Printed matter, method for recording color images, color printed matter, look-up table for use in color image recording, and white ink

Abstract

Printed matter, in which an image is recorded on a clear film with a white ink containing a white coloring material and at least one urethane resin as a resin fixative and having a degree of white shielding of 50 or more.

Claims

1. A recording method, comprising: recording an image on a clear film with a white ink containing a white coloring material and a combination of at least one urethane resin and an acrylic styrene resin as a resin fixative and having a degree of white shielding of 50 or more, an amount of the urethane resin being from 0.5% to 10% by weight of the total weight of the white ink composition, and an amount of the acrylic styrene resin being from 1% to 4% by weight of the total weight of the white ink composition, wherein the degree of white shielding is expressed by (L* value−65)/integrated transmittance×1000, with L* being L* in a L*a*b* three-dimensional space instituted by CIE and measured by a colorimeter, and L* is in the range from 0 to 100 not having units, light passing through the printed matter is measured with a spectrophotometer in a visible light region having a wavelength in the range of 380 nm to 700 nm at 1 nm intervals, measured values of the light passing through the printed matter are outputted in the form of 0% to 100%; the measured values are integrated to provide the integrated transmittance at the wavelength in the range of 380 nm to 700 nm; and the integrated transmittance ranges from 0 to 32,000, wherein 0 indicates complete shielding and 32,000 indicates complete transmission.

2. The recording method according to claim 1, wherein the at least one urethane resin is a carbonate- or ether-based aliphatic urethane resin.

3. The recording method according to claim 1, wherein the degree of white shielding is 70 or more.

4. The recording method according to claim 1, further comprising recording a color image with a color ink on the image of the clear film, wherein the color image is recorded with reference to a look-up table that corresponds to a predetermined degree of white shielding or a predetermined white ink such that a correct amount of color ink relative to the predetermined degree of white shielding or the predetermined white ink is recorded on the image.

5. The recording method according to claim 1, wherein the step of recording the image on the clear film with the white ink uses ink jet recording.

6. The recording method according to claim 1, wherein the white ink composition contains at least one material selected from the group of alkanediols and glycol ethers, and the at least one material has a content that ranges from 1 to 20% by mass of the total of the ink composition.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.

(2) FIG. 1 is a flow chart illustrating basic operations of a method for determining the degree of white shielding of printed matter according to a reference embodiment.

(3) FIG. 2 illustrates Table 1 showing representative examples, the degree of white shielding (LS value) of each of which is rated level AA, A, B, C, D, or E.

(4) FIG. 3 illustrates Table 2 showing other reference examples having the same degree of shielding (rating) B as Reference Example 2-1 shown in FIG. 2.

(5) FIG. 4 illustrates Table 3 showing another reference example having the same degree of shielding (rating) A as Reference Example 3-1 shown in FIG. 2.

(6) FIG. 5 illustrates Table 4 showing other reference examples having the same degree of shielding (rating) AA as Reference Example 4-1 shown in FIG. 2.

(7) FIG. 6 illustrates Table 5 showing the gamut volumes of Examples 1 to 4 having a degree of white shielding (LS value) of 50 or more and Comparative Examples 1 and 2 having a degree of white shielding (LS value) of less than 50.

(8) FIG. 7 is an explanatory drawing illustrating a gamut difference between Example 1 having an LS value of 53 and Comparative Example 2 having an LS value of 27.

(9) FIG. 8 is an explanatory drawing illustrating a gamut difference between examples having almost the same L-values (74.9 and 74.8) and different integrated transmittances (136 and 364).

(10) FIG. 9 is an explanatory drawing illustrating a gamut difference between examples having almost the same integrated transmittances (136 and 132) and different L-values (74.9 and 75.7).

(11) FIG. 10 is a table showing the LS value (the degree of white shielding), corresponding a- and b-values, and ODs for black (K), cyan (C), magenta (M), and yellow (Y).

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Examples

(12) As described below, measurement conditions for examples of the invention shown in Table 5 in FIG. 6 are the same as the measurement conditions for the reference embodiment. The L value was measured with a commercial colorimeter, such as GretagMacbeth Spectroscan and Spectrolino (manufactured by X-Rite Inc.), on the black backing material.

(13) In white printing, a violet chamber of a special cartridge of an ink jet printer (“PX-G930” manufactured by Seiko Epson Co.) was filled with the white ink composition. A printing test was performed with the printer on which the ink cartridge was mounted.

(14) The white ink composition was applied to Lumirror S10-100 μm (manufactured by Toray Industries, Inc.) in 1440×720 dpi resolution.

(15) The integrated transmittance of a white printed matter sample is the integrated transmittance in a visible light region (for example, a region in the range of 380 to 700 nm). The wavelength range is not limited to the above-mentioned range and may be another wavelength range in the visible light region. In that case, a correspondence between the LS value and the reference level may be different from the correspondence in the reference embodiment.

(16) As in the reference embodiment, the integrated transmittance was determined by the following method.

(17) Light passing through a white printed matter sample was measured with a spectrophotometer in the visible light region (the region in the range of 380 to 700 nm) at 1 nm intervals. The measured values were outputted in the form of 0 to 100(%).

(18) The measured values were integrated (hereinafter referred to as an integrated transmittance).

(19) The integrated transmittance ranges from 0 to 32,000, wherein 0 in complete shielding, and 32,000 indicates complete transmission.

(20) Although the spectrophotometer was used in the measurement described above, the integrated transmittance may be determined from reflectivity obtained by reflective measurement.

(21) The degree of white shielding was determined from the L* value and the integrated transmittance by the following equation.
Degree of white shielding(LS value)=(L* value−α)/integrated transmittance×1000

(22) The subtraction of α from the L* value aimed to accentuate the influence of a change in the L* value in the white region. The α is a predetermined value (in the range of 60 to 70) and was “65” in the examples.

(23) The “Gamut volume” in Table 5 in FIG. 6 refers to the gamut volume in the Lab three-dimensional space.

(24) The gamut volume was measured in the following manner.

(25) A specific of pattern composed of 400 patches was printed on the white printed matter sample with color inks. The colors of patches were measured over the entire printed matter to calculate the gamut volume in the L*a*b* three-dimensional space with an arithmetic tool. The gamut volume calculated is dimensionless.

(26) Representative examples (measurement examples) according to embodiments of the invention will be described below. FIG. 6 (Table 5) shows the gamut volumes of Examples 1 to 4 having a degree of white shielding (LS value) of 50 or more and Comparative Examples 1 and 2 having a degree of white shielding (LS value) of less than 50.

(27) In FIG. 6, titanium dioxide was used as a coloring material (there was a case where no coloring material was used), and a urethane resin (resin A: “W605” manufactured by Mitsui Chemicals Polyurethane Co., Ltd.) and resins other than urethane (resin B: an acrylic styrene resin “Joncryl 62J” manufactured by BASF and resin C: a polyethylene resin “S120” manufactured by Mitsui Chemicals, Inc.) were used as resin fixatives. Furthermore, “WBR-022U” manufactured by Taisei Fine Chemical Co., Ltd., “W635” manufactured by Mitsui Takeda chemicals, Inc., and “D-6300”, “D-6455”, and “D-2020” manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd. can be used as urethane resins. Examples of the resin other than urethane resin include acrylic styrene resins, such as “Joncryl 511”, “Joncryl 711”, and “Joncryl 7001” manufactured by BASF and polyethylene resins, such as “AQ515” manufactured by BYK Japan KK and “Hytec E-7025P” and “Hytec E-2213” manufactured by Toho Chemical Industry Co., Ltd.

(28) Comparative Example 1 in Table 5 in FIG. 6 containing no coloring material and no resin fixative (a PET recording medium alone) had no available L-value, an integrated transmittance of 16136 (light substantially passed through the recording medium), an LS value of 0, and a gamut volume of 560.

(29) An ink according to Comparative Example 2 contained 10% by mass of titanium dioxide as a coloring material, no urethane resin A, 2% by mass of each of the resin B and the resin C as resin fixatives other than urethane resin, 1% by mass of a surfactant, 2% by mass of propylene glycol, 5% by mass of 1,2-hexanediol, 2% by mass of 2-pyrrolidone, and water as the remainder.

(30) Comparative Example 2 had an L-value of 74.8, an integrated transmittance of 364, an LS value of 27, and a gamut volume of 378160.

(31) An ink according to Example 1 contained 10% by mass of titanium dioxide as a coloring material, 1% by mass of the urethane resin A and 1% by mass of each of the resin B (acrylic styrene resin) and the resin C (polyethylene resin) other than urethane resin as resin fixatives, 1% by mass of surfactant, 2% by mass of propylene glycol, 5% by mass of 1,2-hexanediol, 2% by mass of 2-pyrrolidone, and water as the remainder.

(32) Example 1 had an L-value of 75.9, an integrated transmittance of 207, an LS value of 53, and, a gamut volume of 400360.

(33) An ink according to Example 2 contained 10% by mass of titanium dioxide as a coloring material, 2% by mass of the urethane resin A and 2% by mass, of each of the resin B and the resin C other than urethane resin as resin fixatives, 1% by mass of a surfactant, 2% by mass of propylene glycol, 5% by mass of 1,2-hexanediol, 2% by mass of 2-pyrrolidone, and water as the remainder.

(34) Example 2 had an L-value of 74.9, an integrated transmittance of 136, an LS value of 73, and a gamut volume of 421936.

(35) An ink according to Example 3 contained 10% by mass of titanium dioxide as a coloring material, 2% by mass of the urethane resin A and 2% by mass of the resin B and 1% by mass of the resin C other than urethane resin as resin fixatives, 1% by mass of a surfactant, 2% by mass of propylene glycol, 5% by mass of 1,2-hexanediol, 2% by mass of 2-pyrrolidone, and water as the remainder.

(36) Example 3 had an L-value of 74.6, an integrated transmittance of 128, an LS value of 75, and a gamut volume of 424320.

(37) An ink according to Example 4 contained 10% by mass of titanium dioxide as a coloring material, 2% by mass of the urethane resin A and 4% by mass of the resin C other than urethane resin as resin fixatives, 1% by mass of a surfactant, 2% by mass of propylene glycol, 5% by mass of 1,2-hexanediol, 2% by mass of 2-pyrrolidone, and water as the remainder.

(38) Example 4 had an L-value of 75.7, an integrated transmittance of 132, an LS value of 81, and a gamut volume of 444832.

(39) A gamut difference between Example 1 having an LS value of 53 and Comparative Example 2 having an LS value of 27 will be described below with reference to FIG. 7.

(40) FIG. 7 illustrates the color reproduction areas in the ab-region partitioned at the L-values of 10, 20, 30, 40, 50, 60, 70, 80, and 90 in the Lab three-dimensional space.

(41) FIG. 7 shows that a white ink having an LS value of 53 has a wider color reproduction area than a white ink having an LS value of 27.

(42) A gamut difference between examples having almost the same L-values (74.9 and 74.8) and different integrated transmittances (136 and 364), that is, between Example having an LS value of 73 and Comparative Example 2 having an LS value of 27 will be described below with reference to FIG. 8.

(43) FIG. 8 illustrates the color reproduction areas in the ab-region partitioned at the L-values of 10, 20, 30, 40, 50, 60, 70, 80, and 90 in the Lab three-dimensional space for Example 2 having an LS value of 73 and Comparative Example 2 having an LS value of 27.

(44) FIG. 8 shows that a white ink having an LS value of 73 has a wider color reproduction area than a white ink having an LS value of 27.

(45) A gamut difference between examples having almost the same integrated transmittances (136 and 132) and different. L-values (74.9 and 75.7), that is, between Example 2 having an LS value of 73 and Example 4 having an LS value of 81 will be described below with reference to FIG. 9.

(46) FIG. 9 illustrates the color reproduction areas in the ab-region partitioned at the L-values of 10, 20, 30, 40, 50, 60, 70, 80, and 90 in the Lab three-dimensional space for Example 2 having an LS value of 73 and Example 4 having an LS value of 81.

(47) FIG. 9 shows that a white ink having an LS value of 81 has a wider color reproduction area than a white ink having an LS value of 73.

(48) The gamut examples illustrated in FIGS. 7 to 9 show that white printed matter recorded with a white ink having an LS value of 50 or more has a wide color reproduction area.

(49) Furthermore, independent of a difference between the L-values or the integrated transmittances, white printed matter recorded with a white ink having a large LS value has a wide color reproduction area.

(50) A table in FIG. 10 shows the LS value (the degree of white shielding), corresponding a- and b-values, and ODs for black (K), cyan (C), magenta (K), and yellow (Y) for Reference Example 2 and Examples 1, 2, and 4

(51) The table in FIG. 10 shows that the ODs do not vary significantly even when the LS value varies between 27 and 81. The ODs were measured with a commercial colorimeter, such as GretagMacbeth Spectroscan and Spectrolino (manufactured by X-Rite Inc.), on the black backing material.

(52) It white printing, a violet chamber of a special cartridge of an ink jet printer (“PX-G930” manufactured by Seiko Epson Co.) was filled with the white ink composition. A printing test was performed with the printer on which the ink cartridge was mounted.

(53) The white ink composition was applied to Lumirror S10-100 μm (manufactured by Toray Industries, Inc.) in 1440×720 dpi resolution. Patches were then printed with each of color inks (black (K), cyan (C), magenta (M), and yellow (Y)) on the samples to which the white ink composition was applied. The ODs of the patches were measured.

(54) In printing with the color inks in the measurement of the gamut volumes and the ODs described above, black, cyan, magenta, and yellow ink chambers of a special cartridge mounted on an ink jet printer (“PX-G930” manufactured by Seiko Epson Co.) were filled with their respective color inks. Like the white ink composition described above, the color inks used contained water as the main solvent, their respective pigments, a resin fixative, a surfactant, an organic solvent as a penetrant or a humectant, and optionally another additive agent. Such a color ink composition can be found in JP-A-2006-282822.

(55) The examples described above show that the gamut reproducible area in the printing of the color is on a white shielding layer depends on the degree of white shielding. Thus, in the recording of color images on a white base layer having a predetermined degree of white shielding, reference to a look-up table that corresponds to the degree of white shielding allows the reproduction of optimum colors for the degree of white shielding in a wide color reproduction area. The look-up table defines correspondences between image data, such as RBG, to be printed and data on the amount of ink to be applied by a printer. With reference to the look-up table, the printer obtains the data on the amount of ink and performs printing. The data on the amount of ink outputted from the look-up table cover the entire color reproduction area depending on the corresponding degree of white shielding. The data are designed such that the color image recording is performed over the entire color reproduction area depending on the corresponding degree of white shielding.

(56) The examples described above also show that the degree of white shielding varies with the white ink composition (white ink). Thus, in the recording of color images on a white shielding layer printed with a given white ink composition, reference to a look-up table that corresponds to the white ink composition allows the reproduction of optimum colors for the white ink composition in a wide color reproduction area. The data on the amount of ink outputted from the look-up table cover the entire color reproduction area depending on the corresponding white ink. The data are designed such that the color image recording is performed aver the entire color reproduction area depending on the corresponding white ink. Thus, even when the same image data are inputted to look-up tables, the look-up tables in which the corresponding degrees of white shielding or white inks are different can output different data on the amount of ink.