JP2005305879A - Ink cartridge and method of inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a united ink cartridge whereby inks of red and blue can be consumed in a pace the same as that of the other color, and a method of inkjet recording using the cartridge. <P>SOLUTION: This ink cartridge is filled with at least an ink of red or blue and inks of the other colors, and the quantity of the ink of red or blue is smaller than that of ink of the other color. The upper limits of the amounts of the red ink and the blue ink are represented by the following formulas. The formula 1 is as follows: the upper limit of the amount of filled red ink=(the maximum chroma saturation of ink of the other color/the maximum chroma saturation of the red ink)×the amount of filled ink of the other color. The formula 2 is as follows: the upper limit of the amount of filled blue ink=(the maximum chroma saturation of ink of the other color/the maximum chroma saturation of the blue ink)×the amount of ink of the other color×1.1. A character and/or an image is formed on a recording medium by a printer using the above ink cartridge. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink cartridge and an ink jet recording method, and more particularly to an integrated ink cartridge filled with a plurality of hue inks in addition to a red ink and a blue ink, and an ink jet recording method using the same.

In recent years, the number of pixels of a digital camera has been improved, and the image quality obtained by a digital camera has become close to that of a silver halide photograph, although it depends on the subject.
An image taken with a digital camera can be immediately confirmed on the display of the camera body immediately after shooting. As a result, unnecessary photographed images can be erased on the spot, and there is no need to go through a development process unlike silver halide photography.
In parallel with this, as a color printer for outputting a photographed image by a digital camera, an inkjet recording system for general users is widely used.

In addition, image information captured by a digital camera can be directly output by an output device such as an ink jet printer without being processed by an information device such as a computer.
In view of the above, digital cameras and inkjet printers have been recognized as simple photographic image recording and output means.
However, there are some users who want more convenience for digital cameras and inkjet printers.

For ink jet printers, there is a demand for further ease of ink cartridge replacement.
A color printer uses a plurality of hue inks. Usually, the ink to be used is individually filled in the cartridge. In the process of using the color printer, when the ink of a certain hue is used up, it is replenished by replacing the ink cartridge of the lost hue each time.
However, shortly after replacing an ink cartridge of a certain hue, the ink of another hue disappears repeatedly, which may cause annoyance.
Therefore, handling is improved by using an integrated ink cartridge in which a plurality of hue inks are filled in one cartridge and reducing the frequency of ink cartridge replacement work.

  Further, among ink sets that have been used in color printers, conventional general ink sets are combinations of cyan, magenta, yellow, and black, and further include light cyan and light magenta. However, in recent years, in order to further expand color reproduction, a combination of red and blue inks is used instead of light cyan and light magenta.

  However, red and blue are generally high in saturation but low in lightness. For this reason, in normal use, red and blue inks tend to use less than inks of other colors such as cyan, magenta, yellow, and black. Therefore, if the same amount of ink of other colors such as red, blue, cyan, magenta, yellow, and black is filled in the integrated ink cartridge, red and blue inks remain compared to other colors. It becomes. In short, although the red and blue inks still remain, the ink cartridge must be replaced, and the red and blue inks are wasted. Therefore, it has been required to reduce the remaining amount of red and blue ink when any one of the inks reaches the ink end.

On the other hand, Patent Document 1 discloses that an ink cartridge using cyan, light cyan, magenta, light magenta, yellow, and black inks is filled with more yellow ink than other color inks. This is because, when printing an image, cyan and light cyan are used depending on the density in the cyan area, and magenta and light magenta are used depending on the density in the magenta area. Therefore, because the amount of ink used is larger than cyan, light cyan, magenta, and light magenta, the initial filling amount of yellow ink has to be larger than the initial filling amount of other color inks. is there.
However, this Patent Document 1 does not disclose the use of red and blue inks, and from this Patent Document 1, it is impossible to determine the initial filling amount of an integrated cartridge of red and blue inks. Met.

Japanese Patent No. 3120739

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. When any one of the inks reaches the ink end, the remaining amount of red and blue ink is small, and an ink jet using the integrated ink cartridge An object is to provide a recording method.

As a result of intensive studies, the present inventor has achieved the above object by adopting the following configuration, and has achieved the present invention.
That is, the present invention is as follows.

(1) An ink cartridge filled with at least each ink of red or blue and other hue, wherein the filling amount of ink of red or blue is smaller than the filling amount of each ink of other hue cartridge.
(2) The ink cartridge according to (1), wherein the inks of other hues are yellow ink, magenta ink, and cyan ink.

(3) The ink cartridge according to (1), wherein an upper limit of a filling amount of the red ink is as follows.

(Equation 1)
Upper limit of red ink filling amount = (maximum saturation of ink of other hues / maximum saturation of red ink)
× Filling amount of ink of other colors

(However, the maximum saturation is the maximum value of the saturation C ^* defined in the CIELAB color space when a plurality of color patches with an ink ejection amount of 14 mg / inch ² or less and different ink ejection amounts are output to the recording medium. .)

(4) The ink cartridge according to (3), wherein the ink of the other hue is magenta ink.

(5) The ink cartridge according to claim 1, wherein the upper limit of the blue ink filling amount is expressed by the following formula.

(Equation 2)
Upper limit of blue ink filling amount = (maximum saturation of ink of other hues / maximum saturation of blue ink)
× Filling amount of ink of other hues × 1.1

(However, the maximum saturation is the maximum value of the saturation C ^* defined in the CIELAB color space when a plurality of color patches are output on the recording medium with the ink injection amount being 14 mg / inch ² or less and the ink injection amount being changed. )

(6) The ink cartridge according to (5), wherein the ink of the other hue is a cyan ink.

(7) An ink jet recording method in which characters and / or images are formed on a recording medium by a printing apparatus using the ink cartridge of (1) to (6).

  In the ink cartridge of the present invention, the filling amount of red or blue ink is smaller than the filling amount of each ink of other hues, and therefore, when replacing the ink cartridge, the red and blue inks are not completely consumed and are wasted. It ’s gone.

In addition, the ink cartridge of the present invention may be any ink as long as the filling amount of red or blue ink is smaller than the filling amount of each ink of other hues. More suitably, the ink cartridge is filled with red ink and blue ink. The upper limit of the amount is calculated from the relationship between the maximum saturation of those inks and the maximum saturation of inks of other hues.
That is, it is preferable that the upper limit of the filling amount of the red ink and the blue ink is as follows.

(Equation 3)
Upper limit of red ink filling amount = (maximum saturation of ink of other hues / maximum saturation of red ink)
× Filling amount of ink of other colors

(Equation 4)
Upper limit of blue ink filling amount = (maximum saturation of ink of other hues / maximum saturation of blue ink)
× Filling amount of ink of other hues × 1.1

(However, the maximum saturation is the maximum value of the saturation C ^* defined in the CIELAB color space when a plurality of color patches with an ink ejection amount of 14 mg / inch ² or less and different ink ejection amounts are output to the recording medium. .)

The relationship between the above equations will be described in more detail below.
The maximum saturation of red and blue is higher than that of cyan and magenta.
For example, FIG. 4 shows an a * -b * plane image of the CIELAB color system.
Saturation is expressed by the distance from the intersection of the a * axis and b * axis in FIG. 4, but the maximum saturation of red and blue is in a higher saturation region than cyan and magenta.

Therefore, by dividing the maximum saturation value of the other hue by the maximum saturation value of red or blue, and multiplying that value by the ink filling amount value of the other hue, the red or blue ink filling amount is calculated. You can get an upper bound.
However, the maximum saturation is the maximum value of the saturation C ^* defined in the CIELAB color space when a plurality of color patches with different ink ejection amounts of 14 mg / inch ² or less are output to the recording medium.
For example, in the case of blue ink, if the density in the recording medium is increased, the saturation increases up to a certain point. This is because adding more than that may lower the saturation.
By specifying the maximum saturation, the upper limit of the filling amount of the red ink or the blue ink can be specified by a general formula regardless of the color material density in the ink.

As for the upper limit of the red ink filling amount, the maximum saturation value of the red ink is divided by the maximum saturation value of the red ink, and the value is multiplied by the ink filling amount value of the other hue. Although it is sufficient, the upper limit of the blue ink filling amount is determined by dividing the maximum saturation value of the ink of another hue by the maximum saturation value of the blue ink and filling that value with the ink saturation of the other hue. Multiply the quantity value, and then multiply by a factor of 1.1.
The reason for this is that the blue color has a lower lightness than the red color, so that a factor of 1.1 is multiplied to compensate for the low lightness. In other words, in a color standard such as JAPAN COLOR, the solid color of blue has a lower lightness than the solid color of red, and therefore the proportion of blue ink used tends to be higher than that of red ink.

From the above, the upper limit of the filling amount of red and blue ink can be obtained,
In the ink cartridge of the present invention, as long as the red and blue inks are less than or equal to the upper limit of the filling amount, only red or blue ink does not remain by printing, and is not wasted when the cartridge is replaced. However, if the filling amount of red and blue inks is too small, there also arises a problem that the red and blue inks disappear before inks of other hues such as cyan, magenta, and yellow.
Therefore, it is preferable to set the lower limit of the filling amount of red and blue ink.
The lower limit of the filling amount of red and blue inks is such that the red and blue inks do not disappear before inks of other hues even if the color used for the printed material varies greatly. However, in applications in which portrait images are mainly output, the filling amount of red or blue ink is preferably 40% or more of the filling amount of magenta or cyan ink.
More suitably, the amount represented by the following formula is preferred.

(Equation 5)
Lower limit of red ink filling amount = (maximum saturation of ink of other hues / maximum saturation of red ink)
× Filling amount of ink of other hues × 0.9

(Equation 6)
Lower limit of blue ink filling amount = (maximum saturation of ink of other hues / maximum saturation of blue ink)
× Filling amount of ink of other colors

For the lower limit of the red ink filling amount, the maximum saturation value of the red ink is divided by the highest saturation value of the red ink, and the value is multiplied by the ink filling amount value of the other hue. For the lower limit of the blue ink filling amount, the maximum saturation value of the blue ink is divided by the maximum saturation value of the ink of the other hues, and the other saturation value is multiplied by the other value. It is sufficient to multiply the hue ink fill value.
The reason for this is that, as in the above-described determination of the upper limit, the lightness of blue is lower than that of red, so the red color is multiplied by a factor of 0.9 and the blue color is not multiplied. In other words, in a color standard such as JAPAN COLOR, the solid color of blue has a lower lightness than the solid color of red, and therefore the proportion of blue ink used tends to be higher than that of red ink.

  In order to calculate the upper limit and the lower limit of the filling amount of the red and blue ink cartridges described above, the maximum saturation value and the filling amount value of the inks of other hues can be used as the index. The other hue at that time is not particularly limited. However, when the upper limit and the lower limit of the red ink filling amount are to be obtained, it is possible to select the magenta color as the other hue. When obtaining the lower limit, it is preferable to select cyan as the other hue.

Hereinafter, the ink cartridge of the present invention will be described in detail.
The ink cartridge according to the present invention is filled with at least each ink of red or blue and other hues, and the filling amount of each ink of red or blue is smaller than the filling amount of each ink of other hues If it is, it will not specifically limit about another form, For example, what is shown in FIGS. 1-3 is mentioned.

  As shown in FIGS. 1 and 2, the ink cartridge 14 has a substantially rectangular parallelepiped shape. The ink cartridge 14 includes a storage case 31 including a case main body 32 and a lid 33, and a plurality of ink packs 34 (see FIG. 3) stored in the liquid storage case 31.

  As shown in FIG. 3, the ink pack 34 includes a bag portion 41 and an ink outlet member 42. The bag portion 41 is formed of a flexible material, and is formed of, for example, an aluminum laminate film having a structure in which the outside is sandwiched between a nylon film and the inside is sandwiched between polyethylene films in order to improve gas barrier properties. The bag portion 41 is formed by stacking these two substantially rectangular aluminum laminate films and bonding the periphery thereof by a method such as heat welding, and stores ink therein.

  The ink lead-out member 42 has a substantially cylindrical shape made of, for example, plastic, and the inside thereof forms an ink supply port 42a. Then, the ink stored in the ink pack 34 is taken out through the ink supply port 42a. Further, the ink supply port 42a is provided with a valve mechanism (not shown) that is opened only when ink is supplied, so that the ink in the bag portion 41 does not leak.

  As shown in FIGS. 1 and 2, the housing case 31 includes a substantially box-shaped case main body 32 having an opening in the upper portion and a substantially plate-shaped lid portion 33 that covers the opening of the case main body 32. . At the center of the front surface of the storage case 31 (the front surface of the case main body 32) 32a, for example, six support portions 43, which are the same as the number of ink packs 34 to be stored, are provided. The six support portions 43 are arranged side by side so that their centers are positioned on a center line L1 parallel to the bottom surface (the bottom surface of the case main body 32) 32c of the housing case 31, and are approximately centered in the vertical direction of the case main body 32. Each is provided.

  Further, as shown in FIG. 3, these support parts 43 are provided with a lower support part 43a constituting the lower half of the case body 32 and an upper support part 43b constituting the upper half of the cover part 33. Yes. The support portion 43 supports the ink lead-out member 42 of each ink pack 34. Therefore, when the lid portion 33 is attached in a state where the ink lead-out member 42 of the ink pack 34 is supported by the lower support portion 43a of the case body 32, the support portion 43 has the lower and upper support portions 43a and 43b. The support part 43 is comprised by aligning. The six support portions 43 are equally spaced, and the ink packs 34 supported by the support portions 43 are arranged so as to overlap at equal intervals.

Further, two positioning holes 51 are provided on the front surface 32a of the case body 32 in the vicinity of both end portions thereof. Further, as shown in FIG. 3, an engagement hole 53 for engaging with the lid portion 33 is provided on the back surface 32 b of the case main body 32.
In the above embodiment, six ink packs 34 are stored, but the number is not particularly limited. For example, 3-5 pieces or 7 pieces or more may be sufficient.

Next, the ink filled in the ink cartridge of the present invention will be described.
The red ink filled in the ink cartridge of the present invention is an ink having a hue angle ∠H ° defined in the CIELAB color space on the recording medium in the range of about 0 to about 80 °. The hue angle ∠H ° is ∠H ° = tan ⁻¹ (b ^* / a ^* ) + 180 (when a ^* <0) or 、 H ° = tan ⁻¹ (b ^* / a ^* ) + 360 (a ^* If> 0). a ^* and b ^* represent the perceptual chromaticity index defined in the CIELAB color space.

  The blue ink filled in the ink cartridge of the present invention is an ink having a hue angle ∠H ° defined in the CIELAB color space on the recording medium in the range of about 260 to about 330 °.

Further, the inks of other hues other than red and blue filled in the ink cartridge of the present invention are not particularly limited, and examples thereof include yellow ink, magenta ink, cyan ink, and black ink.
As the three color inks of yellow, magenta and cyan, subtractive mixed primary color inks usually used in this type of ink set can be used.

  As the color material contained in the ink according to the present embodiment, a dye, an inorganic pigment, and an organic pigment can be used, and each can be used alone or in combination. As the inorganic pigment, for example, in addition to titanium oxide and iron oxide, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can be used. Examples of the organic pigment include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (eg, 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 chelate, acidic dye chelate, etc.), nitro pigments, nitroso pigments, aniline black, and the like. Specific examples include the following pigments.

  Examples of the pigment contained in the red ink include C.I. I. Pigment Orange 5, 43 and 62 and C.I. I. It is preferable to use 1 type (s) or 2 or more types selected from the group consisting of CI Pigment Red 17, 49: 2, 112, 149, 177, 178, 188, 255 and 264. Of these, C.I. I. Pigment orange 43 and C.I. I. It is preferable to use one or more selected from the group consisting of CI Pigment Red 149, 177, 178 and 264. In this case, the red ink has a lightness of “a color that can be formed with a single red ink” and “a color that has the same hue angle and saturation formed by mixing only two colors of yellow ink and magenta ink”. The graininess and gloss can be improved as much as possible.

  Examples of the pigment contained in the blue ink include C.I. I. Pigment blue 60 and C.I. I. It is preferable to use one or more selected from the group consisting of CI Pigment Violet 3, 19, 23, 32, 36 and 38. Of these, C.I. I. Pigment blue 60 and C.I. I. It is preferable to use one or more selected from the group consisting of CI Pigment Violet 19 and 23. In this case, the brightness of the blue ink is close to that of “a color that can be formed by a single blue ink” and “a color that has the same hue angle and saturation formed by mixing only two colors of cyan ink and magenta ink”. The graininess and gloss can be improved as much as possible.

  Examples of the pigment contained in the yellow ink include C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 128, 129, 138, 139, 147, 150, 151, 154, 155, 180, 185 and the like, and one or more of these are used. Of these, C.I. I. It is preferable to use one or more selected from the group consisting of CI Pigment Yellow 74, 110, 128 and 147.

  Examples of the pigment contained in the magenta ink include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 112, 122, 123, 168, 184, 202, 209; I. Pigment violet 19 and the like, and one or more of these may be used. Of these, C.I. I. Pigment red 122, 202, 209 and C.I. I. It is preferable to use one or more selected from the group consisting of CI Pigment Violet 19.

  Examples of the pigment contained in the cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15: 3, 15: 4, 15:34, 16, 22, 60; I. Bat Blue 4, 60 etc. are mentioned, These 1 type or 2 types or more are used. Of these, C.I. I. CI Pigment Blue 15: 3 and / or 15: 4 are preferably used. I. Pigment Blue 15: 3 is preferably used.

  The content of each pigment in each of the red ink and the blue ink (in terms of solid content, the same applies hereinafter) is based on the total weight of the ink from the viewpoint of the balance between the print density and the reliability as an inkjet recording ink. , Preferably 2 to 6% by weight, more preferably 2 to 4% by weight.

  In addition, the content of each pigment in the yellow, magenta, and cyan inks is preferably 0.1 to 2% by weight with respect to the total weight of the ink, respectively, from the viewpoint of glossiness and saturation. More preferably, it is 1.5 to 2% by weight.

  In the present invention, as another preferred embodiment, from the viewpoint of improving dot visibility (granularity) on an inkjet-dedicated recording medium having an ink absorbing layer, the content of each pigment in the magenta ink and cyan ink Is 2% by weight or less, particularly 0.1 to 2% by weight, especially 1.5 to 2% by weight, and the pigment content of each of the red ink, blue ink and yellow ink is 2% by weight or more. 2 to 6% by weight, especially 2 to 4% by weight.

  In the present invention, as another preferred embodiment, from the viewpoint of expansion of the color reproduction range on plain paper and color development, the pigments of the yellow ink, magenta ink, cyan ink, red ink and blue ink are used. The content is 2% by weight or more.

  The ink cartridge of this embodiment includes red, blue, yellow, magenta, and cyan inks, but black ink can be further added as necessary. Examples of the pigment contained in the black ink include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, and channel black, inorganic pigments such as iron oxide pigments; aniline black (C And organic pigments such as I. Pigment Black 1). It is particularly preferable to use carbon black, and examples of preferable carbon black include No. 2300, No. 900, MCF 88, No. 33, No. 40, No. 52, MA7, MA8, MA100, No. 2200B, Colombian Raven5750, Raven5250, Raven5000, Raven3500, Raven1255, Raven700 etc., Cabot Regal 400R, Regal 400R, Regal 1660R, Mogul 1, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000 Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex 35, Printex, manufactured by Tegussa Co., Ltd., Monarch 1100, Monarch 1300, Monarch 1400, etc. U, Printex V, Printex 140U, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 and so on. Further, the content of the pigment in the black ink is preferably 0.1 to 4% by weight, more preferably 1 to 3% by weight.

  The ink according to this embodiment preferably contains a dispersant from the viewpoint of improving the dispersion stability of 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 ester copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, styrene- 、 | methylstyrene-acrylic acid copolymer Styrene- ス チ レ ン | methylstyrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-maleic acid copolymer, vinylnaphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinylethylene Copolymer, vinyl acetate-maleic ester Polymers, vinyl acetate - crotonic acid copolymer, vinyl acetate - acrylic acid copolymer 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. The dispersant is contained in the ink in an amount of preferably 0.1 to 10% by weight, more preferably 0.3 to 6% by weight, in terms of solid content, with respect to the pigment.

  In addition, the ink according to the present embodiment can contain a high boiling point organic solvent from the viewpoint of preventing the ink from drying and preventing clogging in the head of the ink jet printer. Examples of the high boiling point organic solvent 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. Polyhydric alcohols such as ethane and trimethylolpropane; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tri Multivalent such as ethylene glycol monobutyl ether Alkyl ethers of alcohol; saccharides such as urea, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine, sugar alcohol, etc., and one of these Or 2 or more types are used. The high-boiling organic solvent is preferably contained in the ink in an amount of 0.1 to 30% by weight, more preferably 0.5 to 20% by weight.

  Further, the ink according to the present embodiment can contain a low boiling point organic solvent from the viewpoint of shortening the drying time of the ink. Examples of the low boiling point organic solvent include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, sec-butanol, tert-butanol, iso-butanol, n-pentanol, and the like. 1 type (s) or 2 or more types are used. In particular, monohydric alcohol is preferable.

  Further, the ink according to the present embodiment can contain a penetration accelerator from the viewpoint of increasing the wettability to the recording medium and increasing the permeability. Examples of the penetration enhancer include various surfactants such as anionic surfactant, cationic surfactant and amphoteric surfactant; alcohols such as methanol, ethanol and iso-propyl alcohol; ethylene glycol monomethyl ether, diethylene glycol Lower alkyl ethers of polyhydric alcohols such as monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether; diols such as 1,2-pentanediol and 1,2-hexanediol Etc., and one or more of these are used. In particular, it is preferable to use diethylene glycol monobutyl ether, triethylene glycol monobutyl ether or 1,2-hexanediol. The penetration enhancer is preferably contained in the ink in an amount of 1 to 20% by weight, more preferably 1 to 10% by weight.

  As the penetration accelerator, an acetylene glycol compound or a polysiloxane compound represented by the following general formula (I) can also be used. Commercially available compounds can be used as the acetylene glycol compounds, such as Olphine Y, Surfynol 82, 440, 465, 485, STG, E1010 (all trade names, Air Products and -Chemicals) etc. are mentioned, These 1 type (s) or 2 or more types are used. In particular, Surfynol 465 is preferably used. Moreover, as this polysiloxane type compound, BYK348 (made by Big Chemie Japan) etc. can be used as a commercial item. The acetylene glycol compound and / or the polysiloxane compound is preferably contained in the ink in an amount of 0.1 to 5% by weight, more preferably 0.5 to 2% by weight.

  In addition to the pigment, the ink according to the present embodiment contains a dispersant, a high-boiling organic solvent, a low-boiling organic solvent, and a penetration accelerator as necessary, and water as a balance. 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.

  If necessary, the ink according to the present embodiment 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. Additives such as oxygen absorbers and pH adjusters can be contained, and one or more of these can be used.

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

  The ink cartridge of the present embodiment is preferably used in an ink jet recording method which is a recording method in which ink droplets are ejected from nozzles and adhered to a recording medium to form characters and / or images. In particular, it is preferably used for an on-demand type ink jet recording method. As an on-demand type ink jet recording method, for example, a piezoelectric element recording method for recording using a piezoelectric element disposed in a printer head, or a heat energy by a heater of a heating resistance element disposed in the printer head is used. And a thermal jet recording method for recording, and can be suitably used for any ink jet recording method.

The present invention will be described more specifically with reference to the following examples. However, the scope of the present invention is not limited to these examples.
[Manufacture of ink cartridges]
Each ink of yellow, magenta, cyan, red, blue, and black was manufactured according to the composition shown in Table 1, and individually injected into the ink pack 34 shown in FIG. The injection amount is as shown in Tables 2 and 3. The unit in Table 1 is% by weight, and the remaining amount is ion-exchanged water, which is 100% by weight as a whole.

  As shown in FIGS. 1 to 3, the ink pack 34 into which the ink was injected was stored in the storage case 31 to manufacture the ink cartridge 14.

[Printing test]
The printing test was performed with an ink jet printer modified based on PM-G900X manufactured by Seiko Epson Corporation so that ink could be supplied from the ink cartridge to the head via a tube. After the ink was filled in the head, a pattern of S6RGB (JIS X9204) was continuously printed on photographic paper <gloss> manufactured by Seiko Epson Corporation until any one color of ink disappeared. Tables 2 and 3 show the remaining amount of ink at the end of printing.

  The ink cartridge of the example has an ink remaining amount (total amount) of 22.0 g, whereas the ink remaining amount (total amount) of the comparative example is 26.8 g. The ink cartridge of the example was able to reduce the remaining ink amount by 6.8 g (31%) compared to the ink cartridge of the comparative example.

FIG. 3 is a perspective view of the ink cartridge from above. FIG. 3 is a perspective view of the ink cartridge from below. FIG. 3 is an exploded perspective view of an ink cartridge. The image figure of the a * -b * plane of CIELAB color system.

Explanation of symbols

14 Ink Cartridge, 31 Storage Case, 32 Case Body, 32a Case Body Front, 32c Bottom, 33 Lid, 34 Ink Pack, 42a Ink Supply Port, 43 Support, 51 Positioning Hole

Claims (7)

  An ink cartridge filled with at least each ink of red or blue and other hues, wherein an ink filling amount of red or blue ink is smaller than a filling amount of each ink of other hues. 2. The ink cartridge according to claim 1, wherein the other hue inks are yellow ink, magenta ink, and cyan ink. 2. The ink cartridge according to claim 1, wherein the upper limit of the filling amount of red ink is represented by the following formula.
(Equation 1)
Upper limit of red ink filling amount = (maximum saturation of ink of other hues / maximum saturation of red ink)
× Filling amount of ink of other colors

(However, the maximum saturation is the maximum value of the saturation C ^* defined in the CIELAB color space when a plurality of color patches with an ink ejection amount of 14 mg / inch ² or less and different ink ejection amounts are output to the recording medium. .)   4. The ink cartridge according to claim 3, wherein the ink having the other hue is magenta ink. 2. The ink cartridge according to claim 1, wherein the upper limit of the blue ink filling amount is as follows.
(Equation 2)
Upper limit of blue ink filling amount = (maximum saturation of ink of other hues / maximum saturation of blue ink)
× Filling amount of ink of other hues × 1.1

(However, the maximum saturation is the maximum value of the saturation C ^* defined in the CIELAB color space when a plurality of color patches are output on the recording medium with the ink injection amount being 14 mg / inch ² or less and the ink injection amount being changed. )   6. The ink cartridge according to claim 5, wherein the ink of another hue is a cyan ink. An ink jet recording method for forming characters and / or images on a recording medium by a printing apparatus using the ink cartridge according to claim 1.

Images