JP2005194500A - Ink composition imparting glossy feeling and method for evaluating glossy feeling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition capable of forming a recorded image excellent in glossy feeling and to provide a method for evaluating the glossy feeling of the recorded image that is approximately coincident with the judgement of gloss properties by the visual observation of a person and has superiority as an indicia. <P>SOLUTION: The ink composition comprises at least a nonaqueous solvent wherein the surface tension becomes 30 mN/m or less when dissolved in water to form a 10 wt% aqueous solution and 0.1 wt% or more of an organic amine. The method for evaluating the glossy feeling of the recorded image uses a calculated value obtained from the formula:(glossy feeling)=(glossiness)/(image clarity)<SP>2</SP>as an indicia of the glossy feeling. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink composition capable of forming a recorded image having excellent glossiness, and a method for evaluating the glossiness of a recorded image, which is substantially coincident with human visual judgment of glossiness and has an advantage as an index. .

  Conventionally, various techniques for improving the image clarity and gloss of a recorded image formed by an ink composition or the like and a recorded matter have been proposed and disclosed.

  For example, in Japanese Patent Application Laid-Open No. 2003-103898, inkjet recording including a step of forming a pigment image by ejecting pigment ink onto a recording medium and an adjustment step of adjusting the C value of the pigment image to 60 or more. An inkjet pigment image having a C value of 60 or more in an inkjet pigment image obtained by jetting a pigment ink to a method and a recording medium is disclosed (Patent Document 1). The C value referred to in this document is a value measured by a reflection method using an optical comb of 2 mm among the image sharpness defined in JIS-K-7105.

  The invention described in this document has gloss equivalent to that of a silver salt photograph, has no bronzing, is excellent in water resistance and oxidation gas resistance, and can be used for commercial applications such as high-speed and continuous output for print output services. It has been proposed for the purpose of providing an inkjet pigment image and an inkjet recording method. Such a recording method is specifically shown as an embodiment in which the adjustment step includes a heat fixing step and a pressurizing step. Further, the embodiment of the pigment image is specifically shown by the definition of the center line average roughness Ra, the 60-degree gloss, the average particle diameter of the pigment particles, and the like.

  However, with this technique, the solid content of the pigment is relatively small, and actually pressure and heat treatment are required, and sufficient glossiness of the recorded image is not yet obtained.

Furthermore, with regard to the glossiness of the recorded image, the evaluation method has not been uniform in the past, and there has actually been a shift between the evaluation of the glossiness by human eyes and the evaluation as objective numerical data.
JP 2003-103898 A

  The problem to be solved by the present invention is a problem in the above-described prior art.

  Accordingly, an object of the present invention is to provide an ink composition capable of forming a recorded image having excellent gloss.

  Another object of the present invention is to provide a method for evaluating the glossiness of a recorded image, which is substantially coincident with the judgment of glossiness by human eyes and has an advantage as an index.

  As a result of diligent research, the present inventor has found that an ink composition using an alkanediol in a certain amount or more together with an organic amine can achieve the object. Furthermore, the knowledge that the ink composition using the specific nonaqueous solvent containing alkanediols etc. and organic amine can achieve the said objective was also acquired after that.

  In addition, the inventor has also found that the evaluation method of glossiness of a recorded image using at least a glossiness specified from a predetermined glossiness and a predetermined sharpness as an index can achieve the other object. Obtained.

  The present invention has been made on the basis of the above-mentioned findings. “1” a non-aqueous solvent having a surface tension of 30 mN / m or less when dissolved in water to form a 10% by weight aqueous solution, and 0.1% by weight or more An ink composition comprising at least the organic amine is provided.

  The present invention also provides the following inventions.

  [2] The ink composition according to 1, wherein the non-aqueous solvent is alkanediol. “3” The ink composition according to 2, wherein the alkanediol is a 1,2-alkanediol which may have a substituent. “4” The ink composition according to any one of 1 to 3, wherein the organic amine is a tertiary amine. “5” The ink composition according to any one of 1 to 4, further comprising a polysiloxane surfactant. "6" The ink composition according to any one of 1 to 5, wherein the color material of the ink is a pigment, and the solid content of the pigment is 3.0% by weight or more. “7” The ink composition according to any one of 1 to 6, which forms a recorded image having a glossiness of 2.5 or more at a duty of 80%. [8] The ink composition according to any one of 1 to 6, which forms a recorded image having a glossiness of 2.5 or more at a duty of 80% of the secondary color. “9” The ink composition according to any one of 1 to 8, which forms a recorded image having a glossiness of 40 or more and a sharpness of less than 4.0 at a duty of 80%.

  [10] A method for evaluating the glossiness of a recorded image, wherein the calculated value obtained by the following equation is used as a glossiness.

(Glossy) = (Glossiness) / (Vividness) ²
(In the formula, the glossiness is 12V50W halogen lamp as the light source, ND-10 is used as the filter, and the incident light is applied to the recorded image from the slit having the incident angle of 45 degrees and the width of 1 mm at the sensitivity of 500 and the turning angle of 0 degree. When the reflected light is reflected by the image and emitted from the slit having a width of 1.5 mm when irradiated, the light source is set so that the glossiness of the standard plate is 42.5 within a reflection angle range of 42 to 48 degrees. This is the highest value of the reflected light intensity values measured as relative values when the voltage applied to the image is adjusted.The sharpness is measured when obtaining the glossiness (maximum value of reflected light intensity). The reflected light intensity is the width of the reflection angle at which the value of the reflected light intensity is 0.6 or more under this condition.
[11] An apparatus for measuring glossiness of a recorded image, wherein a calculated value obtained by the following formula is automatically calculated and output as glossiness.

(Glossy) = (Glossiness) / (Vividness) ²
(In the formula, the glossiness is 12V50W halogen lamp as the light source, ND-10 is used as the filter, and the incident light is applied to the recorded image from the slit having the incident angle of 45 degrees and the width of 1 mm at the sensitivity of 500 and the turning angle of 0 degree. When the reflected light is reflected by the image and emitted from the slit having a width of 1.5 mm when irradiated, the light source is set so that the glossiness of the standard plate is 42.5 within a reflection angle range of 42 to 48 degrees. This is the highest value of the reflected light intensity values measured as relative values when the voltage applied to the image is adjusted.The sharpness is measured when obtaining the glossiness (maximum value of reflected light intensity). The reflected light intensity is the width of the reflection angle at which the value of the reflected light intensity is 0.6 or more under this condition, and the sharpness of the standard plate is 1.3 or more and 1.5 or less under these conditions.

  According to the ink composition of the present invention, it is possible to form a recorded image having excellent glossiness, and according to the method for evaluating the glossiness of the recorded image according to the present invention, determination of glossiness by human visual observation. It is possible to evaluate with superiority as an index.

Ink Composition Hereinafter, the ink composition of the present invention will be described in detail based on preferred embodiments thereof.

  As described above, the ink composition of the present invention comprises a non-aqueous solvent having a surface tension of 30 mN / m or less when dissolved in water to form a 10 wt% aqueous solution, and an organic amine of 0.1 wt% or more. It contains at least.

  Since the present invention has the above-described configuration, it is possible to form a recorded image (recorded material) with excellent gloss. In the present invention, “glossiness” means glossiness calculated by an evaluation method described later.

The non-aqueous solvent used in the present invention is a solvent other than water that has a surface tension of 30 mN / m or less when dissolved in water to form a 10% by weight aqueous solution.
The non-aqueous solvent is not particularly limited as long as it has the above-mentioned characteristics, but when forming a recorded image, the wettability to a recording surface of a recording medium or the like can be improved and the ink permeability can be increased. In this respect, an organic compound having one or more hydrophilic groups such as alkanediol is preferable. Preferred examples of the alkanediol include 1,2-alkanediol (including those having a substituent). More preferably 1,2-C (carbon number) 4-8 alkanediol, more preferably 1,2-C4-6 alkanediol, most preferably 1,2-hexanediol or 4-methyl-1 , 2-pentanediol.

When 1,2-hexanediol is used, 1,2-hexanediol should be dissolved in water and blended into the ink composition as a 10 wt% solvent aqueous solution (surface tension is 26.6 mN / m). Can do.
When 4-methyl-1,2-pentanediol is used, 4-methyl-1,2-pentanediol is dissolved in water to give a 10% by weight solvent aqueous solution (surface tension is 25.2 mN / m ) As an ink composition.
This surface tension was measured with a platinum plate using an automatic dynamic surface tension meter CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.).

  The content of the non-aqueous solvent relative to the total weight of the ink composition is not particularly limited as long as it is within a range in which the effect of the present invention of forming a recorded image having excellent glossiness can be achieved.

  When the alkanediol is used, the content relative to the total weight of the ink composition can enhance the wettability of the recording medium or the like to the recording surface when forming a recorded image, and increase the ink permeability. From the viewpoint of ink ejection stability and storage stability, it is preferably 7% by weight or more, particularly 7 to 25% by weight, and more preferably 10 to 20% by weight.

  As the organic amine used in the present invention, the wettability of the recording medium or the like to the recording surface can be increased when forming a recorded image, and the ink permeability can be increased, and the pH of the ink composition can be easily set. Tertiary amines and the like are preferable because they can be adjusted within a suitable range. Examples of the tertiary amine include alkanolamines such as triethanolamine. The ink composition of the present invention preferably has a pH of 8 to 12, particularly 8 to 10. When the pH is within such a range, deterioration of the member in contact with the ink can be prevented.

  The content of the organic amine with respect to the total weight of the ink composition is 0.1% by weight or more. From the viewpoint of ink ejection stability and storage stability, it is preferably 0.1 to 2.0% by weight, more preferably 0.3 to 1.0% by weight.

  The ink composition of the present invention contains a polysiloxane-based surfactant in that it can increase the wettability of a recording medium or the like to a recording surface when forming a recorded image to increase the ink permeability. It is preferable.

  Examples of the polysiloxane surfactant include those having a static contact angle change of 8 degrees to 14 degrees and a dynamic surface tension change of 10 or more. Those are preferred.

  Here, the time-dependent change in the static contact angle was determined by dropping 0.1% by weight of the above surfactant aqueous solution at 23 ° C. onto photographic paper <Glossy> (manufactured by Seiko Epson Corporation). The difference between the contact angle after 0.3 seconds and the contact angle after 30 seconds from the contact of the droplet.

  The dynamic surface tension changes with time using a dynamic surface tensiometer (bubble pressure dynamic surface tensiometer BP2 manufactured by KRUSS), and the dynamic surface of the aqueous surfactant solution having a concentration of 0.1% by weight is used. Tension is measured at 23 ° C. and refers to the difference in dynamic surface tension between when measured at 10 Hz (10 bubbles / 1 second) and when measured at 1 Hz (1 bubble / 1 second).

  Whether it is poorly water-soluble or not can be judged by the white turbidity when the surfactant is diluted 1000 times by weight (0.1% weight concentration) at 23 ° C.

  Moreover, as a polysiloxane-type surfactant, what is marketed can also be utilized, for example, BYKUV3510, BYK-347, BYK-348 etc. (made by Big Chemie Japan Co., Ltd.) are mentioned. Among these, BYKUV3510 is preferable because it is hardly water-based, does not have an acrylic group, has a reduced friction coefficient of a recorded image, and can improve glossiness.

  Furthermore, the ink composition of the present invention is selected from the group consisting of other surfactants, specifically, acetylene glycol surfactants, anionic surfactants, nonionic surfactants, and amphoteric surfactants. One or more surfactants can also be used.

  Among these, acetylene glycol surfactants include, for example, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6- Diol, or 3,5-dimethyl-1-hexyn-3ol, 2,4-dimethyl-5-hexyn-3-ol and the like can be mentioned. Commercially available acetylene glycol surfactants can also be used. For example, Olphine E1010, STG, Y (trade name, manufactured by Nissin Chemical Co., Ltd.), Surfynol 61, 104, 82, 465, 485 or TG (Trade name, manufactured by Air Products and Chemicals Inc.).

  The content of the surfactant is preferably 0.01 to 5% by weight, more preferably 0.05 to 0.5% by weight, based on the total weight of the ink composition.

  The color material used in the ink composition of the present invention is not particularly limited, and a pigment or a dye can be used, but it is particularly preferable to use a pigment.

  As the pigment, inorganic pigments and organic pigments can be used, and each can be used alone or in combination. As the inorganic pigment, for example, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can be used in addition to titanium oxide and iron oxide. Examples of the organic pigment include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, Dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (for example, basic dye type chelates, acidic dye type chelates), nitro pigments, nitroso pigments, aniline black, and the like can be used. Specifically, as will be described below, a desired pigment is used according to each color ink. In the following, an example in which the ink composition of the present invention is applied as a black ink, a yellow ink, a magenta ink, a light magenta ink, a cyan ink, or a light cyan ink is described as an example. The pigment is not limited to these examples.

  Examples of the pigment used in the black ink include carbon black, for example, No. manufactured by Mitsubishi Chemical Corporation. 2300, no. 900, HCF88, No. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, No2200B etc. are Raven5750, Raven5250, Raven5000, Raven3500, Raven1255, Raven700, etc. made by Columbia Co. , Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. are available from Degussa Color Black FW1, Color Black FW2, Color Black FW18, Color Black FW18, Color Black FW200, Col. S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 and the like.

  Examples of pigments used in yellow ink include C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14C, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 114, 128, 129, 151, 154 and the like.

  Examples of pigments used in magenta ink and light magenta ink include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 112, 123, 168, 184, 202, C.I. I. Pigment Violet 19 etc. are mentioned.

  Examples of pigments used for cyan ink and light cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15: 3, 15:34, 16, 22, 60, C.I. I. Vat Blue 4, 60 etc. are mentioned.

  The pigment content (pigment solid content) is preferably 3.0% by weight or more based on the total weight of the ink composition in terms of color development on plain paper. The content of the pigment is more preferably 3.0% by weight or more and 10.0% by weight or less, and particularly preferably 3.0% by weight or more and 4.0% by weight or less.

  The ink composition of the present invention preferably uses the above-described pigment and contains a dispersant for dispersing the pigment. As the dispersant, those similar to those in this type of pigment ink can be used without particular limitation, and examples thereof include a cationic dispersant, an anionic dispersant, a nonionic dispersant, and a surfactant. Examples of anionic dispersants include polyacrylic acid, polymethacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid. Copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid-alkyl acrylate copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, styrene-α-methylstyrene-acrylic acid copolymer Styrene-α-methylstyrene-acrylic acid-alkyl acrylate copolymer, styrene-maleic acid copolymer, vinyl naphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene Copolymer, vinyl acetate-maleic ester Examples include copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers, and the like. Examples of anionic surfactants include sodium dodecylbenzenesulfonate, sodium laurate, ammonium salt of polyoxyethylene alkyl ether sulfate, and examples of nonionic surfactants include polyoxyethylene alkyl. Examples include ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, and the like, and one or more of these are used. In particular, it is preferable to use a styrene- (meth) acrylic acid copolymer from the viewpoint of enhancing the dispersion stability of the pigment.

In the present invention, the dispersant may or may not be contained, but a self-dispersing pigment may be used without using a dispersant (0% by weight). Incidentally, the self-dispersing pigment has a functional group (dispersibility imparting) of one or more selected from the group consisting of —COOH, —CHO, —OH, —SO ₃ H and salts thereof on the surface of the pigment. The pigment is treated so as to have a group) and can be uniformly dispersed in the water-based ink without adding a dispersant separately. The term “dispersed” as used herein refers to a state in which a self-dispersing pigment is stably present in water without a dispersant, and not only in a dispersed state but also in a dissolved state. Shall be included.

  The content of the dispersant with respect to the total weight of the ink composition of the present invention is preferably 0.1 to 10% by weight, more preferably 0.3 to 6% by weight in terms of solid content.

  Further, the dispersant is usually contained in an amount of 140% by weight or less, preferably 15 to 60% by weight in terms of solid content, based on the weight of the pigment.

  When used for inkjet, the ink composition of the present invention preferably contains a polyhydric alcohol from the viewpoint of preventing drying of the ink and preventing clogging at the head of the inkjet printer.

  Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, glycerin, and trimethylol. Examples include ethane and trimethylolpropane.

  The content of the polyhydric alcohol is preferably 0.1 to 30% by weight, more preferably 0.5 to 20% by weight, based on the total weight of the ink composition.

  The ink composition of the present invention can also contain glycol ethers from the viewpoint of enhancing the solubility of the poorly water-soluble surfactant.

  As glycol ethers, 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, triethylene Mention may be made of lower alkyl ethers of polyhydric alcohols such as glycol monomethyl ether, triethylene glycol monobutyl ether, tripropylene glycol monomethyl ether and the like. In particular, when triethylene glycol monobutyl ether is used, good recording quality can be obtained.

  The glycol ether content is preferably 0.1 to 25.0% by weight, more preferably 0.1 to 7.0% by weight, based on the total weight of the ink composition.

  Further, the ink composition of the present invention may contain other substances having a penetration promoting action, for example, lower alcohols such as methanol, ethanol and iso-propyl alcohol.

  The ink composition of the present invention is not particularly limited in its application, but is preferably used for ink jet recording such as ink jet recording using an ink jet printer and a discharge system for various functional elements using an ink jet method.

  The ink composition of the present invention contains a specific non-aqueous solvent and an organic amine, and various other additives described above, and 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 is prevented over a long period of time.

  The ink composition of the present invention further includes a fixing agent such as a water-soluble rosin, an antifungal agent / preservative such as sodium benzoate, an antioxidant / ultraviolet absorber such as an allophanate, and a chelating agent as necessary. , Other additives such as oxygen absorbers can be contained, and one or more of these can be used.

  The ink composition of the present invention 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, a mesh filter or the like.

  The ink composition of the present invention can form a recorded image with excellent glossiness by the above-described configuration. According to the ink composition of the present invention, a recorded image having a glossiness of 2.5 or more can be formed at a duty of 80%. In particular, as a suitable ink composition, a recorded image having a glossiness of 3.5 or more at a duty of 80% is formed.

  Further, according to the ink composition of the present invention, it is possible to form a recorded image having a glossiness of 2.5 or more at a duty of 80% of the secondary color.

  Further, according to the ink composition of the present invention, it is possible to form a recorded image having a glossiness of 40 or more and a sharpness of less than 4.0 at a duty of 80%. In the present invention, “glossiness” and “clearness” mean glossiness and sharpness defined in an evaluation method described later, respectively. In particular, as a suitable ink composition, a recorded image having a glossiness of 50 or more and a sharpness of 3.8 or less at a duty of 80% is formed.

  The ink composition of the present invention can also impart glossiness, glossiness, and sharpness of a recorded image at each of the following duties.

Duty 100%; glossiness 2.8 or more, preferably 3.7 or more,
Glossiness of 40.0 or more, preferably 48.0 or more,
Sharpness 3.8 or less, preferably 3.6 or less.

Duty 60%; glossiness 1.7 or more, preferably 2.4 or more,
Glossiness of 35.0 or more, preferably 45.0 or more,
Sharpness 4.5 or less, preferably 4.3 or less.

  The present invention can also provide an ink set comprising at least the above-described ink composition in an ink set comprising a plurality of ink compositions. According to the ink set of the present invention, it is possible to obtain a recorded image composed of a plurality of colors with excellent gloss.

  The present invention can also provide an ink cartridge containing at least the ink composition described above. According to the ink cartridge of the present invention, it is possible to easily transport ink that can obtain a recorded image with excellent gloss.

  The present invention can also provide a recording method for recording with the ink composition described above, a recording apparatus such as an ink jet printer, and other recording systems. According to the recording system of the present invention, a recorded image with excellent gloss can be obtained.

  The present invention can also provide a recorded matter in which an image is formed on a recording surface with the ink composition described above. According to the recorded matter of the present invention, it is possible to obtain a recorded matter having a recorded image with excellent gloss.

Evaluation Method of Glossiness of Recorded Image The evaluation method of the present invention is characterized in that a calculated value obtained by the following formula is indexed as glossiness.

(Glossy) = (Glossiness) / (Vividness) ²

  Here, the glossiness indicates the degree of glossiness of a recorded image formed by the ink composition or the like described above. A 12V50W halogen lamp is used as a light source, ND-10 is used as a filter, and sensitivity is 500. At a 0 degree angle, when incident light is irradiated onto a recorded image from a slit having a width of 1 mm at an incident angle of 45 degrees, the reflection angle of the reflected light reflected by the image and emitted from the slit having a width of 1.5 mm When the voltage applied to the light source is adjusted so that the glossiness of the standard plate is 42.5 in the range of 42 degrees to 48 degrees, it means the highest value among the reflected light intensity values measured as relative values. . The standard plate here means black optical glass having a refractive index of 1.519. Such glossiness is measured by a measuring method as shown in FIG. FIG. 3 is a schematic diagram for explaining a glossiness measurement method. The glossiness can be obtained with the GP-200 model of Murakami Color Research Laboratory under the above measurement conditions.

  The sharpness refers to the degree of sharpness of a recorded image formed by the above-described ink composition or the like (also called image clarity), and the above-mentioned glossiness (maximum reflected light intensity). Is the width of the reflection angle at which the value is 0.6 or more out of all the values of the reflected light intensity measured when obtaining. Specifically, a portion indicated by an arrow in the graph shown in FIG. FIG. 4 is a graph showing the relationship between the reflection angle and the glossiness, and is a schematic diagram for explaining the sharpness. The sharpness can be obtained by analyzing data obtained under the above measurement conditions using GP-200 model of Murakami Color Research Laboratory.

  According to the evaluation method of the present invention, it is substantially coincident with the judgment of glossiness by human eyes, and an advantage can be obtained as an index of glossiness of a recorded image.

Glossiness Measurement Device The measurement device according to the present invention automatically calculates and outputs a calculated value obtained by the following formula as glossiness.

(Glossy) = (Glossiness) / (Vividness) ²
The significance of glossiness, glossiness and sharpness in the formula is the same as the matters detailed in the evaluation method described above.

  According to the measuring apparatus of the present invention, it is substantially coincident with the judgment of glossiness by human eyes, and an advantage can be obtained as an index of glossiness of a recorded image.

Examples Hereinafter, the present invention will be described more specifically with reference to examples and test examples of the present invention. However, the present invention is not limited to the examples. Unless otherwise specified, the blending ratio (%, part) and ratio indicate weight%, weight part and weight ratio, respectively.

(Preparation of ink composition and creation of recorded image)
An ink composition having the composition shown in Table 1 was prepared, and the ink composition was filled in an ink cartridge of an ink jet printer MC2000 (Seiko Epson Corporation). The ink was used for photographic paper <glossy> (Seiko Epson Corporation). ) Were solid-printed at a duty of 100%, 80%, 60% and 40% (colored portion was 7 cm * 19 cm). The resolution was 720 * 720 dpi.

（記録物の評価）
得られた記録物について以下の方法に従い耐擦性、光沢度、鮮映性、光沢感を評価した。

(Evaluation of recorded materials)
The obtained recorded material was evaluated for abrasion resistance, glossiness, sharpness and glossiness according to the following methods.

Abrasion resistance:
Using the Toyo Seiki's Souzaland Love Tester test machine used in JIS standards, the recorded part (image part) of the recorded material is wrapped around the operating part, and double-sided quality paper made by Seiko Epson Corporation is placed on the stage. The attached and recorded part was rubbed 10 times with double-sided fine paper. In the test, a recorded material that had passed 24 hours after recording was used.

Glossiness:
Using an automatic goniophotometer (GP-200 type) from Murakami Color Research Laboratory, with an incident angle of 45 degrees (slit width: incident side φ1 mm, reflection side φ1.5 mm), sensitivity 500, ringing angle 0 degree, and reflection The reflected light intensity at an angle of 42 to 48 degrees was measured. At this time, a halogen lamp of 12V50W was used as the light source, and ND-10 was used as the filter, and the voltage applied to the light source was adjusted so that the glossiness of the standard plate was 42.5. The glossiness of the recorded material is the highest value among the reflected light intensity values measured under the measurement conditions. The reproduction error was ± 2.0 or less. Further, FIG. 1 shows the relationship between the duty and glossiness of a recorded matter obtained from each ink composition.

Sharpness:
From the measurement result of the reflected light intensity under the above conditions (entire values), the width of the reflection angle at which the reflected light intensity value is 0.6 or more was evaluated as sharpness. The reproduction error was ± 0.2 or less.

Glossiness:
Using the above glossiness and sharpness evaluation results, a calculated value obtained by the following formula was obtained.

(Glossy) = (Glossiness) / (Vividness) ²
Further, FIG. 2 shows the relationship between the duty and glossiness of the recorded matter obtained from each ink composition.

  Further, the glossiness of the recorded matter was also visually determined. This judgment tester is 50 people in their 20s to 40s randomly selected. The determination criteria are as follows.

Visual criteria for glossiness:
S: I feel a gloss level that can be recognized as a perfect mirror surface.

  AA: Glossiness is sufficiently felt.

  A: Glossiness is slightly insufficient.

  B: Glossiness feels insufficient.

  C: It can be clearly seen that there is no gloss.

  The above evaluation results are shown in Table 2.

表２と図１及び図２のグラフから明らかなように、Ｄｕｔｙ６０％とＤｕｔｙ８０％による記録画像において、目視では明らかな有意差があるにも拘らず、光沢度を指標とした場合は、数値的有意差は認められない。よって、光沢度は指標として不充分である。

As is clear from Table 2 and the graphs of FIGS. 1 and 2, in the recorded images with a Duty of 60% and a Duty of 80%, there is a numerical value when the glossiness is used as an index even though there is a significant difference visually. There is no significant difference. Therefore, glossiness is insufficient as an index.

  In addition, in the recorded image with a Duty of 60%, the recorded images obtained in Examples 1 to 3 and the recorded images obtained in Comparative Examples 1 to 3 have a clear significant difference although they are clearly visible. When projection is used as an index, the numerical superiority is small in consideration of reproduction errors.

  Therefore, the glossiness according to the evaluation method of the present invention is very high in agreement with visual glossiness determination, has a numerical advantage, and is sufficient as an index.

Example 4
All the components and blending amounts were prepared in the same manner as in Example 1, except that 1,2-hexanediol in the ink composition of Example 1 was replaced with 4-methyl-1,2-pentanediol. Similar evaluations were made. As a result, the ink composition of Example 4 showed the same tendency as Example 1 with respect to the correlation between glossiness and visual judgment of glossiness, and the same result as the ink composition of Example 1 was obtained. .

  The present invention relates to an ink composition capable of forming a recorded image with excellent glossiness, and a method for evaluating the glossiness of a recorded image, which is substantially in agreement with human visual glossiness judgment and has an advantage as an index. As an industrial applicability.

FIG. 1 is a graph showing the relationship between the duty and glossiness of a recorded matter obtained from each ink composition according to the example. FIG. 2 is a graph showing the relationship between the duty and glossiness of a recorded matter obtained with each ink composition according to the example. FIG. 3 is a schematic diagram for explaining a method for measuring the glossiness of a recorded image. FIG. 4 is a graph showing the relationship between the reflection angle and the glossiness, and is a schematic diagram for explaining the sharpness of the recorded image.

Claims (11)

  An ink composition comprising at least a non-aqueous solvent having a surface tension of 30 mN / m or less and an organic amine of 0.1% by weight or more when dissolved in water to form a 10% by weight aqueous solution. .   The ink composition according to claim 1, wherein the non-aqueous solvent is alkanediol.   The ink composition according to claim 2, wherein the alkanediol is a 1,2-alkanediol which may have a substituent.   The ink composition according to claim 1, wherein the organic amine is a tertiary amine.   The ink composition according to any one of claims 1 to 4, further comprising a polysiloxane surfactant.   The ink composition according to any one of claims 1 to 5, wherein the coloring material of the ink is a pigment and the solid content of the pigment is 3.0% by weight or more.   The ink composition according to any one of claims 1 to 6, which forms a recorded image having a glossiness of 2.5 or more at a duty of 80%.   The ink composition according to any one of claims 1 to 6, which forms a recorded image having a glossiness of 2.5 or more at a duty of 80% of the secondary color.   The ink composition according to any one of claims 1 to 8, which forms a recorded image having a glossiness of 40 or more and a sharpness of less than 4.0 at a duty of 80%. A method for evaluating the glossiness of a recorded image, wherein the calculated value obtained by the following formula is used as an index of glossiness.
(Glossy) = (Glossiness) / (Vividness) ²
(In the formula, the glossiness is 12V50W halogen lamp as the light source, ND-10 is used as the filter, and the incident light is applied to the recorded image from the slit having the incident angle of 45 degrees and the width of 1 mm at the sensitivity of 500 and the turning angle of 0 degree. When the reflected light is reflected by the image and emitted from the slit having a width of 1.5 mm when irradiated, the light source is set so that the glossiness of the standard plate is 42.5 within a reflection angle range of 42 to 48 degrees. This is the highest value of the reflected light intensity values measured as relative values when the voltage applied to the image is adjusted.The sharpness is measured when obtaining the glossiness (maximum value of reflected light intensity). The reflected light intensity is the width of the reflection angle at which the value of the reflected light intensity is 0.6 or more under this condition, and the sharpness of the standard plate is 1.3 or more and 1.5 or less under these conditions. An apparatus for measuring glossiness of a recorded image, wherein a calculated value obtained by the following formula is automatically calculated and output as glossiness.
(Glossy) = (Glossiness) / (Vividness) ²
(In the formula, the glossiness is 12V50W halogen lamp as the light source, ND-10 is used as the filter, and the incident light is applied to the recorded image from the slit having the incident angle of 45 degrees and the width of 1 mm at the sensitivity of 500 and the turning angle of 0 degree. When the reflected light is reflected by the image and emitted from the slit having a width of 1.5 mm when irradiated, the light source is set so that the glossiness of the standard plate is 42.5 within a reflection angle range of 42 to 48 degrees. This is the highest value of the reflected light intensity values measured as relative values when the voltage applied to the image is adjusted.The sharpness is measured when obtaining the glossiness (maximum value of reflected light intensity). The reflected light intensity is the width of the reflection angle at which the value of the reflected light intensity is 0.6 or more under this condition, and the sharpness of the standard plate is 1.3 or more and 1.5 or less under these conditions.

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