WO2002072717A1

WO2002072717A1 - Ink jet recording ink composition

Info

Publication number: WO2002072717A1
Application number: PCT/JP2002/002061
Authority: WO
Inventors: Hiroyuki Ueki; Hiroyuki Endoh; Yasuharu Onishi
Original assignee: Fuji Xerox Co., Ltd.
Priority date: 2001-03-06
Filing date: 2002-03-06
Publication date: 2002-09-19
Also published as: JP2002265825A; JP4867072B2

Abstract

An ink jet recording ink composition characterized in that ultrasonic transmission amount, measured by using a paper medium that requires a maximum ultrasonic transmission time of up to 1 sec until a maximum ultrasonic transmission amount is reached when water is absorbed, is represented by at least 90% in 1 sec. This ink jet recording ink composition can increases an ink fixing speed with respect to general plain paper having fibers thereof exposed to its recording surface and having been subjected to sizing, and can prevent a strike-through.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an ink jet recording ink composition.

The present invention relates to a recording ink composition for use in an ink jet printer, and has a high fixability to a paper generally used in offices and homes, such as copy paper and report paper, and has high print quality without strikethrough. The present invention relates to an ink jet recording ink composition which enables excellent recording. Field Conventional technology

Ink jet printers form ink droplets by various ejection methods, and perform recording by attaching some or all of the ink droplets to a recording medium such as paper or a plastic film.

In recent years, inkjet printers have become widespread as digital signal output devices such as computers because of their advantages such as low noise, low running cost, and ease of color printing, and high-speed printing and double-sided printing over electrophotographic printers are desirable. It became as to be.

As the ink used in such an ink jet recording system, there is one in which various dyes and pigments are dissolved or dispersed in water or a liquid medium composed of water and a water-soluble organic solvent.

In general, such an ink is required to be free from bleeding, fast in fixing speed, and not to block nozzles of a printer head even after a pause.

In order to meet these performances, both ink and printers have been studied, and some of the above requirements have been significantly effective.

For example, Japanese Patent Application Laid-Open No. 2000-178489 discloses that at least an aqueous ink comprising water, a colorant, an organic solvent and a surfactant contains a surfactant represented by the chemical formula (1). Aqueous ink characterized by containing at least one or more types You.

CH ₃ CH ₃ CH¾ CH ₃

CH ₃ ~ CH-CH ₂ -CH _Z -CC≡CC-CH ₂ ~ CH ₂ -GH ₂ -CH ₂

Japanese Patent Application Laid-Open No. 2000-290549 discloses that at least one of the acetylene glycol compounds represented by the general formula (2) and the alkylene oxide represented by the general formula (3) A water-based ink containing at least one polymer, a colorant, and water has been proposed.

(Wherein, R i and R ₃ are a branched alkyl group having 4 to 17 carbon atoms, R ₂ and R ₄ are an alkyl group having 1 to 10 carbon atoms, and m and n are 0 or Is a positive integer)

(3)

(In the formula, ml and n 1 are 0 or a positive integer, R is H, an alkyl group having 1 to 10 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms.)

Japanese Patent Application Laid-Open No. 2000-239583 discloses that a recording liquid in an ink jet recording in which a recording liquid is caused to fly from an orifice formed on a metal plate, and the recording liquid is dissolved in water, a coloring agent, a penetrant, and a wetting agent. An ink set composed of yellow, magenta, cyan, and black inks, and a yellow ink containing at least Projet Fast It contains Iero II 2 (manufactured by Zeneki) and CI Direct Yellow 142 as colorants, magenta ink contains at least CI Acid Red 52 as a colorant, and cyan ink contains at least Projet Fast Cyan. 2 (manufactured by Zeneca) as a colorant, and the black ink contains at least CI Direct Black 168 as a colorant. A color set for ink-jet recording characterized by having a color set is proposed.

JP-A-2000-239589 is an ink containing a first pigment and a second pigment as a colorant in a dispersed state in an aqueous medium, wherein the first pigment is directly or directly coated with at least one anionic group. A self-dispersing pigment or at least one cationic group bound to the surface of the first pigment via another group directly or via another group to the surface of the first pigment; A second pigment is a pigment that can be dispersed in an aqueous medium by a polymer dispersant, and the ink is further bound to the surface of the first pigment. An ink characterized by including at least one of a polymer dispersant having the same polarity as the group and a nonionic polymer dispersant has been proposed. Japanese Patent Application Laid-Open No. 2000-318030 discloses an ink jet recording method in which an ink containing a coloring material, a water-soluble organic solvent, and water is attached to a recording medium containing a polymer substance. In the method, there is proposed an ink jet recording method, wherein the polymer substance causes the coloring material to aggregate.

However, the inks proposed in these publications do not fully satisfy all the above-mentioned characteristics.

At present, in view of the spread of plain paper use in offices, it is desirable to reduce the amount of print paper used in consideration of environmental issues, and as a result, the demand for double-sided printing is increasing. In order to satisfy this demand, it is necessary to control the penetration of the ink into the paper medium to suppress the strike-through of the ink.

One solution to this problem is to use solid ink at room temperature. Since this method heats the ink and records it in a liquid state, it has some effect on strike-through, but when designing a printer, it is necessary to use a device or a printer head to supply ink while dissolving the ink. Since it is necessary to provide a heating device in the printer, there is a problem that the size of the printer is increased and the cost is increased.

There is also a method of increasing the surface tension of the liquid ink at room temperature to delay the penetration of the ink.However, when performing high-speed printing, the drying time of the ink becomes slow, which is not suitable for high-speed printing. .

In addition, there is a method of reducing the amount of ink droplets attached to the recording medium, but it is not practical because control of print density on the recording surface and complicated processing for forming ink droplets are required.

In view of the problems with the conventional ink composition as described above, the present invention relates to a general plain paper that has fibers exposed on a recording surface, such as copy paper and report paper, and is further subjected to sizing processing. An object of the present invention is to provide an ink composition having a high fixing speed and no strikethrough.

In addition, the Pristo method is known as a method of measuring the absorption characteristics of a liquid into a paper medium, but in the Bristow method, the liquid penetrates into the space formed by the paper fibers and the paper fibers themselves. Indistinguishable from liquid absorption could not be distinguished. Furthermore, it was difficult to prepare measurement environment conditions such as temperature and humidity. In view of the problems in the Bristow method, the present inventor has determined that the penetration of liquid into the space formed by paper fibers, which was impossible with the conventional Bristow method, is equivalent to the absorption of liquid into the paper fibers themselves. An object of the present invention is to provide a method for evaluating the permeability of an ink composition, which can be separately measured. Disclosure of the invention

In order to achieve the above object, the present invention measures using a paper medium in which the time required for the amount of ultrasonic transmission when water is absorbed to be maximum (ultrasonic maximum transmission time) is 1 second or more. Provided is an ink composition for ink jet recording, wherein the transmitted ultrasonic wave amount is 90% or less in one second.

The ultrasonic transmission is measured using a dynamic permeability tester that measures the absorption of liquid into paper media using ultrasonic waves. Specifically, for example, 0-1 [(DynamicPennetrationTiestErr) manufactured by £ 11100 can be used. As the paper medium, use plain paper that has a maximum ultrasonic transmission time of 1 second or more when water is absorbed. As such a paper medium, for example, 024 paper manufactured by XEROX can be used.

It is preferable that the rate of decrease in ultrasonic transmission amount per unit time (maximum decrease inclination angle) is 50% or more. '

Further, the frequency of the ultrasonic wave used for measuring the ultrasonic transmission amount is preferably 2 MHz.

Long wavelength ultrasonic waves are convenient for examining differences due to the large structure of the paper medium, but when examining differences due to minute structures, it is preferable to use shorter ultrasonic waves.

Further, the ink composition for ink jet recording according to the present invention may contain an acetylenic alcohol-based surfactant or an amine-based surfactant.

In this case, the content of these surfactants is preferably in the range of 0.01 to 5% by weight based on the total weight of the ink composition for ink jet recording, and in the range of 1 to 1% by weight. Is more preferred.

In the ink jet recording ink composition according to the present invention, as the main solvent, Each time water or a water-soluble organic solvent is used.

In this case, the amount of water or the water-soluble organic solvent is preferably in the range of 1 to 40% by weight based on the total weight of the ink composition for ink jet recording.

Further, the ink composition for ink jet recording according to the present invention can contain a dye as a coloring material.

It is preferable to use a disperse dye as the dye.

The content of the dye is preferably in the range of 0.1 to 10% by weight, more preferably 1 to 5% by weight, based on the total weight of the ink jet recording ink composition.

Further, the ink composition for ink jet recording according to the present invention can contain a pigment as a coloring material.

As the pigment, for example, a force pump rack is preferably used.

The content of the pigment is preferably in the range of 3 to 15% by weight, more preferably 5 to 10% by weight, based on the total weight of the ink jet recording ink composition. The ink jet recording ink composition according to the present invention preferably has a surface tension of 30 to 40 dynes at 20 to 25 degrees Celsius. As described above, it was impossible with the conventional Pristo method to measure the permeation of liquid by capillary action into the space formed by paper fibers separately from the absorption of liquid into the paper fibers themselves. Therefore, as a result of studying a method that enables such measurement, the present inventor has found that such a measurement is possible according to a dynamic permeability tester using ultrasonic waves. Was.

For this reason, the present invention measures the change in the ultrasonic transmission intensity of the paper medium to which the ink composition for ink jet recording has been applied using a dynamic absorption tester using ultrasonic waves. A method for evaluating the permeability of the ink composition for ink jet recording is provided.

The preferred frequency of the ultrasound used is 2 MHz. Detailed Description of the Preferred Embodiment

The present invention relates to a method for immersing ink in a recording material in which fibers are exposed on the recording surface. This is based on the knowledge obtained as a result of examining the permeability behavior in relation to the properties of the ink composition.

It is considered that the ink is absorbed into the paper medium by the following three processes.

(1) Air between paper fibers is replaced with ink liquid by capillary action.

(2) the ink liquid is absorbed by the paper fibers,

(3) When the paper fiber swells due to the absorption of the ink liquid, the lumen (small cavities) in the fiber structure opens, and the micro air in it is replaced by the ink liquid.

In paper with sizing agent and starch internally added, the paper fiber itself shows hydrophobicity, so the ink liquid absorption in the paper in the initial stage is only due to the capillary phenomenon, and the paper fiber itself does not absorb liquid. .

According to the method for measuring liquid absorption into a paper medium by a dynamic permeability tester using ultrasonic waves according to the present invention, the penetration of the liquid into the space of the paper fiber due to the capillary phenomenon is separated from the absorption of the liquid into the paper fiber itself. It can be measured separately.

This is based on the fact that the measuring method according to the present invention utilizes the property of ultrasonic waves that the harder the material, the better the transmission.

Therefore, since the ink liquid has a better ultrasonic wave transmission property than the air, when the air between the paper fibers is replaced with the ink liquid, the transmission amount of the ultrasonic wave increases, and subsequently, the ink liquid is transmitted to the paper fibers. As the absorption progresses, the stiffness decreases, the paper medium becomes more flexible, and the ultrasonic transmission decreases.

The ultrasonic transmission amount is measured using a dynamic permeability tester provided with an ultrasonic transmitting unit and an ultrasonic receiving unit. One example of such a dynamic permeability tester is DPM (Dynamic Penetration at Testell) manufactured by Emco.

The measurement by the DPM manufactured by Emco is performed as follows.

First, a paper medium as a sample is fixed to the sample holder, and the paper medium is immersed in the liquid together with the sample holder.

The ultrasonic waves emitted from the ultrasonic transmission unit pass through the liquid, pass through the paper medium fixed to the sample hologue, and reach the ultrasonic reception unit located on the opposite side of the ultrasonic transmission unit .

At the ultrasonic receiver, the intensity change of the ultrasonic waves emitted from the ultrasonic transmitter is measured Is done. This ultrasonic intensity changes depending on the degree of liquid penetration into the paper medium.

The ultrasonic transmission amount is 100% when the area between the ultrasonic transmitting unit and the ultrasonic receiving unit of the dynamic permeability tester is filled with only liquid (ink). Is expressed as a percentage (%).

The ultrasonic transmission amount increases as the air between the paper fibers is replaced with a liquid. In the case of DPM manufactured by Emco, when the air remaining in the space of the paper fiber is completely replaced with the ink liquid, the ultrasonic transmission amount is 99.9%.

In the present invention, the reduction rate (%) of the ultrasonic transmission amount per unit time at which the reduction rate of the ultrasonic transmission amount becomes the maximum is referred to as the maximum decreasing inclination angle of the ultrasonic transmission amount. The time required from the time when the paper medium is immersed in the liquid to the time when the ultrasonic transmission amount becomes maximum is referred to as the maximum ultrasonic transmission time.

The ink liquid that quickly penetrates the paper fibers due to the capillary phenomenon is suppressed from reaching the back surface of the paper medium, that is, the surface opposite to the recording surface, so that strikethrough can be reduced. is there.

Further, an ink liquid having a high absorption rate for paper fibers can increase the fixing rate of the ink composition to the recording surface of a paper medium.

The term “fixing of the ink composition” as used herein refers to a state in which the hand is not stained even when the recording surface of the paper medium is touched with the hand, and specifically, the same as the sample at 3 seconds after the solid printing. This refers to a state in which a paper medium is rubbed on the printing surface and no transfer occurs.

Specifically, the inventor of the present invention has proposed that the maximum transmission time of ultrasonic waves at 2 MHz when water is absorbed is 1 second or more (for example, XEROX's paper sheet of 204). In contrast, an ink with a characteristic that the transmission amount of 2 MHz ultrasonic wave is 90% or less in one second and the maximum decreasing inclination angle of the ultrasonic transmission amount is 50% or more It has been found that the composition is able to achieve the stated objectives.

As the surfactant that can be contained in the ink composition for inkjet recording according to the present invention, any surfactant can be used as long as it is a compound having a high affinity for water. An acetylene glycol-based surfactant or an amine-based surfactant can be suitably used.

The content of the surfactant depends on the surface tension set for the ink composition. It is in the range of 0.01 to 5% by weight, preferably 0.1 to 1% by weight, based on the total weight.

When the content of the surfactant is less than 0.01% by weight, the surface tension of the ink composition is high, and the fixing time to the recording medium is delayed. On the other hand, when the content exceeds 5% by weight, the surface tension of the ink composition becomes low, and the ejection stability deteriorates.

Another component that can be included in the ink composition for inkjet recording according to the present invention is a coloring material. As the coloring material, for example, direct dyes, acid dyes, basic dyes, reactive dyes and other water-soluble dyes can be used.

Specifically, C.I.Direct Yellow 1 86, 132, 144, C.I.Direct Red 2 27, C.I.Direct Bull 1 199, C.I.Direct Direct dyes such as black 154, acid dyes such as C.I. Acid Yellow 23, C.I. Acid Red 52, and C.I. Acid Blue 9 can be used. , Are used in combination.

The preferred content of these coloring materials is determined depending on the type of the liquid medium component, the characteristics required for the ink, and various other parameters. In general, the content is 0.1 to the total weight of the ink. To 10% by weight, preferably 1 to 5% by weight.

Other colorants that can be included in the ink jet recording ink composition of the present invention include pigments. .

As the pigment, either an inorganic pigment or an organic pigment can be used.

As inorganic pigments, titanium oxide, iron oxide, contact black, furnace black or thermal black can be used.

As the organic pigment, azo pigments, polycyclic pigments such as phthalocyanine pigments and anthraquinone pigments, nitro pigments, aniline black, nitroso pigments and the like can be used.

The pigment is preferably dispersed in the recording ink using a dispersant. As the dispersant, a commonly used polymer dispersant or surfactant can be used. It is also possible to use self-dispersible carbon black whose surface has been oxidized as a coloring material.

Alternatively, it is also possible to use a disperse dye instead of the pigment.

The preferred content of these coloring materials is determined depending on the type of the liquid medium component, the characteristics required for the ink, and various other parameters. In general, the content is preferably 3 to the total weight of the ink. To 15% by weight, preferably 5 to 10% by weight. As an aqueous liquid medium for dissolving these coloring materials, generally, any of those used in ink for ink jet recording can be used.

In particular, water and a water-soluble organic solvent are preferred. Examples of the water-soluble organic solvent include glycols such as ethylene glycol, diethylene glycol, glycerin, and propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monoethyl ether. Dalicol ethers such as butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, 2-pyrrolidone, It can be appropriately selected from N-methyl-2-pyrrolidone and the like. The amount of water or water-soluble organic solvent used as the main solvent is preferably 1 to 40% by weight based on the total weight of the ink.

Further, it is possible to add various dispersing agents, viscosity adjusting agents, pH adjusting agents, force-proofing agents and the like.

Next, examples and comparative examples of the ink composition for inkjet recording according to the present invention will be described.

In the present embodiment, the amount of the surfactant added is adjusted so that the surface tension of the following mixture is 33 dyne / cm. The surface tension was measured using Kyowa Interface Science CBVPZ.

(Example 1)

C.I.Director Yellow 1 3 2 3.5 weight%

Glycerin 15% by weight Diethylene glycol monobutyl ether

Acetylene glycol surfactant

Orfin E 1010 (manufactured by Nissin Chemical Co., Ltd.)

Water The mixture containing the above components was stirred and mixed at room temperature for 2 hours, and filtered through a filter having a pore size of 0.45 / m to obtain an ink composition according to Example 1.

Next, the ink composition of Example 1 and 4024 paper made by XEROX Co., Ltd. were set in a dynamic permeability tester DPM manufactured by Eco, Inc., and the permeability of the ink composition was adjusted to 2 MHz by ultrasonic waves at 20 ° C. It evaluated on condition of.

Further, the printing characteristics of this ink were evaluated using an ink jet printer MJ-520C manufactured by Seiko Epson Corporation.

Table 1 shows the evaluation results.

(Example 2)

C.I.Direct Yellow 132 3.5% by weight

Glycerin 3% by weight

Amine surfactant

Nissan Nai Mean L-207 (manufactured by NOF Corporation) 1% by weight

Water A mixture having the above components was prepared in the same manner as the ink composition of Example 1, and evaluated in the same manner as the ink composition of Example 1.

Table 1 shows the evaluation results.

(Example 3)

CAB— 0— J ET 300 7% by weight

Glycerin 15% by weight

Diethylene glycol monobutyl ether Acetylene glycol surfactant

Orufin E 1 0 1 0 (Nissin Chemical Co., Ltd.)

Table 1 shows the evaluation results.

(Comparative Example 1)

C.I.direct yellow 1 3 23.5 weight%

Glycerin

Diethylene glycol monobutyl ether

Acetylene glycol surfactant

Dynor 6 04 (made by Air Products) 0.0 2% by weight

Water balance A mixture having the above components was prepared in the same manner as the ink composition of Example 1, and evaluated in the same manner as the ink composition of Example 1.

Table 1 shows the evaluation results.

(Comparative Example 2)

C.I.Direct yellow 1 3 23.5 weight% glycerin 15 weight% diethylene glycol monobutyl ether

Silicone surfactant

KM-75 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.2% by weight water A mixture having the above components was prepared in the same manner as the ink composition of Example 1, and Was evaluated in the same manner as the ink composition of

Table 1 shows the evaluation results.

(table 1)

The evaluation of fixability in Table 1 was performed as follows.

After printing solid on XEROX 4024 paper and rubbing the printed area 3 seconds later with another XEROX 4024 paper, fix it by determining whether the print is transferred to the other XEROX 4024 paper. The sex was evaluated.

In Table 1, “◎” indicates that there was no transfer in the normal mode, “〇” indicates that the transfer was slight in the normal mode, but there was no transfer in the high-speed mode, and “X” indicates that there was no transfer in the normal mode. This indicates that transfer has occurred in any of the high-speed modes.

The evaluation of strikethrough in Table 1 was performed as follows.

Two hours after performing solid printing on 4024 paper manufactured by XEROX, the presence or absence of ink penetration to the back surface of the solid printing part was evaluated to evaluate strike-through.

In Table 1, “◎” indicates that there was no ink leakage to the back side, “〇” indicates that some ink leakage was recognized partially, and “x” indicates that ink was completely removed on the entire back side of the solid print area. Indicates that is recognized.

As can be seen from Table 1, the ink compositions according to Examples 1, 2 and 3 in which the amount of ultrasonic transmission after 1 second is 90% or less and the maximum decreasing inclination angle (%) is 50% or more. Has no transcription and no strikethrough.

Although the above experiment was performed under the conditions of 20 degrees Celsius and surface tension of 33 dyncm, according to the experiment conducted at the same time, the temperature was within the range of 20 degrees Celsius to 25 degrees Celsius. Also obtained similar results. Similar experiments were performed with the surface tension of the mixture varied in the range of 30 dyne / cm to 40 dyne / cm. In this case, similar results were obtained. Industrial applicability

As described above, according to the ink composition for inkjet recording according to the present invention, the fiber is exposed on the recording surface and the fixing speed of the ink is higher than that of ordinary sizing-treated plain paper. It is possible to prevent strikethrough.

In addition, by using a dynamic absorption tester that uses ultrasonic waves, it is possible to understand the behavior of ink liquid in paper media, and thus to appropriately evaluate the penetration characteristics of ink liquid into paper media. Becomes possible.

Claims

The scope of the claims

1. The time required for the maximum amount of ultrasonic transmission when water is absorbed (maximum ultrasonic transmission time) is 1 second or more. An ink composition for ink jet recording, characterized in that the content is 90% or less.

2. The ink composition for ink jet recording according to claim 1, wherein a reduction rate (maximum reduction inclination angle) of the ultrasonic transmission amount per unit time is 50% or more.

3. The ink composition for ink jet recording according to claim 1, wherein a frequency of the ultrasonic wave is 2 MHz.

4. The ink composition for ink-jet recording according to claim 1, further comprising an acetylene glycol-based surfactant.

5. The ink composition for ink jet recording according to any one of claims 1 to 3, further comprising an amine-based surfactant.

6. The ink jet recording according to claim 4, wherein the content of the surfactant is 0.01 to 5% by weight based on the total weight of the ink composition for ink jet recording. For ink composition.

7. The ink composition for inkjet recording according to claim 1, wherein water or a water-soluble organic solvent is used as a main solvent.

8. The ink for ink jet recording according to claim 7, wherein the amount of the water or the water-soluble organic solvent is 1 to 40% by weight based on the total weight of the ink composition for ink jet recording. Composition.

9. The ink composition for ink jet recording according to any one of claims 1 to 8, further comprising a dye as a coloring material.

10. The ink composition for ink jet recording according to claim 9, wherein the dye is a disperse dye.

11. The ink jet according to claim 9, wherein the content of the dye is 0.1 to 10% by weight based on the total weight of the ink composition for ink jet recording. Recording ink composition.

1 2. The ink composition for ink jet recording according to any one of claims 1 to 8, wherein the ink composition contains a pigment as a coloring material.

13. The ink composition for ink jet recording according to claim 12, wherein the pigment is carbon black.

14. The ink composition for ink jet recording according to claim 12, wherein the content of the pigment is 3 to 15% by weight based on the total weight of the ink composition for ink jet recording. object.

15. The ink jet recording ink composition according to any one of claims 1 to 14, wherein the surface tension at 20 to 25 degrees Celsius is 30 to 40 dyne / cm. .

1 6. The ink composition for ink jet recording was measured by measuring the change in ultrasonic transmission intensity of a paper medium to which the ink composition for ink jet recording was applied using a dynamic absorption tester using ultrasonic waves. Method to evaluate the permeability of

17. The method according to claim 16, wherein the frequency of the ultrasonic wave is 2 MHz.