JPH0841396A - Recording ink - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent both nozzle clogging and early drying on the recording medium after recording. [Structure] A solvent mainly containing glycerin and propylene glycol, a pigment as a coloring material, and a dispersant,
A resin was mixed and a recording ink was prepared with a bead mill. When the content of glycerin is X% by weight and the content of propylene glycol is Y% by weight, 3 ≦ X
A recording ink satisfying all three expressions of ≦ 25, 3 ≦ Y ≦ 47, and 13 ≦ X + Y ≦ 50 is prepared. In the ink jetting device using this recording ink, good printing can be performed without causing clogging, the ink dries quickly after printing, and water resistance, abrasion resistance, and finger touch are excellent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording ink prepared by dispersing a pigment as a coloring material in a solvent containing water, glycerin and propylene glycol.

[0002]

2. Description of the Related Art Conventionally, as inks used in an ink jet recording system, as disclosed in JP-A-63-51485, JP-A-63-56575, JP-A-1-198671, etc., Various water-soluble dyes are dissolved in water alone or in a solvent consisting of water and a water-soluble solvent, and various additives are added as necessary, which is the mainstream. Described as dye ink). When printing was actually performed using dye ink, there were problems such as poor water resistance and light resistance of the recorded image on the recording medium.

Therefore, in order to improve the water resistance and light resistance of a recorded image, which is a problem of dye ink, an ink using a pigment such as carbon black or diazo yellow instead of a dye as a colorant (hereinafter referred to as a pigment ink). Is described in JP-A-57-57.
10660, JP-A-57-10661, JP-B-1-15542, JP-A-2-255875, and JP-A-2-276876. The pigment ink is superior in water resistance to the dye ink because the pigment ink adheres to a recording medium such as paper by using a resin or the like. Further, since the pigment has a lower reactivity to light than the dye, the light resistance of the pigment ink is superior to that of the dye ink.

By the way, the ink jet recording system is
An extremely thin channel is filled with ink, and a physical force is momentarily applied to the channel to eject a droplet of ink from the nozzle at the tip of the channel, and the droplet is covered by paper or the like. This is a method of recording by landing on a recording medium. In this ink jet recording method, the solvent may be evaporated in the nozzles, and the pigment may remain, resulting in clogging of the nozzles, making recording impossible. Therefore, a low-volatile water-soluble solvent is generally added to the inkjet recording ink for the purpose of preventing nozzle clogging.

[0005]

By the way, the recording ink is not limited to the ink jet recording system, and after the recording ink is recorded, it should be dried immediately so that the printer and the user's hand are not contaminated by the ink. Is required. However, when a low-volatile solvent is added to the ink, the solvent component is hard to evaporate on the recording medium even after recording, and thus quick drying after recording cannot be realized.

The present invention has been made to solve the above-mentioned problems, and provides a recording ink which realizes both prevention of nozzle clogging and early drying on a recording medium after recording. To do.

[0007]

In order to achieve this object, in Claim 1 of the present invention, a recording ink is prepared by dispersing a pigment as a coloring material in a solvent containing water, glycerin and propylene glycol. Therefore, the content of glycerin is X% by weight, and the content of propylene glycol is Y.
In terms of weight%, the following three formulas, 3 ≦ X ≦ 25, 3
It is characterized by satisfying all of ≦ Y ≦ 47 and 13 ≦ X + Y ≦ 50.

In claim 2, the glycerin content and the propylene glycol content are the following two formulas:
It is characterized in that all of 10 ≦ X ≦ 20 and 30 ≦ X + Y ≦ 40 are satisfied.

According to a third aspect of the present invention, it is used in an ink ejecting apparatus for ejecting ink to print on a recording medium.

[0010]

In the recording ink of the present invention having the above constitution, when the content of glycerin is X% by weight and the content of propylene glycol is Y% by weight, the following 3
Three expressions, 3 ≦ X ≦ 25, 3 ≦ Y ≦ 47, 13 ≦ X + Y ≦
By filling all 50, clogging of the nozzles is prevented, and the recording medium after recording is dried early.

[0011]

EXAMPLES The recording ink of the present invention is a recording ink composed mainly of water, a solvent containing glycerin and propylene glycol, and a pigment as a colorant. Generally, a dispersant and other Additives are also added. The dispersant disperses the pigment in a solvent, and the additive prevents aggregation of pigment particles and improves water resistance after printing.

The solvent which can be used in the recording ink of the present invention is a mixture of water, glycerin and propylene glycol.

The pigment that can be used in the recording ink of the present invention is not particularly limited. For example, for black and white, carbon blacks such as furnace black, lamp black, acetylene black and channel black can be used. , Or metals such as copper, iron and titanium oxide, and organic pigments such as altonitroaniline black. Further for colors, toluidine red, permanent carmine FB, fast yellow AAA, disazo orange PMP, lake red C, brilliant carmine 6B, phthalocyanine blue, quinacridone red, dioxane violet, pictoria pure blue, alkali blue toner, first yellow 10
G, Disazo Yellow AAMX, Disazo Yellow AAO
T, disazo yellow AAOA, yellow iron oxide, disazo yellow HR, orthonitroaniline orange, dinitroaniline orange, vulcan orange, toluidine red, chlorinated para red, brilliant fast scarlet, naphthol red 23, pyrazolone red, barium red 2B, calcium red 2B, Strontium red 2B, manganese red 2B, barium lysosome red, pigment scar red 3B rake, rake bordeaux 10B, anthocin 3B rake, anthocin 5B
Lake, Rhodamine 6G Lake, Eosin Lake, Bengal, Fafthor Red FGR, Rhodamine B Lake, Methyl Bio Red Lake, Dioxazine Bio Red, Basic Blue 5B Lake, Basic Blue 6G Lake, Fast Sky Blue, Alkali Blue R
Toner, Peacock Blue Rake, Navy Blue, Ultramarine, Reflex Blue 2G, Reflex Blue R, Brilliant Green Lake, Diamond Green Thioflavin Lake, Phthalocyanine Green G, Green Gold, Phthalocyanine Green Y, Iron Oxide Powder, Rust, Zinc Flower , Titanium oxide, calcium carbonate, clay, barium sulfate, alumina, alumina white, aluminum powder,
Bronze powder, daylight fluorescent pigment, pearl pigment, naphthol carmine FB, naphthol red M, permanent carmine FB, Fastero G, disazo yellow AAA, dioxane bio red, alkali blue G toner, etc. Processed pigments such as graft carbon can be used. Two or more of these may be mixed depending on the case.

As the dispersant, an anionic surfactant,
A cationic surfactant, an amphoteric surfactant, a nonionic surfactant, a high molecular surfactant, a high molecular polymer, etc. can be used.

As the anionic surfactant, alkyl sulfate, polyoxyethylene alkyl ether sulfate and the like can be used.

As the cationic surfactant, alkyl trimethyl ammonium chloride, dialkyl dimethyl ammonium chloride and the like can be used.

As the amphoteric surfactant, alkyl dimethylamino acetic acid betaine, alkyl dimethyl amine oxide, alkyl carboxymethyl hydroxyethyl imidazolium betaine and the like can be used.

As the nonionic surfactant, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene, polyoxypropylene glycol, polyoxypropylene alkyl ether and the like can be used.

The high molecular weight surfactant may be a high molecular weight polyurethane or polyester type, and the high molecular weight polymer may be a functional group having affinity for the pigment (eg, carbonyl group,
Those having an amino group) can be used.

Further, a water-soluble resin can be used as a dispersant. Examples thereof include cellulose resin, acrylic resin, silicone resin, vinyl resin and the like. These water-soluble resins can also be added as a fixing agent for fixing the pigment to the recording medium.

In addition, if necessary, a pH adjusting agent is used. Examples of the pH adjusting agent include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, ethanolamine, diethanolamine and triethanolamine. , Lower alkanolamines such as propanolamine, ammonium hydroxide, potassium dihydrogenphosphate and the like can be used.

Further, phenolic compounds, sodium benzoate and the like can be used for the purpose of antifungal and antiseptic, and ethylenediaminetetraacetic acid (EDTA) and the like can be used for the purpose of rust prevention.

Although the solvent, pigment, dispersant, and other components have been exemplified above, the present invention is not limited to these examples.

Specific examples and comparative examples of the recording ink of the present invention will be described below.

First, a method of manufacturing the recording ink of Example 1 shown in Table 1 will be described. Dispersant BYK-15 in a solvent consisting of pure water, glycerin, and propylene glycol.
4. Dissolve the resin polyvinyl alcohol B03, then add the pigment PRINTEX90 and disperse using a bead mill. The ink of Example 1 is obtained through the above processes. The other examples and comparative examples were similarly manufactured. The manufacturing method is not limited to this method.

Tables 1 to 3 show Examples 1 to 18 according to the present invention.
And the composition of Comparative Examples 1-18 was shown.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

Next, Examples 1 to 18 and Comparative Examples 1 to 1
The following items were evaluated for each ink prepared as No. 18.

First, the dry state of the nozzle before recording (hereinafter referred to as nozzle drying) was evaluated. Nozzle drying was evaluated by filling ink into the above-mentioned narrow flow path for ejecting ink and leaving it for recording by measuring the time for which recording is possible. The criteria are as follows.・ Recording is possible even if left for 120 seconds or longer.
(Excellent) ・ Recording is impossible when left for 60 seconds or longer and less than 120 seconds ... ○ △ (Good) ・ Recording is not possible when left for 30 seconds or longer but less than 60 seconds ... △ ( No) ・ Recording is impossible if left for less than 30 seconds ...
X (Poor) Next, the dry state on the recording medium (hereinafter referred to as paper surface dryness) was evaluated. The evaluation of paper surface dryness is based on the copy paper (X
The ink was applied to EROX (L paper) at a rate of 1.5 mg / square centimeter, and the time until the ink was dried to the point where it was not touchable with the hand was measured. The evaluation criteria are as follows.・ Ink will not stick to your hands within 10 seconds .... ○
(Excellent) ・ Ink is not accessible after 10 seconds to less than 15 seconds ・ ・ ・ ・ ○ △ (Good) ・ Ink is unavailable after 15 seconds to less than 20 seconds ・ ・ ・ ・・ ・ △ （Not possible） ・ Ink gets in your hand after 20 seconds
--- (Poor) It is desirable that the two evaluation items shown so far be given an excellent or good evaluation.

The actual evaluation results are shown in Tables 4 and 5.

[0033]

[Table 4]

[0034]

[Table 5]

As shown in Table 4, Examples 1 to 1
In the case of the ink of No. 8, both nozzle drying and paper surface drying are both excellent or good, and excellent properties are shown in all items. Therefore, when the content of glycerin and the content of propylene glycol contained in the ink are X% by weight and Y% by weight, respectively, in the inks of Examples 1 to 18, the content of glycerin and propylene glycol is 3%.
All three expressions of ≦ X ≦ 25, 3 ≦ Y ≦ 47, and 13 ≦ X + Y ≦ 50 are satisfied.

The inks of Examples 8, 9, 12, and 13 are excellent in both nozzle drying and paper surface drying, and show particularly excellent properties. Examples 8, 9, 1
In the inks Nos. 2 and 13, the content of glycerin and propylene glycol was 10 ≦ X ≦ 20, 30 ≦ X + Y ≦ 40.
The two expressions of are all satisfied.

On the other hand, as shown in Table 5, in Comparative Examples 1, 6, and 8, neither nozzle drying nor paper surface drying is impossible or defective, which is significantly inferior to Examples 1-18. There is. In each of Comparative Examples 1, 6 and 8, the total amount of glycerin and propylene glycol is smaller than that of Examples 1 to 18. Therefore, Comparative Examples 1, 6, 8
The ink of Example 1 is used for both nozzle drying and paper surface drying.
The reason why it is inferior to 18 is the lack of the total amount of glycerin and propylene glycol.

Further, in Comparative Examples 2 to 5, the paper surface drying is good, but the nozzle drying is not possible, which is inferior to Examples 1 to 18. Comparative Examples 2-5
The amount of propylene glycol in the ink of
8 is used, or a slightly larger amount is used, but glycerin is not used, or is used in a very small amount. Therefore, the reason why the inks of Comparative Examples 2 to 5 cannot be dried with nozzles is that the amount of glycerin is small.

In Comparative Examples 7 and 9 to 18, the nozzle drying was excellent or good, but was poor or poor in the paper surface drying, and was inferior to Examples 1 to 18. Among these, in Comparative Examples 10 and 12,
The amount of glycerin is the same as in Examples 1-18, but only a small amount of propylene glycol is used. On the other hand, in Comparative Examples 7, 9, 11, and 13, the total amount of glycerin and propylene glycol was larger than that in Examples 1 to 18, and in Comparative Examples 15 to 18, the propylene glycol amount was as in Examples 1 to 18. Similarly, the amount of glycerin in Example 1
It is more than ~ 18. In Comparative Example 14, the amount of glycerin is large and the amount of propylene glycol is small as compared with Examples 1-18. Therefore, the reason why the inks of Comparative Examples 7 and 9 to 18 are inferior in terms of drying on the paper surface is any one of the following three: excess glycerin amount, insufficient propylene glycol amount, excessive total amount of glycerin and propylene glycol This is due to two or more factors.

As described above, in the recording inks of Examples 1 to 18, which had excellent evaluation results, the glycerin content was X% by weight and the propylene glycol content was Y% by weight.
, 3 ≦ X ≦ 25, 3 ≦ Y ≦ 47, 13 ≦ X
Since all three expressions of + Y ≦ 50 are satisfied, nozzle clogging is prevented, and drying on the paper surface is fast.

Further, the recording inks of Examples 1 to 18 described above were prepared by using the shear mode type disclosed in JP-A-2-150355, the Kaiser type disclosed in Japanese Patent Publication No. 53-12138, and the special inks disclosed in Japanese Patent Publication No. 53-12138. When printing was performed using the thermal jet type ink jet device disclosed in Japanese Patent Publication No. 61-59914, good printing was possible without nozzle clogging, and the ink was dried after printing. It was fast, and was excellent in water resistance, abrasion resistance and finger touch.
Therefore, the inside of the printer and the hand of the user are not contaminated by the ink on the paper surface after printing.

In this example, the beads mill was used to prepare the ink, but a ball mill, sand mill, attritor, roll mill, agitator, Henschel mixer,
The ink may be prepared using a colloid mill, an ultrasonic homogenizer, an ultrahigh pressure homogenizer, a pearl mill, or the like.

[0043]

As is apparent from the above description,
According to the recording ink of the present invention, the content of glycerin is X% by weight and the content of propylene glycol is Y.
In terms of weight%, the following three formulas, 3 ≦ X ≦ 25, 3
Since ≦ Y ≦ 47 and 13 ≦ X + Y ≦ 50 are all satisfied, nozzle clogging is prevented and the recording medium after recording is dried early. In the ink jetting device using this recording ink, good printing can be performed without causing clogging, the ink dries quickly after printing, and water resistance, abrasion resistance, and finger touch are excellent. Therefore, the inside of the apparatus and the user's hand are not contaminated by the ink on the paper surface after printing. Further, the recording ink of the present invention has an effect that the high degree of light resistance and water resistance of the pigment can be utilized to achieve the preservation of the record for a long period of time.

Claims (3)

[Claims] 1. A recording ink comprising a pigment as a colorant dispersed in a solvent containing water, glycerin and propylene glycol, wherein the content of glycerin is X% by weight and the content of propylene glycol is Where Y is% by weight, the following three formulas: 3 ≦ X ≦ 25, 3 ≦ Y ≦ 47, 13 ≦ X + Y ≦ 50 are all satisfied. 2. The recording ink according to claim 1, wherein the glycerin content and the propylene glycol content satisfy all of the following two equations: 10 ≦ X ≦ 20 and 30 ≦ X + Y ≦ 40. . 3. The recording ink according to claim 1, which is used in an ink ejecting device that ejects ink to print on a recording medium.