JPH02209976A - Water-in-oil type ink composition for stencil printing - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing an oily component containing a resin component, colorant, specified surfactant and water, suitable for printing using a natural permeating central cylinder type stencil rotary press and having a relatively low viscosity. CONSTITUTION:The objective composition containing (A) an oil component which may contain a resin component, (B) a colorant, (C) a surfactant using a hydroxy fatty acid ester of a polyhydric alcohol consisting of polyglycerol, saccharides or sugaralcohols and (D) water. Furthermore, the amounts of the components are preferably 10-40wt.% component (A), 1-10wt.% component (B), 3-35wt.% component (C) and 25-75wt.% component (D).

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Object of the invention (industrial application field)
However, a water-in-oil ink composition for stencil printing with a relatively low viscosity, especially a water-in-oil ink composition suitable for printing using a natural penetration type (non-pressure type) single cylinder rotary printing press for stencil printing. The present invention relates to a type ink composition. In this specification, "water-in-oil type emulsion ink" is abbreviated as "water-in-oil type ink", and furthermore, "water-in-oil type" may be referred to as "VO type" hereinafter. be.

(Prior Art) Various types of VO type quick-drying stencil inks have been proposed in the past. For example, Tokko Akira! ≠−231,0/
The VO type ink described in the publication uses a roller-like device to apply pressure from inside the plate cylinder to transfer the ink layer adhering to the printing press's base paper or fabric onto the printing paper surface. As can be seen from this, it is assumed that the ink has a significantly high viscosity. In addition, the reason why this ink is considered to have a high viscosity is that: ・Common fatty acid esters of sorbitan (for example, sorbitan oleate) are used as surfactants.
We can't help but infer this from the fact that it is used and the ink has a high water content (70% water content in the example). By the way, in this type of VO type ink, it is possible to make it dry quickly by increasing the water concentration, but the surfactant used in this case is ordinary fatty acids that do not contain hydroxyl groups such as carrubitan oleate (hereinafter referred to as " If the surfactant is an ester nonionic surfactant (sometimes referred to as "common fatty acid"), the viscosity of the ink will be extremely high.

Also, Tokko Akira! No. 2-7370 also describes a vO type ink, which also uses a fatty acid ester of sorbitan as a surfactant.
Moisture content listed in the same example! Even if the viscosity is low in mass production of O1%, for example, the water content is jO~6
It is presumed that if the ink is as valuable as 0%, it will result in a highly viscous ink with extremely low fluidity.

Furthermore, since the inks described in the above patent publications use ordinary fatty acid esters of sorbitan as surfactants, their allowable water-holding capacity is low, and when inks with high water content are used, emulsion stability is poor. However, it has the disadvantage that it aggregates during storage for a relatively short period of time and separates the oily component.

On the other hand, the printing method using the above-mentioned natural penetration type (pressureless type) single-cylinder rotary printing press for stencils is a method of printing without applying any pressing force to the ink. In other words, in this printing method, the ink injected into the plate cylinder permeates and passes through the surface of the plate cylinder and the base paper by centrifugal force when the plate cylinder rotates, and is transferred to the paper, resulting in printing. The system is such that However, the ink used for printing with this method must be fluid, have good permeability, and have a low viscosity in order to print well. If high viscosity ink with low fluidity is used, the ink will not be able to pass through the board or screen, making printing difficult, and even if printing is possible, the print will be blurred or the color shading will be significant. or a blurred print with poor resolution may be obtained.

On the other hand, as mentioned above, moldable inks dry quickly when the water content is high, which can increase printing speed.
However, when the water content is increased, the viscosity of the ink also increases (poor fluidity), making it impossible to print using the above-mentioned single cylinder rotary printing press for natural penetration stencil printing. , the storage stability of the ink becomes significantly worse.

(Problems to be Solved by the Invention) The present invention has stable emulsification for a long period of time even when the water content is high, dries quickly, has a relatively low viscosity, has high fluidity, and is suitable for stencil paper and screens. It is an object of the present invention to provide a printing ink composition which is easily permeable and therefore can be applied to high-speed printing using a single cylinder rotary printing press for natural penetration type stencils.

(b) Structure of the Invention As a result of various studies to solve the above-mentioned problems, the inventors of the present invention have discovered that by preparing an ink type ink using a specific surfactant derived from oxyfatty acid. , an ink with extremely high water-holding properties is obtained, and even though the ink has a high water content and therefore dries quickly, it has a relatively low viscosity and high fluidity, and easily penetrates stencil paper and screens.
It was discovered that an ink with stable emulsification for a long period of time can be obtained and the above object can be achieved, and the present invention was achieved.

The first water-in-oil ink composition for stencil printing of the present invention includes:
In a water-in-oil ink comprising an oily component that may contain a resin component, a coloring agent, a surfactant, and water, the surfactant is a polyhydric alcohol selected from polyglycerin, sugars, and sugar alcohols. The ink is characterized by using at least one type of oxyfatty acid ester.

In addition, the water-in-oil ink composition for stencil printing of the second invention includes a water-in-oil ink containing an oily component that may contain a resin component, a coloring agent, a surfactant, and water. This ink is characterized in that it uses at least one oxyfatty acid ester of a polyhydric alcohol selected from polyglycerin, saccharides, and sugar alcohols as an agent, and contains a polyhydric alcohol.

As the oil component in the ink composition of the present invention, various vegetable oils, mineral oils, hydrocarbon-based synthetic oils, appropriate mixtures thereof, and the like can be used. Further, the oily component can be used in combination with a resin component by appropriately dissolving the resin component, if necessary. The proportion of oily components is
The amount including the resin component based on the ink composition is 10-
≠O! 25%, preferably 73-35% by weight.

Examples of vegetable oils for the oily component include castor oil,
Vegetable oils commonly used as oily components for printing inks can be used, such as dehydrated castor oil, linseed oil, tall corn oil, soybean oil and cottonseed oil.

In addition, as mineral oil for oily components, for example, the boiling point is 2.
00~3! Examples include various petroleum oils such as OC petroleum solvents, spindle oil, liquid paraffin, motor oil, gear oil, machine oil, and lubricating oil.

The hydrocarbon synthetic oil for oily components is, for example, a synthetic oil obtained by polymerization or copolymerization of unsaturated hydrocarbons such as ethylene, propylene, and butene, and has an average molecular weight of 2oo.

I can give you something.

Further, resin components that can be used in combination with oil-based components by dissolving them in the oil-based component include, for example, alkyd resins (e.g., reaction products of phthalic anhydride and linseed oil, reaction products of isophthalic acid and soybean oil, rosin (modified alkyd resin, etc.), polymerized castor oil, rosin, polymerized rosin, hydrogenated rosin, rosin ester, hydrogenated rosin ester terpene resin, petroleum resin, rosin-modified phenolic resin, etc.

Its rosin esters and hydrogenated rosin esters,
Examples include maleated products of methyl ester, ethyl ester, ethylene glycol ester, glycerin ester, pentaerythritol ester, chrycerin ester, and maleated products of hhentaerythritol ester. In addition, as the terpene resin, for example, α
-Pinene heavy metals, β-pinene polymers, maleated products of these polymers, etc.

Examples of the petroleum resin include resins obtained by polymerizing unsaturated hydrocarbons such as monoolefins and diolefins, and chilled products of the resins.

In addition, these rosin, rosin ester, polyterpene, rosin-modified phenolic resin, petroleum resin, etc. are usually
Since it is mostly solid, it is mixed with a liquid oily component, dissolved in the oily component by an appropriate means, and liquefied at room temperature before use.

As the colorant in the ink composition of the present invention, all colorants commonly used for printing inks can be used. for example,
Examples include inorganic and organic pigments such as carbon black, titanium oxide, calcium carbonate, barium sulfate, cyanine blue, cyanine green, and lake red. The proportion of the colorant used is usually 1 to 70% by weight, preferably 3 to 7% by weight, based on the ink composition.

The surfactant used in the ink composition of the present invention is a specific nonionic surfactant such as at least one oxyfatty acid ester of a polyhydric alcohol selected from polyglycerin, sugars, and sugar alcohols; This is the most distinctive feature of the present invention. If such a specific nonionic surfactant is used, an ink composition with extremely high water-holding power can be obtained, and even if the ink composition has a high water content in order to dry quickly, it has a relatively low viscosity. The resulting ink is low in weight and has excellent storage stability. In the present invention, the specific nonionic surfactant may be used in combination with other nonionic surfactants depending on the case. The proportion of these nonionic surfactants used in the present invention is usually 3 to 35% by weight, preferably 3 to 23% by weight, based on the ink composition.

The oxyfatty acid constituting the surfactant used in the present invention has at least one hydroxyl group in addition to a carboxyl group.

Such oxyfatty acids preferably have carbon atoms of g to 21
IL saturated or unsaturated oxyfatty acids, specific examples of which are oxylauric acid, oxymyristic acid, oxybalmitic acid, oxystearic acid, oxybehenic acid, oxytridecanoic acid, oxypentadecanoic acid, oxystearic acid, and oxyoctadecane. Examples include oxidinonadecanoic acid, oxyarachic acid, ricinoleic acid, and ricieraidic acid. These oxyfatty acid polymers can also be used as the oxyfatty acid constituting the surfactant of the present invention.

In addition, polyhydric alcohols constituting the surfactant used in the present invention include polyglycerin (polymerized mole number n = λ ~), such as diglycerin, triglycerin, hexaglycerin, decaglycerin, etc.), saccharides (such as glucose, fructose, sucrose, maltose, etc.), and sugar alcohols (eg, sorbitol, maltitol).

Specific examples of surfactants used in the present invention include polyglycerin (degree of polymerization n = 2 to 7μ) polyricinoleic acid (n = 2 to /+) ester, polyglycerin (n = 2 to
/+) polyricinoleic acid (n=2~IO) poly(n=
2~/+) ester, sucrose polyricinoleic acid (n =
3-g) ester, sorbitol polyricinoleic acid (n = 3-6) ester, polyglycerin (n =,
2-/, 2) Poly-7,2-oxyoctadecanoic acid (n
=3~/4 esters and the like. These surfactants may be used alone or in combination of two or more, and in some cases, other nonionic surfactants may be used within a range that does not impair the effects of the present invention. It is also possible to use them together.

The polyhydric alcohol constituting the ink composition of the present invention (second invention) is preferably an alcohol having three or more hydroxyl groups, and one type or two or more types of the polyhydric alcohol may be used. It may be a mixture of. Specific examples of the polyhydric alcohol include glycerin, trimethylolpropane, butanetriol, methylpropanetriol, hexanetriol, and polyglycerin (n=2~/
2, such as diglycerin, triglycerin, hexaglycerin, etc.), erythritol, and pentaerythritol sodium.

The proportion of polyhydric alcohol used in the present invention (second invention) is 20% by weight or less based on the ink composition. When a polyhydric alcohol is blended, the storage stability (emulsion stability) of the ink composition can be improved at low temperatures such as below the OC or at high temperatures such as ≠0C or above.

The amount of water constituting the ink composition of the present invention is 25 to 7J"i amount%, preferably 3j to 11j, based on the ink composition.
Weight%. The water may be any water such as tap water, purified water or deionized water.

Next, some typical embodiments for preparing the ink composition of the present invention will be described below.

■ Mix the coloring agent with some or all of the oil-based ingredients and knead it with three rolls, then mix with the surfactant, polyhydric alcohol blended as necessary, and the rest of the oil-based ingredients, and knead it with three rolls. Pass 7 times.

Next, all of the water is gradually added to the mixture while stirring it in a stirrer, and the mixture is further emulsified in an emulsifier to form an emulsion tank. In addition, instead of processing with an emulsifying machine,
It may be passed through a triple roll or processed with a sand mill or the like.

■ Mix the coloring agent, oily component, surfactant, and polyhydric alcohol added as necessary, and knead the mixture using a three-roll mill, sand mill, or attritor, and then stir the mixture using a stirrer to remove all the water. After gradually adding it, it is further emulsified with an emulsifier to form a separate emulsion. In addition, instead of processing with an emulsifying machine, it may be passed through three rolls or processed with sand-ol or the like.

■ Mix the colorant, oily component, surfactant, and polyhydric alcohol to be blended as necessary, and knead with a triple roll or sand mill. Add all the water to the mixture at once, and mix with a homomixer. Stir and emulsify to form a separate emulsion. Note that instead of processing with a homomixer, it may be passed through a three-roll mill or may be processed with a sand mill.

■ A mixture of colorant, oily component, surfactant, and polyhydric alcohol blended as necessary is mixed with a stirrer, and all the water is gradually added to emulsify it to form a test emulsion.

Next, the emulsions of Te and So are passed through a triple roll or processed with a sand mill to complete the emulsification and dispersion.

■ Mix the colorant, oily component, and surfactant, pass the mixture through three rolls, or process it with a sand mill and knead it, then add all the water or polyhydric alcohol blended as necessary. of water is gradually added, and the mixture is further processed in an emulsifier to emulsify it into a separate emulsion. In addition, instead of processing with an emulsifier, pass it through three rolls,
Alternatively, it may be processed with a sand mill.

In addition, in each aspect of preparing the above ink composition,
When a liquid resin component is blended, the liquid resin component may be used in combination with an oily component. In addition, when blending a solid resin component, the solid resin component is mixed with an oil component and heat treated at a temperature above the softening point of the resin to completely dissolve the resin component into the oil component and uniformly dissolve the resin component into the oil component. Convert it before using it. Further, the water may be used as hot water (for example, hot water of jO to 60C) as necessary, or a homomixer may be used instead of the stirrer.

The ink composition of the present invention generally has a viscosity of 3,000 to ≠0,000 cp at the operating temperature (J to 3JC) when using a natural penetration type rotary stencil printing machine.
It is preferable to set it to s. Note that this viscosity is a value measured using a Brookfield viscometer (BL type) under the conditions that the rotor number is 3 or ≠ and the rotation speed is 6 rpm.

In general, the drying speed of different type inks is approximately proportional to the water content, but with conventional %10 type ink, the viscosity increases significantly when the water content is increased to increase the drying speed. It could not be used in a printing method using a rotary printing press for stencil plates.

However, since the vO type ink composition of the present invention is prepared using a specific surfactant derived from oxyfatty acid, it is an ink with extremely high water-holding power, and has a high water content (e.g. Moisture content t≠θ~70% by weight
) ink can be made to have a relatively low viscosity, so even when using a natural permeation single-cylinder stencil rotary printing machine, it has good penetration and can be printed at high speed. In this case, as shown in Examples/--B, clear printing with no color unevenness or bleeding and excellent resolution of the printed image can be obtained.

For example, in the case of ink with the same water content, the ink composition of the present invention has a significantly lower viscosity ( Example/
and Comparative Example/, Example 2 and Comparative Example 3, or Example 3 and Comparative Example≠). Furthermore, in the case of inks of the same viscosity, the ink composition of the present invention can have a significantly higher water content than conventional inks (see Examples/Comparative Examples).
.

In addition, in conventional paste-type inks, when the water content is increased, the emulsion stability, especially the stability over time, decreases, but the ink composition of the present invention has a long-term stability compared to conventional inks of this type.
For example, it has excellent stability (for example, for more than 6 months).
and Comparative Example/or Example 3 and Comparative Example≠).

As described above, the reason why the ink composition of the present invention is able to maintain a relatively low viscosity even when the water content is increased and has excellent storage stability is that the specific surfactant used in the ink composition is highly resistant to viscosity. The main reason is that it provides an emulsion with high hydropower, but another reason is that the specific surfactant used in the present invention is generally a polymeric surfactant with a molecular weight of 1000 or more and has high emulsifying power. This is thought to be a contributing factor.

Furthermore, the ink composition of the present invention (second invention) has extremely high stability at low temperatures. In other words, if an ink composition that does not contain polyhydric alcohol is stored at a temperature below OC, the emulsification will break due to freezing and the ink will separate into two layers, making it unusable, but ink compositions that contain polyhydric alcohol will does not cause two-layer separation due to demulsification even upon freezing (see Example λ and Comparative Example 3).

In addition, the ink composition containing polyhydric alcohol is tt
It also has excellent long-term storage stability at high temperatures such as oc.

Since the ink composition of the present invention has a relatively low viscosity even with a high water content, it is particularly suitable for printing using a natural penetration type mono-barrel rotary stencil printing press, but it is suitable for printing using other stencil printing presses (e.g. Of course, it can also be used for printing using a single-cylinder rotary printing press, a multi-cylinder rotary printing press, a manual printing press, etc.).

(Examples etc.) Below, Examples and Comparative Examples will be given and further explained in detail. In addition, "part" and "%" stated in these examples are
Means weight percentage and weight %, respectively.

Example/ Approximately 3 parts of rosin modified phenol resin and 7 parts of soybean oil
To the mixture heated at 2 qoc for 7 hours, 77 parts of spindle oil and 75 parts of Hexaglycerin Sha Polyline Root (n=j) as a surfactant were added in this order and stirred.
The mixture was made homogeneous, and then 3 parts of carbon black was added to the mixture and mixed, and the mixture was kneaded using three rolls. Next, while stirring the mixture with a stirrer, 36 parts of water (based on the ink composition) was gradually added and emulsified, and then passed through three rolls to obtain a molded ink composition. . The viscosity of this ink composition was determined using a BL type viscometer and shown in Table 1 as a round value.

Comparative Example/An ink was produced in the same manner as in Example/, except that the surfactant in Example/ was replaced with sorbitan monooleate. The viscosity of the obtained ink was as shown in Table 7.

Comparative Example 2 Water usage details (approximately 30% of the ink composition)
An ink was produced in the same manner as in Comparative Example except for the following changes. The viscosity of the obtained ink was as shown in Table 1.

Using each of the ink compositions obtained in Examples/Comparative Examples/--C, printing was performed using a stencil printing machine (natural osmosis type rotary printing machine).

In other words, Garaken Roneo rotary stencil printing machine (GOM-
g70), and vinyl base paper (GSM-2) is used for the plate.
Printing was carried out using high-quality paper and at a printing speed of ♂0 sheets/min. The results were as shown in Table/.

As can be seen from Table 7, the ink composition of Example 1 had a clear and appropriate print quality in color tone and density, and had no bleeding or color unevenness. Further, the dry time to the touch was 75 seconds or less. Further, no abnormality was observed in the ink composition even after it was left for 6 months.

On the other hand, since the ink of Comparative Example/ had the same water content (33%) as Example 1, the ink viscosity was too high and printing was impossible.

In addition, since the water content of Comparative Example Ink was lowered (approximately 30%), the viscosity was similar to that of Example, and printing was possible, but the drying speed was slow and it took a long time to dry to the touch. is 70
If the print was printed for more than a minute, the stains caused by ants and the back of the print became noticeable, making it impractical as a printed matter. Further, the ink caused oil separation after being left for about one week, making it impractical.

Example Co/30 20 parts of spindle oil, 75 parts of octaglycerin polylysyllate (n=4) as a surfactant, and 3 parts of Lake Red were mixed and homogenized by stirring with a stirrer.
A mixture of 975 parts of grise and 57 parts of water was added thereto, treated with a homomixer to form an emulsion, and passed through three rolls seven times to obtain an ink composition.

Comparative Example 3 ←Gantouji Temple→ /30 Using 20 parts of spindle oil, 13 parts of Solpita monooleate as a surfactant, 3 parts of Lake Red, and 62 parts of water, an ink composition was prepared in the same manner as in Example -. I got something.

The viscosity of each ink composition obtained in Example 3 and Comparative Example 3 was measured in the same manner as in Example. In addition, 'C' in room temperature storage C2 of each ink composition! 1 (left undisturbed for 3 days), and stored at room temperature and then frozen (
-ioc temperature for 3 days and then returned to room temperature. ), examples/! A printing test similar to that for /C was conducted. The results were as shown in Table 1.

Note 1 to Table 2: Since the ink composition of Example-1 contains 3% glycerin, the aqueous component content is 62%.

As can be seen from the results in Table 2, the ink composition of Example C had a viscosity suitable for printing.

In addition, the ink composition after storage at room temperature (before frozen storage),
The results of printing tests performed on the ink compositions and the ink compositions after frozen storage showed that printing was good in both cases.

On the other hand, the ink composition of Comparative Example 3 had a high viscosity that was not suitable for printing. In addition, the ink compositions after storage at room temperature and after storage in a frozen state could not be used for printing as shown in the table.

Example 3 Alkyd resin (reaction product of linseed oil and phthalic anhydride) part J, rosin ester! ; part, /30 spindle oil IO part, 1! , 7 parts of O spindle oil, 73 parts of decaglycerin polylysyllate (n=za) as a surfactant,
3 parts of Lake Red were mixed and homogenized by stirring with a stirrer, then 33 parts of water was added thereto, treated with a homomixer to form an emulsion, and further passed through three rolls to obtain an ink composition. .

Comparative Example μ Glycerin dilysylte/! as a surfactant! An ink composition was prepared in the same manner as in Example 3, except that the same procedure was used as in Example 3.

The viscosity of each of the ink compositions obtained in Example 3 and Comparative Example≠ was measured in the same manner as in Example, and a printing test was conducted in the same manner. Further, after the inks of Example 3 and Comparative Example≠ were left to stand for 6 months, a printing test similar to that in Example/ was conducted. The results were as shown in Table 3.

Margin Table 3 Below, as shown in Table 3, the ink composition of Example 3 had a viscosity of /
The printing speed was as low as 4200 cps, and the printing test results were good for all items, with the dry-to-touch time being 75 seconds or less. In fact, this ink remains in good condition even after being stored for 6 months.
The printing test results using the ink after storage were also good.

On the other hand, the ink compositions of Comparative Examples≠ had extremely high viscosity and were impossible to print. Furthermore, this ink had poor storage stability, and oil separation occurred during storage for about one week.

Example DA alkyd resin (reaction product of linseed oil and 7-tar acid anhydride) j parts, rosin ester 3 parts, /j.

77 parts of spindle oil, 10 parts of 60 spindle oil, 20 parts of sorbitol tetralysylte, and 3 parts of Lake Red as a pigment were mixed and kneaded, and 10 parts of water was added and stirred with a high-speed stirrer to prepare an ink composition. Obtained.

Example! Alkyd resin (reaction product of linseed oil and phthalic anhydride) 4 parts IL, 3 parts rosin ester, /! Mix 0 spindle oil, 23 parts, sucrose hexalicylate lj parts, and 3 parts of phthalocyanine blue as a pigment, knead it, and mix it with water! Part Q was added and stirred using a stirrer, followed by processing in a sand mill for 30 minutes to obtain an ink composition.

Example 6 /jO Spindle oil 2 parts oil 3 parts Caglycerin octaricylate 2 parts polyoxyethylene (3 mol) Glycerin trilysylate! 1 part and 3 parts of phthalocyanine blue as a pigment were mixed and kneaded, 60 parts of water was added, and the mixture was stirred with a high-speed stirrer to obtain an ink composition.

The viscosity of each of the ink compositions obtained in Example <zXt and B was measured in the same manner as in Example, and a printing test was conducted in the same manner.

The results were as shown in Table t.

As shown in the margin table below, each of the ink compositions of Examples 1II to 6 had a low viscosity suitable for printing despite their high water content. In addition, all printing test results showed that good printed matter could be obtained.

(C) Effects of the invention The printing ink composition of the invention has the following excellent effects.

(1) Even if the ink composition has a high water content and therefore dries quickly, it has a relatively low viscosity and therefore has excellent permeability into paperboards and screens.

(11) Even with a high water content, the &upper emulsion ink composition has excellent long-term storage stability (emulsion stability).

(ili) As a result of achieving the effect of (1) above,
It is possible to print at high speed and with excellent image resolution using a natural penetration type (non-pressure type) single-cylinder stencil rotary printing press.

(1v) Those containing polyhydric alcohol are further OC
Even when stored at low temperatures below (for example -20"C), emulsion destruction does not occur, and the emulsion stability is excellent even when stored at high temperatures comparable to Hiro OC.

Claims (1)

[Scope of Claims] 1) A water-in-oil ink containing an oily component that may contain a resin component, a coloring agent, a surfactant, and water, wherein the surfactant is selected from polyglycerin, sugars, and sugar alcohols. 1. A water-in-oil ink composition for stencil printing, characterized in that it is made of at least one oxyfatty acid ester of a polyhydric alcohol. 2) The total amount of oily components that can contain resin components is 10
2. The ink composition of claim 1, wherein the ink composition comprises 1 to 10% by weight of colorant, 3 to 35% by weight of surfactant, and 25 to 75% by weight of water. 3) In a water-in-oil ink containing an oily component that may contain a resin component, a coloring agent, a surfactant, and water, the surfactant is a polyhydric alcohol selected from polyglycerin, sugars, and sugar alcohols. A water-in-oil ink composition for stencil printing, characterized in that it contains at least one oxyfatty acid ester and a polyhydric alcohol. 4) The total amount of oily components that can contain resin components is 10
~40% by weight, colorant from 1 to 10% by weight, surfactant from 3 to 35% by weight, polyhydric alcohol to 20% by weight or less, and water from 25 to 75% by weight. The ink composition described.