Aqueous Ink and Aqueous Dye Dispersion for Aqueous Ink

Abstract

An aqueous dye dispersion for an aqueous ink including a dye derivative as indicated at Formula (1) below; a water-insoluble dye; a dispersant; and water, makes it possible to provide an aqueous dye dispersion for aqueous ink, which reduces flocculation of particles within aqueous ink even when the aqueous ink is prepared, and has satisfactory dispersion stability during storage, thereby providing an aqueous ink having satisfactory dispersion stability during storage.

##STR00001##

(At Formula (1), R.sup.1 is a group as indicated at Formula (2), below, and R.sup.2 is a group as indicated at Formula (3), below. m and n are each 0 or 1 but m+n=1. R.sup.3 is at least one species selected from among a hydroxyl group and an amino group. l is 0 to 2; when l=2, R.sup.3 may respectively be the same or different.)

##STR00002##

(At Formula (3), R.sup.4 is a phenylene group or an alkylene group having 1 to 4 carbons; R.sup.5 and R.sup.6 are independently selected alkyl groups having 1 to 4 carbons.)

Claims

1. An aqueous dye dispersion for an aqueous ink, comprising: a dye derivative as indicated at Formula (1) below; a water-insoluble dye; a dispersant; and water; wherein Formula (1) is given by ##STR00008## wherein, at Formula (1), R.sup.1 is a group as indicated at Formula (2) below; R.sup.2 is a group as indicated at Formula (3) below; m and n are each 0 or 1 but m+n=1; R.sup.3 is at least one species selected from among a hydroxyl group and an amino group; l is 0 to 2; and when l=2, R.sup.3 is respectively the same or different; wherein Formula (2) is given by ##STR00009## wherein Formula (3) is given by ##STR00010## wherein, at Formula (3), R.sup.4 is a phenylene group or an alkylene group having 1 to 4 carbons; and R.sup.5 and R.sup.6 are independently selected alkyl groups having 1 to 4 carbons.

2. The aqueous dye dispersion for the aqueous ink according to claim 1, wherein the dye derivative as indicated at Formula (1) above, is a dye derivative as indicated at Formula (4) below; wherein Formula (4) is given by ##STR00011## wherein, at Formula (4), R.sup.1 is a group as indicated at Formula (2) above; R.sup.2 is a group as indicated at Formula (3) above; and m and n are each 0 or 1 but m+n=1.

3. An aqueous ink comprising: the aqueous dye dispersion for the aqueous ink according to claim 1; and a surfactant.

4. The aqueous ink according to claim 3 which is for inkjet recording.

Description

EXAMPLES

[0100] Hereinafter, embodiments of the present invention are described in more specific terms with reference to examples.

Manufacturing Example 1: Manufacture of Dye Derivative a

[0101] 504 parts by weight of concentrated sulfuric acid and 400 parts by weight of 28% fuming sulfuric acid were mixed, 66.26 parts by weight of C. I. Disperse Red 60 (KP PLAST Red B manufactured by Kiwa Chemical Industry Co., Ltd.; hereinafter referred to as PLAST Red B) was mixed thereinto in such fashion as to not exceed 30 C., and was reacted with being stirred for 3 hours at 30 C. The reaction liquid obtained was discharged into a large volume of icewater and allowed to crystallize. The crystals obtained were separated by filtration and were thereafter washed in pure water and dried at 80 C. to obtain 51.7 parts by weight of Dye Derivative a. Identification of the chemical structure of the obtained Dye Derivative a was carried out using an AXIMA-CFR plus matrix-assisted laser desorption ionization/time-of-flight mass spectrometer (MALDI-TOF-MS) manufactured by Shimadzu Corporation in positive ion mode with an -cyano-4-hydroxycinnamic acid (CHCA) matrix. As a result, a molecular ion peak was observed at m/z=411. This value agrees with the monoisotopic mass corresponding to the situation that exists at Formula (1) when m is 1, n is 0, R.sup.1 is at position 3 at Formula (1), and the hydroxyl group and NH.sub.2 of R.sup.3 are respectively at positions 1 and 4 at Formula (1).

Manufacturing Example 2: Manufacture of Dye Derivative b

[0102] 500 parts by weight of chlorosulfonic acid was cooled in an ice bath to a temperature not higher than 10 C., 66.26 parts by weight of PLAST Red B was mixed thereinto in such fashion as to not exceed 30 C., and was reacted with being stirred for 2 hours at 30 C. The reaction liquid obtained was discharged into a large volume of icewater and allowed to crystallize. The crystals obtained were separated by filtration and were thereafter washed in pure water to obtain a reddish brown aqueous paste. This was dispersed in 2000 parts by weight of cold water, was mixed with 78.14 parts by weight of diethylaminopropylamine at a temperature not higher than 10 C., and was reacted with being stirred for 3 hours at 10 to 20 C. The reaction liquid obtained was separated by filtration, was further washed in cold pure water, and was dried at 80 C. to obtain 98.5 parts by weight of Dye Derivative b.

[0103] Furthermore, upon performing identification of the chemical structure of Pigment Derivative b in the same manner as at Manufacturing Example 1, a molecular ion peak was observed at m/z=524. This value agrees with the monoisotopic mass corresponding to the situation that exists at Formula (1) when m is 0, n is 1, R.sup.2 is at position 3 at Formula (1), the hydroxyl group and NH.sub.2 of R.sup.3 are respectively at positions 1 and 4 at Formula (1), and, at Formula (3), R.sup.4 is an alkylene group having 3 carbons (trimethylene group), and R.sup.5 and R.sup.6 are alkyl groups having 2 carbons (ethylene group).

Example 1

[0104] 15 parts by weight of PLAST Red B serving as water-insoluble dye, 1 part by weight of Dye Derivative a obtained at Manufacturing Example 1, 22.5 parts by weight of resin-type dispersant (DISPERBYK-190; manufactured by BYK-Chemie; 40 wt % solids content; acid-value-type dispersant having an acid value of 10 mgKOH/g), 61.5 parts by weight of deionized water, and 460 parts by weight of zirconia beads of diameter 0.3 mm were placed in a sand mill, and dispersion was carried out at 1500 rpm for 15 hours. The zirconia beads were thereafter removed to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 2, and the content amount of disperse dye has been adjusted so as to be 15 wt %.

Example 2

[0105] Except for the fact that 9 parts by weight of EFKA PX4701 (manufactured by BASF; 100 wt % resin content; amine-number-type dispersant having amine number of 40 mgKOH/g) serving as resin-type dispersant was used instead of 22.5 parts by weight of DISPERBYK-190, and 75 parts by weight of deionized water was used instead of 61.5 parts by weight thereof, the same procedure as at Example 1 was used to obtain an aqueous dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 2.

Example 3

[0106] Except for the fact that surface-active-agent-type dispersants in the form of 9 parts by weight of Demol SN-B (manufactured by Kao Corporation; 95 wt % effective ingredient content; anionic) and 2 parts by weight of NIKKOL BPS-30 (manufactured by Nikko Chemicals Co., Ltd.; 100 wt % solids content; nonionic) were used instead of 22.5 parts by weight of resin-type dispersant in the form of DISPERBYK-190, and 73 parts by weight of deionized water was used instead of 61.5 parts by weight thereof, the same procedure as at Example 1 was used to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 2.

Example 4

[0107] Except for the fact that Dye Derivative b from Manufacturing Example 2 was used instead of Dye Derivative a from Manufacturing Example 1, the same procedure as at Example 1 was used to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 2.

Example 5

[0108] Except for the fact that 9 parts by weight of EFKA PX4701 (manufactured by BASF; 100 wt % resin content) serving as resin-type dispersant was used instead of 22.5 parts by weight of DISPERBYK-190, and 75 parts by weight of deionized water was used instead of 61.5 parts by weight thereof, the same procedure as at Example 4 was used to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 2.

Example 6

[0109] Except for the fact that surface-active-agent-type dispersants in the form of 9 parts by weight of Demol SN-B (manufactured by Kao Corporation; 95 wt % effective ingredient content) and 2 parts by weight of NIKKOL BPS-30 (manufactured by Nikko Chemicals Co., Ltd.; 100 wt % solids content) were used instead of 22.5 parts by weight of resin-type dispersant in the form of DISPERBYK-190, and 73 parts by weight of deionized water was used instead of 61.5 parts by weight thereof, the same procedure as at Example 4 was used to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 2.

Comparative Example 1

[0110] Except for the fact that no dye derivative was used instead of 1 part by weight of Dye Derivative a, and 62.5 parts by weight of deionized water was used instead of 61.5 parts by weight of deionized water, the same procedure as at Example 1 was used to prepare a dye dispersion. The composition of this dye dispersion was as indicated at TABLE 2.

Example 7

[0111] Except for the fact that C. I. Disperse Yellow 54 was used instead of C. I. Disperse Red 60 as disperse dye, the same procedure as at Example 1 was used to prepare a dye dispersion. The composition of this dye dispersion was as indicated at TABLE 3.

Example 8

[0112] Except for the fact that surface-active-agent-type dispersants in the form of 9 parts by weight of Demol SN-B and 2 parts by weight of NIKKOL BPS-30 were used instead of 22.5 parts by weight of resin-type dispersant in the form of DISPERBYK-190, and 73 parts by weight of deionized water was used instead of 61.5 parts by weight thereof, the same procedure as at Example 7 was used to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 3.

Example 9

[0113] Except for the fact that Dye Derivative b from Manufacturing Example 2 was used instead of Dye Derivative a from Manufacturing Example 1, the same procedure as at Example 7 was used to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 3.

Example 10

[0114] Except for the fact that surface-active-agent-type dispersants in the form of 9 parts by weight of Demol SN-B and 2 parts by weight of NIKKOL BPS-30 were used instead of 22.5 parts by weight of resin-type dispersant in the form of DISPERBYK-190, and 73 parts by weight of deionized water was used instead of 61.5 parts by weight thereof, the same procedure as at Example 9 was used to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 3.

Example 11

[0115] Except for the fact that C. I. Disperse Blue 359 was used instead of C. I. Disperse Red 60 as disperse dye, the same procedure as at Example 1 was used to prepare a dye dispersion. The composition of this dye dispersion was as indicated at TABLE 3.

Example 12

[0116] Except for the fact that surface-active-agent-type dispersants in the form of 9 parts by weight of Demol SN-B and 2 parts by weight of NIKKOL BPS-30 were used instead of 22.5 parts by weight of resin-type dispersant in the form of DISPERBYK-190, and 73 parts by weight of deionized water was used instead of 61.5 parts by weight thereof, the same procedure as at Example 11 was used to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 3.

Example 13

[0117] Except for the fact that Dye Derivative b from Manufacturing Example 2 was used instead of Dye Derivative a from Manufacturing Example 1, the same procedure as at Example 11 was used to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 3.

Example 14

[0118] Except for the fact that surface-active-agent-type dispersants in the form of 9 parts by weight of Demol SN-B and 2 parts by weight of NIKKOL BPS-30 were used instead of 15 parts by weight of resin-type dispersant in the form of DISPERBYK-190, and 73 parts by weight of deionized water was used instead of 61.5 parts by weight thereof, the same procedure as at Example 13 was used to obtain a dye dispersion. The composition of the dye dispersion obtained was as indicated at TABLE 3.

Evaluation 1

[0119] Evaluation of the dye dispersions at the Examples and Comparative Example was carried out as follows. Results of evaluation were as shown in TABLES 2 and 3.

Dispersion Stability Testing

[0120] As for dispersion stability, the tendency for particles within the dye dispersion to flocculate during storage was evaluated in accelerated fashion by using the increasing rate in particle diameter as an indicator.

[0121] 10 g of each dye dispersion was collected and placed within a sealed container, and this was allowed to stand for 1 week at 60 C. After cooling this to room temperature, a dynamic light-scattering photometer (ELS-8000 manufactured by Otsuka Electronics Co., Ltd.) was used to measure the average particle diameter (A) of particles within the dye dispersion. Note that stability was evaluated based on the increasing rate relative to the average particle diameter (B) that was measured in the same fashion before this was allowed to stand at 60 C. Increasing rate (%) was calculated using the following formula.

Increasing rate (%)=(AB)/B100

[0122] Evaluative criteria were as follows. [0123] GOOD=Increasing rate of average particle diameter was less than 10% [0124] FAIR=Increasing rate of average particle diameter was greater than or equal to 10% but less than 20% [0125] BAD=Increasing rate of average particle diameter was greater than or equal to 20%

Precipitation Characteristics Testing

[0126] Precipitation characteristics testing was such that the tendency for particles within the dye dispersion to flocculate to the point where precipitation occurred during storage was evaluated in accelerated fashion.

[0127] 100 g of each dye dispersion was collected and placed within a centrifuge tube, and a centrifugal separator (H-201FR manufactured by Kokusan Co., Ltd.) was used to carry out centrifugal separation for 30 minutes at 5000 rpm. Prior to carrying out the centrifugal separation, a 1 g sample of each dye dispersion was collected in advance and placed within an aluminum cup, the weight of the residue that remained after heating this for 2 hours at 130 C. was measured, and the fractional solids content (C %) prior to carrying out the centrifugal separation per 1 g of sample was calculated. Moreover, following the centrifugal separation, 1 g of liquid supernatant was collected from each centrifuge tube and placed within an aluminum cup, and a similar procedure was employed to calculate the fractional solids content (D %) per 1 g of the liquid supernatant. Precipitation characteristics were evaluated based on the difference between the values calculated for C and D as the precipitation ratio of the solid content. The precipitation ratio (%) was calculated using the following formula.

Precipitation ratio (%)=CD

[0128] Evaluative criteria were as follows. [0129] GOOD=Precipitation ratio of solid content was less than 1% [0130] FAIR=Precipitation ratio of solid content was greater than or equal to 1% but less than 2% [0131] BAD=Precipitation ratio of solid content was greater than or equal to 2%

Evaluation 2

[0132] The dye dispersions at the Examples and Comparative Example were used to prepare aqueous ink, and evaluation of that ink was carried out as follows. Results of evaluation were as shown in TABLES 2 and 3.

Ink Stability Testing

[0133] 1 g of each dye dispersion, 0.1 g of surfactant (DISPERBYK-348 manufactured by BYK-Chemie), 1 g of glycerine, 1 g of propylene glycol, and 9 g of deionized water were mixed to prepare aqueous ink. For each aqueous ink obtained, stability of the aqueous ink was evaluated by calculating the increasing rate in average particle diameter in the same manner as at Dispersion Stability Testing.

[0134] Evaluative criteria were as follows. [0135] GOOD=Increasing rate of average particle diameter was less than 10% [0136] FAIR=Increasing rate of average particle diameter was greater than or equal to 10% but less than 100% [0137] BAD=Increasing rate of average particle diameter was greater than or equal to 100%

TABLE-US-00002 TABLE 2 Comparative Example Example 1 2 3 4 5 6 1 Water- D.R.60.sup.1) 15 15 15 15 15 15 15 insoluble D.Y.54.sup.2) dye D.B.359.sup.3) Derivative Manufacturing Example 1 1 1 1 Manufacturing Example 2 1 1 1 Dispersant DISPER 22.5 22.5 22.5 BYK-190 EFKA PX4701 9 9 Demol SN-B 9 9 NIKKOL BPS-30 2 2 Water 61.5 75 73 61.5 75 73 62.5 Dispersion stability testing GOOD FAIR FAIR GOOD GOOD GOOD BAD Precipitation characteristics testing FAIR FAIR GOOD GOOD GOOD GOOD BAD Ink stability testing FAIR GOOD FAIR GOOD GOOD GOOD BAD .sup.1)C.I. Disperse Red 60 .sup.2)C.I. Disperse Yellow 54 .sup.3)C.I. Disperse Blue 359

TABLE-US-00003 TABLE 3 Example 7 8 9 10 11 12 13 14 Water- D.R.60.sup.1) insoluble D.Y.54.sup.2) 15 15 15 15 dye D.B.359.sup.3) 15 15 15 15 Derivative Manufacturing Example 1 1 1 1 1 Manufacturing Example 2 1 1 1 1 Dispersant DISPER 22.5 22.5 22.5 22.5 BYK-190 EFKA PX4701 Demol SN-B 9 9 9 9 NIKKOL BPS-30 2 2 2 2 Water 61.5 73 61.5 73 61.5 73 61.5 73 Dispersion stability testing GOOD FAIR GOOD GOOD GOOD FAIR GOOD GOOD Precipitation characteristics testing FAIR FAIR FAIR FAIR GOOD FAIR GOOD GOOD Ink stability testing GOOD GOOD GOOD GOOD GOOD GOOD GOOD GOOD .sup.1)C.I. Disperse Red 60 .sup.2)C.I. Disperse Yellow 54 .sup.3)C.I. Disperse Blue 359

[0138] As is clear from TABLES 2 and 3, it can be seen that use of dye derivatives as indicated at Formula (1) permits improvement in stability of aqueous dye dispersions and aqueous inks regardless of the type of dispersant and/or the type of water-insoluble dye employed. It is therefore clear that aqueous inks containing the foregoing dye dispersions may be favorably employed for any of various uses, and will in particular be suitable for any of various types of printing for carrying out inkjet recording.