JP3852500B2 - Recording liquid - Google Patents

Description

【０００８】
（式中、Ｒ¹ は、置換もしくは非置換の炭素数１〜４のアルキル基、Ｒ² 及びＲ³ はそれぞれ独立に、水素原子、置換もしくは非置換の炭素数１〜８のアルキル基（但し、水酸基で置換されたアルキル基を除く）又は置換もしくは非置換のフェニル基を表わし、Ｘは水素原子、炭素数１〜４のアルキル基又は炭素数１〜４のアルコキシ基を表わし、Ｙは置換もしくは非置換の炭素数１〜１２のアルキル基、置換もしくは非置換の炭素数６〜１２のアリール基又は下記Ａ群から選ばれる基を表わし、Ｚは水素原子又は置換基を有していてもよいフェニル基を表わし、ｌ及びｍはそれぞれ独立に０、１又は２を表わし、ｎは、１又は２を表わすが、ｌ及びｍが同時に０を表わすことはない。）
（Ａ群）
【０００９】
【化４】

【００１０】
【発明の実施の形態】
本発明について詳細に説明すると、本発明に係る記録液は、水性媒体中に前記一般式（Ｉ）で表わされる色素を含有していることを特徴とするものである。この色素について更に詳細に説明すると、一般式（Ｉ）中のＲ¹ で表わされるアルキル基の置換基としては、炭素数１〜４のアルコキシ基等が挙げられる。Ｒ² 及びＲ³ におけるアルキル基の置換基としては炭素数１〜４のアルコキシ基、フェニル基等が挙げられ、フェニル基の置換基としては、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基等が挙げられる。Ｙにおけるアルキル基の置換基としては炭素数１〜４のアルコキシ基等が挙げられ、アリール基の置換基としては炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基、カルボキシル基等が挙げられる。
【００１１】
Ｚにおけるフェニル基の置換基としては、カルボン酸基（−ＣＯＯＨ）、スルホン酸基（−ＳＯ₃ Ｈ）、炭素数１〜４のアルキル基及び炭素数１〜４のアルコキシ基などが挙げられる。
本発明において用いられる色素は遊離酸の形でも、また、酸性基の対イオンとして、リチウム、ナトリウムなどのアルカリ金属、アンモニア、ヒドロキシル基を有していてもよい炭素数１〜４のアルキル基が窒素原子に１〜４個結合している１〜３級アミンや第４級アンモニウムなどとの塩の形でも、またこれらの混合であってもよい。また、記録液中にはいくつかの異なる対イオンが併存していてもよい。
本発明において用いられる色素の具体例を示す。
【００１２】
【表１】

【００１３】
【表２】

【００１４】
【表３】

【００１５】
【表４】

【００１６】
本発明で用いる前記一般式（Ｉ）で表わされる色素は、それ自体周知の方法〔例えば、細田豊著「新染料化学」（昭和４８年１２月２１日 技報堂発行）第３９６〜４０９頁参照〕に従って、ジアゾ化、カップリング工程を経て製造する事ができる。
記録液中における前記一般式（Ｉ）で表わされる色素の含有量は、記録液全量に対して０．５〜１０重量％、特に２〜４重量％程度が好ましい。なお、色素は単独で用いても、いくつかを併用してもよい。
【００１７】
本発明の記録液を構成する水性媒体としては、水及び水溶性有機溶剤が挙げられるが両者を含むものが好ましい。水溶性有機溶剤としては、例えばエチレングリコール、プロピレングリコール、ブチレングリコール、ジエチレングリコール、トリエチレングリコール、ポリエチレングリコール（＃２００）、ポリエチレングリコール（＃４００）、グリセリン、Ｎ−メチルピロリドン、Ｎ−エチルピロリドン、１，３−ジメチルイミダゾリジノン、チオジエタノール、ジメチルスルホキシド、エチレングリコールモノアリルエーテル、エチレングリコールモノメチルエーテル、ジエチレングリコールモノメチルエーテル、２−ピロリドン、スルホラン、エチルアルコール、イソプロパノール等を用いるのが好ましい。これ等の水溶性有機溶剤は、通常、記録液の全量に対して５〜３０重量％、好ましくは５〜２０重量％の範囲で使用される。一方、水は記録液の全量に対して通常、６０〜９０重量％、好ましくは、７５〜９０重量％の範囲で使用される。
【００１８】
本発明の記録液は、その全量に対して０．１〜１０重量％、好ましくは０．５〜５重量％の尿素、チオ尿素、ビウレット、セミカルバジドから選ばれる化合物を添加したり、又０．００１〜５．０重量％の界面活性剤を添加することによって、印字後の速乾性及び印字品位をより一層改良することができる。
【００１９】
【実施例】
以下、本発明を実施例について更に詳細に説明するが、本発明のその要旨を超えない限りこれ等の実施例に限定されるものではない。
実施例１
ジエチレングリコール１０重量部、イソプロピルアルコール３重量部、第１表のＮｏ．１の色素３重量部に水を加え、アンモニア水でｐＨを９に調整して全量を１００重量部とした。この組成物を充分に混合して溶解し、孔径１μｍのテフロンフィルターで加圧濾過した後、真空ポンプ及び超音波洗浄機で脱気処理して記録液を調製した。
【００２０】
得られた記録液を使用し、インクジェットプリンター（商品名ＢＪ−１０Ｖ、キャノン社製）を用いて電子写真用紙Ｘｅｒｏｘ ４０２４紙（富士ゼロックス社製）にインクジェット記録を行なう印字試験を行ない、高濃度の青味黒色の印字物を得た。また、下記（ａ）、（ｂ）、（ｃ）及び（ｄ）の方法による評価を行なった結果を示す。
【００２１】
（ａ）記録画像の耐光性：
キセノンフェードメーター（スガ試験機社製）を用い、記録紙に１００時間照射した。照射後の変退色は小さかった。
（ｂ）記録画像の耐水性：
水道水中に記録紙を５秒間浸漬した後の画像の滲みを調べたが、画像の滲みは殆んど認められなかった。
【００２２】
（ｃ）記録液の保存安定性：
記録液をテフロン容器中に密閉し、５℃及び６０℃で１ケ月間保存した後の変化を調べたところ、不溶物の析出は認められなかった。
（ｄ）記録液の再吐出性
上記印字試験後の記録液の充填されたプリンターを、常温、常湿に２ケ月間放置後、再び吐出性試験を行ったところノズルの目詰まりもなく、放置前と同様に安定な吐出特性が得られた。
【００２３】
なお、上記（ａ）〜（ｄ）の各評価の評価基準は下記のとおりである。
（ａ）記録画像の耐光性
○−良好。
△−変退色あるが実用上問題なし。
×−変退色がひどい。
（ｂ）記録画像の耐水性
○−滲みほとんどなし。
△−かすかに滲みあるが実用上問題なし。
×−滲みがひどい。
【００２４】
（ｃ）記録液の保存安定性
○−ゲル化や沈殿物ほとんどなし。
△−かすかにゲル化や沈殿物がみられるが実用上問題なし。
×−ゲル化や沈殿物がひどい。
（ｄ）記録液の再吐出性
○−目詰まりなど無く、安定でかつ良好な吐出性を示した。
△−印字物にかすかにドット抜けがあるが、実用上問題なし。
×−印字物のドット抜けがひどい。
【００２５】
実施例２〜４
実施例１において用いた第１表のＮｏ．１の色素の代わりに、第１表のＮｏ．２、Ｎｏ．３及びＮｏ．４の色素をそれぞれ使用した以外は、実施例１と同じ方法により、記録液を調製し、これを用いて印字を行い、黒色の記録物を得た。更に実施例１と同様に（ａ）〜（ｄ）による諸評価を行ったところ、実施例１と同様に何れも良好な結果を得た。
【００２６】
比較例１〜２
実施例１におけるＮｏ．１の色素の代りに、特開平７−３４０２０号公報に記載されている下記構造式Ｒ−１及びＲ−２の色素を用い、実施例１と同じ方法により記録液を調製し、これを用いて印字を行い、記録物を得た。更に実施例１と同様に（ａ）〜（ｄ）による諸評価を行った結果を第２表に示す。
【００２７】
【化５】

【００２８】
【表５】

【００２９】
実施例５〜１０
実施例１において用いた第１表のＮｏ．１の色素の代わりに、第１表のＮｏ．５〜Ｎｏ．１０の色素を使用した以外は、実施例１と同じ方法により記録液を調製し、印字を行い、この記録物に対して実施例１の（ａ）〜（ｄ）による諸評価を行なった。その結果、実施例１と同様に何れも良好な結果を得た。
【００３０】
【発明の効果】
本発明の記録液は、インクジェット記録用、筆記用具用として用いられ、普通紙に記録した場合、黒色系の記録物を得ることができ、その印字濃度及び耐光性、耐水性が優れている他、記録液としての保存安定性、再吐出性も良好である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording liquid. Specifically, the present invention relates to a black recording liquid suitable for ink jet recording.
[0002]
[Prior art]
A so-called ink jet recording method has been put to practical use in which recording is performed by ejecting droplets of a recording liquid containing a direct dye or a water-soluble dye such as an acid dye from a minute ejection orifice. This recording liquid is widely used for general office work such as PPC (plain paper copier) paper such as electrophotographic paper, fan hold paper (continuous paper such as computer), etc. It requires fast fixing to recording paper and good print quality, that is, the print must have no blur and have a clear outline, and has excellent stability when stored as a recording liquid. It is necessary to be.
[0003]
Therefore, as a dye for recording liquid, it has sufficient solubility in the solvent of the recording liquid, is stable even when stored as a recording liquid for a long time, and has a high density of printed images. It is required to have excellent water resistance and light resistance, but it is difficult to satisfy these many requirements at the same time.
For this reason, various methods (for example, Japanese Patent Laid-Open Nos. 55-140467, 55-152747, 57-207660, 58-147470, 62-190269, JP 62-190271, JP 62-190272, JP 62-250082, JP 62-246975, JP 62-257971, JP 62-288659, JP 63- No. 8463, No. 63-22867, No. 63-22874, No. 63-30567, No. 63-33484, No. 63-63964, No. 63-105079 JP-A-64-31877, JP-A-1-93389, JP-A-1-210464, JP-A-2-140270, JP-A-3-167270, JP-A-3-2000088. Although etc. See the publication) have been proposed, it does not reach the development of easy dye prepared with satisfying sufficiently the requirements of performance market.
[0004]
Japanese Patent Application Laid-Open No. 7-34020 and European Patent Publication No. 757087 disclose disazo dyes having a carboxyl group having a structure similar to that of the present invention as a substituent. It is made into ink by substituting with a salt. However, dyes having these carboxyl groups and substituted with volatile salts (ammonia, amine, etc.) are excellent in the water resistance of printed matter, but as inks dissolved in water and organic solvents. Dissolving stability is poor, and such inks gradually volatilize ammonia or amine at the tip of the discharge nozzle, etc., resulting in a decrease in dye solubility and precipitation at the tip of the nozzle. Thus, the quality of the printed image may be inferior. In addition, when a hydroxyl group is introduced as a substituent of the phenyl group at the end of the dye molecule, the ejection stability is not improved, and the water resistance tends to decrease because the group has high hydrophilicity.
As a result, sufficient performance has not been obtained.
[0005]
[Problems to be solved by the invention]
The present invention has good print quality even when recorded on plain paper, such as for inkjet recording and writing utensils, etc., and has a high recorded image density, excellent water resistance and light resistance, and is stored for a long time. It is an object of the present invention to provide a recording liquid having good stability in the case of the above. In particular, it is suitably used as a black recording liquid.
[0006]
[Means for Solving the Problems]
The present invention resides in a recording liquid characterized in that the free acid form contains a dye represented by the general formula (I) and an aqueous medium.
[0007]
[Chemical 3]

[0008]
Wherein R ¹ is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ² and R ³ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms (provided that Represents a substituted or unsubstituted phenyl group, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and Y represents a substituted group. Alternatively, it represents an unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or a group selected from the following group A, and Z may have a hydrogen atom or a substituent. Represents a good phenyl group, l and m each independently represent 0, 1 or 2; n represents 1 or 2, but l and m do not represent 0 at the same time.
(Group A)
[0009]
[Formula 4]

[0010]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail. The recording liquid according to the present invention is characterized in that the dye represented by the general formula (I) is contained in an aqueous medium. The dye will be described in more detail. Examples of the substituent of the alkyl group represented by R ¹ in the general formula (I) include an alkoxy group having 1 to 4 carbon atoms. Examples of the substituent of the alkyl group in R ² and R ³ include an alkoxy group having 1 to 4 carbon atoms and a phenyl group. Examples of the substituent of the phenyl group include an alkyl group having 1 to 4 carbon atoms and 1 to 1 carbon atom. 4 alkoxy groups and the like. Examples of the substituent of the alkyl group in Y include an alkoxy group having 1 to 4 carbon atoms, and examples of the substituent for the aryl group include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a carboxyl group, and the like. Is mentioned.
[0011]
Examples of the substituent of the phenyl group in Z include a carboxylic acid group (—COOH), a sulfonic acid group (—SO ₃ H), an alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms.
The dye used in the present invention may be in the form of a free acid, or an alkali metal such as lithium or sodium, ammonia, or an alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group as a counter ion of the acidic group. It may be in the form of a salt with a primary to tertiary amine or quaternary ammonium bonded to 1 to 4 nitrogen atoms, or a mixture thereof. Also, several different counter ions may coexist in the recording liquid.
The specific example of the pigment | dye used in this invention is shown.
[0012]
[Table 1]

[0013]
[Table 2]

[0014]
[Table 3]

[0015]
[Table 4]

[0016]
The coloring matter represented by the general formula (I) used in the present invention is a method known per se [for example, see Hosoda Yutaka "New Dye Chemistry" (published December 21, 1973, Gihodo, pages 396-409)] Thus, it can be produced through a diazotization and coupling process.
The content of the dye represented by formula (I) in the recording liquid is preferably about 0.5 to 10% by weight, particularly about 2 to 4% by weight, based on the total amount of the recording liquid. In addition, a pigment | dye may be used independently or several may be used together.
[0017]
Examples of the aqueous medium constituting the recording liquid of the present invention include water and water-soluble organic solvents, but those containing both are preferable. Examples of the water-soluble organic solvent include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (# 200), polyethylene glycol (# 400), glycerin, N-methylpyrrolidone, N-ethylpyrrolidone, 1 , 3-dimethylimidazolidinone, thiodiethanol, dimethyl sulfoxide, ethylene glycol monoallyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, 2-pyrrolidone, sulfolane, ethyl alcohol, isopropanol and the like are preferably used. These water-soluble organic solvents are usually used in the range of 5 to 30% by weight, preferably 5 to 20% by weight, based on the total amount of the recording liquid. On the other hand, water is usually used in the range of 60 to 90% by weight, preferably 75 to 90% by weight, based on the total amount of the recording liquid.
[0018]
In the recording liquid of the present invention, 0.1 to 10% by weight, preferably 0.5 to 5% by weight, of the compound selected from urea, thiourea, biuret and semicarbazide is added to the total amount of the recording liquid. By adding 001 to 5.0% by weight of a surfactant, quick drying after printing and printing quality can be further improved.
[0019]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, unless it exceeds the summary of this invention, it is not limited to these Examples.
Example 1
10 parts by weight of diethylene glycol, 3 parts by weight of isopropyl alcohol, No. 1 in Table 1. Water was added to 3 parts by weight of 1 dye, and the pH was adjusted to 9 with aqueous ammonia to make the total amount 100 parts by weight. This composition was sufficiently mixed and dissolved, pressure filtered through a Teflon filter having a pore size of 1 μm, and degassed with a vacuum pump and an ultrasonic cleaner to prepare a recording liquid.
[0020]
Using the obtained recording liquid, an ink jet printer (trade name BJ-10V, manufactured by Canon Inc.) was used to perform a printing test for performing inkjet recording on electrophotographic paper Xerox 4024 paper (Fuji Xerox Co., Ltd.). A bluish black print was obtained. Moreover, the result of having evaluated by the method of following (a), (b), (c) and (d) is shown.
[0021]
(A) Light resistance of recorded image:
Using a xenon fade meter (manufactured by Suga Test Instruments Co., Ltd.), the recording paper was irradiated for 100 hours. The fading color after irradiation was small.
(B) Water resistance of recorded image:
The bleeding of the image after immersing the recording paper in tap water for 5 seconds was examined, but almost no bleeding of the image was observed.
[0022]
(C) Storage stability of recording liquid:
When the recording liquid was sealed in a Teflon container and stored at 5 ° C. and 60 ° C. for 1 month, changes in the recording liquid were examined. No precipitation of insoluble matter was observed.
(D) Recording liquid re-ejectability The printer filled with the recording liquid after the printing test was left at room temperature and normal humidity for 2 months, and then the discharging property test was performed again. As before, stable ejection characteristics were obtained.
[0023]
In addition, the evaluation criteria of each evaluation of said (a)-(d) are as follows.
(A) Light resistance of the recorded image ○ -good.
Δ: Discoloration but no problem in practical use.
×-Discoloration is terrible.
(B) Water resistance of the recorded image.
Δ: Slightly bleeding but no problem in practical use.
X-Breaking is severe.
[0024]
(C) Storage stability of the recording liquid ○ —No gelation or precipitation.
Δ—Slight gelation or precipitation is observed, but there is no practical problem.
X-Severe gelation and precipitation.
(D) Re-ejectability of recording liquid ○ —Stable and good ejectability was exhibited without clogging.
Δ-The printed material has faint missing dots, but there is no practical problem.
×-The dot missing on the printed matter is severe.
[0025]
Examples 2-4
No. 1 in Table 1 used in Example 1. No. 1 in Table 1 in place of the dye of No. 1. 2, no. 3 and no. A recording liquid was prepared in the same manner as in Example 1 except that each of the dyes 4 was used, and printing was performed using this to obtain a black recorded matter. Furthermore, when various evaluations by (a) to (d) were performed in the same manner as in Example 1, good results were obtained in the same manner as in Example 1.
[0026]
Comparative Examples 1-2
No. 1 in Example 1. A recording liquid was prepared by the same method as in Example 1 using the dyes of the following structural formulas R-1 and R-2 described in JP-A-7-34020 instead of the dye 1 and using this. Printing was performed to obtain a recorded matter. Further, the results of various evaluations according to (a) to (d) as in Example 1 are shown in Table 2.
[0027]
[Chemical formula 5]

[0028]
[Table 5]

[0029]
Examples 5-10
No. 1 in Table 1 used in Example 1. No. 1 in Table 1 in place of the dye of No. 1. 5-No. A recording solution was prepared and printed by the same method as in Example 1 except that 10 dyes were used, and various evaluations according to (a) to (d) of Example 1 were performed on the recorded matter. As a result, similar to Example 1, good results were obtained.
[0030]
【The invention's effect】
The recording liquid of the present invention is used for inkjet recording and writing instruments, and when recorded on plain paper, a black-based recorded matter can be obtained, and its print density, light resistance, and water resistance are excellent. Also, the storage stability as a recording liquid and re-ejection properties are good.

Claims (2)

A recording liquid comprising a dye having a free acid form represented by formula (I) and an aqueous medium.

Wherein R ¹ is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ² and R ³ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms (provided that Represents a substituted or unsubstituted phenyl group, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and Y represents a substituted group. Alternatively, it represents an unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or a group selected from the following group A, and Z may have a hydrogen atom or a substituent. Represents a good phenyl group, l and m each independently represent 0, 1 or 2; n represents 1 or 2, but l and m do not represent 0 at the same time.
(Group A)

A disazo dye for recording liquid, wherein the free acid type is represented by formula (I).

(Wherein R ¹ Is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ² And R ^Three Each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms (excluding an alkyl group substituted with a hydroxyl group) or a substituted or unsubstituted phenyl group, X is a hydrogen atom, Represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and Y represents a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or Represents a group selected from the following group A, Z represents a hydrogen atom or an optionally substituted phenyl group, l and m each independently represent 0, 1 or 2, and n represents 1 or 2 , But l and m do not represent 0 at the same time. )
(Group A)