduced.

  According to the white ink composition of Example 16 (no addition of fluorene resin), it was found that the rub resistance of the recorded image was remarkably lowered.

  According to the white ink composition of Example 17 (no addition of polyolefin wax), it was found that the recorded image was deteriorated in abrasion resistance and cracked in the image.

  According to the white ink composition of Example 18 (vinyl chloride-based resin: fluorene-based resin = 1: 7), it was found that whiteness was lowered due to unevenness and the reliability was extremely insufficient.

  According to the white ink composition of Example 19 (vinyl chloride resin: fluorene resin = 1: 7), it was found that image cracking occurred.

  The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

Claims (11)

A white ink composition containing a white pigment and a fixing resin,
The fixing resin is a white ink composition containing a vinyl chloride resin, a fluorene resin, and a polyolefin wax. In claim 1,
A white ink composition comprising the vinyl chloride resin and the fluorene resin in a mass ratio of 5: 1 to 1: 6 on a mass basis. In claim 1 or claim 2,
A white ink composition comprising the polyolefin wax and the fluorene resin in an amount ratio of 3: 2 to 1: 5 on a mass basis. In any one of Claims 1 to 3,
A white ink composition, wherein the content of the vinyl chloride resin is 0.5% by mass or more and 10% by mass or less. In any one of Claims 1 thru | or 4,
A white ink composition, wherein the white pigment is titanium dioxide. In any one of Claims 1 thru | or 5,
A white ink composition, wherein the vinyl chloride resin has a minimum film-forming temperature (MFT) of 0 ° C or higher. In any one of Claims 1 thru | or 6,
A white ink composition, wherein the polyolefin wax has an average particle size of 30 nm to 700 nm. In any one of Claims 1 thru | or 7,
A white ink composition further comprising at least one selected from alkanediols and glycol ethers. In any one of Claims 1 thru | or 8,
A white ink composition further comprising an acetylene glycol surfactant or a polysiloxane surfactant.   The white ink composition according to any one of claims 1 to 9, which is applied to an ink jet recording system.   A recorded matter in which an image is recorded with the white ink composition according to any one of claims 1 to 10.