FR2680513A1 - PIGMENTED AQUEOUS INK COMPOSITION. - Google Patents

Abstract

The present invention relates to a pigmented aqueous ink comprising a pigment, a dispersant, water and an adduct of at least one polyalcohol and of an alkylene oxide, the polyalcohol being chosen from polyglycerine, glycerine , trimethylolpropane and their mixtures. The composition, which prevents deterioration of surface tension and has excellent drying resistance and lubricating properties, is particularly suitable as a pigmented aqueous ink composition for ballpoint pens ensuring regular writing performance and clean writing.

Description

FRAMEWORK OF THE INVENTION

  {i) Field of the Invention The present invention relates to an aqueous pigment ink composition More particularly, it relates to an aqueous pigment ink composition suitable for ballpoint pens.

  (iii Description of related art

  In a conventional pigmented aqueous ink for ballpoint pens, a pigment is dispersed as a coloring agent and water or a water-soluble solvent, such as glycol or glycerin, is the solvent which is the main component preventing drying of the ink (resistance to drying) at the tip of the ballpoint pen However, such a conventional ink has poor lubricating properties, so that the resistance to friction between a ball and a ball housing is important when the ball rotates during writing, which causes the following drawbacks The ball housing wears out and the ball retracts and is poorly secured or the ink flow becomes irregular, so that the writing performance decreases significantly To overcome these drawbacks, an attempt has been made to add a lubrication-improving agent, such as an unsaturated fatty acid or potassium oleate. On the other hand, Japanese Preliminary Patent Publication No. 63-234073 describes a ballpoint pen ink containing a dye and an adduct of polyglycerine and ethylene oxide and Japanese Preliminary Patent Publication No. 55 -106273 describes an aqueous ink composition for ballpoint pen containing a dye, an adduct of sorbitol or

  glycerin and a polyoxyalkylene and a fluorinated surfactant.

  In both publications, it is stated that these ballpoint pen inks have excellent lubricating properties and allow regular writing. However, when the dye is used with the alkylene oxide adduct, the lubricating properties are excellent, but a disadvantage is that the ink tends to drool In addition, Japanese published patent application No. 62-10547 describes a recording liquid suitable for an ink jet recording system containing a product of addition of glycerin and an alkylene oxide However, when using the recording liquid for a ballpoint pen, it is observed as disadvantages that the lubricating properties are not always

  satisfactory and that the dispersion of a pigment is not good.

SUMMARY OF THE INVENTION

  In the case of the aforementioned conventional methods, it is not possible to obtain sufficient lubricating properties and writing becomes impossible as a result of wear of the housing of the ball. In addition, certain practical problems also arise. obtains satisfactory lubricating properties, the surface tension of the ink deteriorates notably and the characters

traces are easily disturbed.

  An object of the present invention is to provide an aqueous pigmented ink for ballpoint pens making it possible to avoid an extreme deterioration of the surface tension and to prevent the written characters from blurring, with excellent properties of resistance to drying and having sufficient lubricating properties for a ball to rotate easily and to reduce friction on the ball housing, so that writing performance can be remarkably improved and writing

easy assured.

  The present inventors have carried out intensive research to solve the aforementioned problems and have thus discovered that when an adduct of a specific polyalcohol and an alkylene oxide is added to a pigmented ink composition, the The above object can be achieved The present invention

is based on this discovery.

  An aqueous pigment ink composition for ballpoint pens of the present invention is characterized in that it comprises a pigment, a dispersant, water and at least one adduct of a polyalcohol and an oxide of alkylene selected from the group consisting of an adduct of polyglycerin and an alkylene oxide, an adduct of glycerin and an alkylene oxide in which 1 to 150 moles of the oxide of alkylene are added to 1 mole of glycerin, an adduct of

  trimethylolpropane and an alkylene oxide and one of their mixtures.

  The first pigmented aqueous ink composition for ball point pens of the present invention is characterized in that it comprises a pigment, a dispersant, water and an adduct.

  polyglycerin and an alkylene oxide.

  The preferable example of this ink composition is a pigmented aqueous ink composition which comprises 0.5 to 40% by weight of a polyglycerin adduct and an alkylene oxide in which 1 to 60 moles of the alkylene oxide are added to 1 mole of polyglycerin having a degree of polymerization of 2 to 4, 2 to 30% by weight of a pigment, 0.1 to 10% by weight of a dispersant and 40 90% by weight of water relative to the total weight of

the composition.

  The second pigmented aqueous ink composition for ballpoint pens of the present invention is characterized in that it comprises a pigment, a dispersant, water and an adduct of glycerine and an oxide of alkylene in which 1 to 150 moles of

  the alkylene oxide are added to 1 mole of glycerin.

  The preferable example of this ink composition is a pigmented aqueous ink composition which comprises 0.5 to 40% by weight of an adduct of glycerin and an alkylene oxide, 2 to 30 % by weight of a pigment, 0.1 to 10% by weight of a dispersant and 40 to 90% by weight of water relative to the total weight of

the composition.

  The third pigmented aqueous ink for ballpoint pens of the present invention is characterized in that an adduct of trimethylolpropane and an alkylene oxide is added to a pigmented aqueous ink mainly composed of a pigment,

  a dispersant, a water-soluble solvent and water.

  The preferable example of this ink composition is a pigmented aqueous ink composition which comprises 0.5 to 40% by weight of an adduct of trimethylolpropane and an alkylene oxide in which 1 to 60 moles of the alkylene oxide are added to trimethylolpropane, 2 to 30% by weight of a pigment, 0.1 to% by weight of a dispersant and 40 to 90% by weight of water

  relative to the total weight of the composition.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

  An adduct of a polyglycerine and an alkylene oxide, which is used in a composition of the present invention, is an adduct in which 1 to 60 moles of an alkylene oxide are added to a polyglycerin having a degree of

  polymerization from 2 to 4, such as diglycerin and triglycerin.

  For example, it is possible, to obtain such an adduct, from 1 to 60 moles of alkylene oxide, of propylene oxide or of a mixture thereof to a polymer containing 1 mole of polyglycerine having a degree of polymerization from 2 to 4, and the content of the adduct of the polyglycerine and of the alkylene oxide is preferably from 0.5 to 40% by weight, better still from 1 to 30% by weight, relatively to the total weight of the composition When the content of the adduct is less than 0.5% by weight, it is not possible to obtain sufficient lubricating properties, so that one cannot hope for an improvement in the performance of writing Furthermore, when it is greater than 40% by weight, the viscosity of the ink increases and the flow of the ink is poor and does not

not suitable.

  The adduct of glycerine and alkylene oxide, which is used in the ink composition of the present invention, is an adduct in which 1 to moles of the oxide of alkylene are added to the glycerin For example, one can, to obtain such an adduct, add 1 to moles of ethylene oxide, propylene oxide or a mixture thereof with glycerin The content of the Addition product of glycerin and alkylene oxide is preferably from 0.5 to 40% by weight and better still from 1 to 30% by weight, relative to the weight of the composition. When the content of the adduct is less than 0.5% by weight, it is not possible to obtain sufficient lubricating properties, so that one cannot expect an improvement in writing performance. it is greater than 40% by weight, the viscosity of the ink increases and the flow of

  the ink is poor and not suitable.

  The adduct of trimethylolpropane and alkylene oxide, which is used in the ink composition of the present invention, is an adduct in which 1 to

  moles of the alkylene oxide are added to trimethylol-propane.

  One can for example, to obtain such an adduct, add 1 to 60 moles of ethylene oxide, propylene oxide or one of their mixtures with trimethylolpropane The content of the adduct of trimethylolpropane and alkylene oxide is preferably from 0.5 to 40% by weight and better still from 1 to 30% by weight, relative to the

weight of the composition.

  When the content of the adduct is less than 0.5% by weight, it is not possible to obtain sufficient lubricating properties, so that one cannot expect an improvement in writing performance. it is greater than 40% by weight, the viscosity of the ink increases and the flow of

  the ink is poor and not suitable.

  The adduct of the specific polyalcohol and the alkylene oxide in the ink composition of the present invention is prepared from alkylene oxide and the specific polyalcohol in a reaction catalyzed by an alkali in the presence of 'an excess of alkylene oxide. In this reaction, the alkylene oxide reacts first with the specific polyalcohol, then a complementary polymerization of

the alkylene oxide is carried out.

  In a pressure-resistant container, the internal atmosphere of which has been replaced by nitrogen, the specific polyalcohol and an alkali are introduced, then the alkylene oxide is added dropwise at a pressure of approximately 10 bars (10 kg / cm 2) and at a temperature of 100-1400 C. In the ink composition of the present invention, the adduct of the specific polyalcohol and the alkylene oxide can be mixed with a water-soluble organic solvent Examples of such a solvent include water-soluble polyalcohols, such as ethylene glycol, propylene glycol, diethylene glycol and glycerin; cellosolves, such as the ethylene glycol monomethyl ether (methylcellosolve) and the ethylene glycol monoethyl ether (ethylcellosolve); carbitols, such as the monomethyl ether of diethylene glycol (methylcarbitol) and the monoethyl ether of diethylene glycol (ethylcarbitol); and glycol ether esters, such as ethylene glycol monoethyl ether acetate These compounds can improve resistance to

drying out.

  The proportion of solvent & mix is generally 40% by weight or less, preferably 5 & 40% by weight, relatively

the total weight of the composition.

  There is no particular limitation on the nature of the pigment which can be used in the ink composition of the present invention and any mineral and organic pigments which have conventionally been used in a composition can be used. pigmented aqueous ink Examples of such a mineral pigment include titanium oxide, carbon black and metallic powders; and examples of the above organic pigments include azo lakes, insoluble azo pigments, azo chelate pigments, phthalocyanine pigments, perylene, perylene pigments, anthraquinone pigments, quinacridone pigments, lakes coloring,

  nitro pigments and nitroso pigments.

  Typical examples of the pigments that can be used include the following: Phthalocyanine Blue (CI 74260), Phthalocyanine Green (CI 74260), Hansa Yellow 3 G (CI 11670), Disazo Yellow GR (C I. 21100), Permanent Red 4 R (CI 12335) ), Brilliant Carmine 6 B (C I.

  15850) and Quinacridone Red (C I 46500).

  These pigments can be used separately or in combination of two or more and the proportion of pigment to be used is generally from 2 to 30% by weight, preferably from 5 to 15% by weight.

  weight, relative to the total weight of the composition.

  The dispersant in the composition of the present invention adheres to the surfaces of the pigment particles and allows the dispersion of the pigment in water. Examples of useful dispersants include nonionic and anionic surfactants and water soluble polymers, and it is preferred to use the latter water-soluble polymers. Examples of the nonionic surfactants include polyoxyalkylene higher fatty esters, partial fatty acid higher esters of

  polyalcohols and higher fatty esters of saccharide.

  Typical examples of non-ionic surfactants include fatty esters of glycerin, fatty esters of polyglycerin, fatty esters of propylene glycol, fatty esters of pentaerythritol, fatty acid esters of polyoxyethylenesorbitan, fatty acid esters polyoxyethylene sorbitol, polyoxyethylene glycerin fatty acid esters, polyethylene glycol fatty esters, polyoxyethylene alkylene ethers,

  polyoxyethylenephytosterols, polyoxyethylene-polyoxy- ethers

  propylene-alkyl, polyoxyethylenalkylphenyl ethers, polyoxyethylenic castor oil, polyoxyethylenelanoline, polyoxyethylenelanoline alcohol, polyoxyethylenalkylamine, fatty polyoxyethylenamides and polyoxyethylene alkyl formaldehyde condensates. Examples of anionic surfactants include alkylated sulfonates of higher fatty acid amides and alkylallylsulfonates, and typical examples include alkylsulfates, polyoxyethylenalkylethersulfates, N-acylamino acid salts, N- salts acylmethyltaurine, polyoxyethylenalkyletheracetates, alkylphosphates and polyoxyethylenalkyletherherphosphates. Examples of the water-soluble polymers include polyacrylic acid, acrylic copolymers and maleic resins. Typical examples of water-soluble polymers include the water-soluble salts of resins such as an acrylic resin, a styrene-acrylic resin and a styrene-maleic resin. Typical examples of the alkali metals for salt formation are sodium and potassium Examples of the amine include primary, secondary and tertiary aliphatic amines, such as mono-, di and triethylamines; alcoholamines, such as mono, di and tripropanolamines, methylethanolamine, methylpropanolamine and dimethylethanolamine; ammonia, morpholine and N-methylmorpholine. The proportion of the dispersant & mix is 0.1 & 10% in

  weight relative to the weight of the composition.

  There is no particular limitation on the proportion of water to be used in the composition of the present invention, but suitably it is 40 & 90% by weight relative to the

weight of the composition.

  In addition, if necessary, a lubricant can be mixed, such as potassium linoleate or sodium ricinoleate, potassium oleate or sodium oleate; an antiseptic agent, such as phenol or sodium benzoate; an anti-rust agent, such as benzotriazole, dicyclohexylammonium nitrite or diisopropylammonium nitrite; and a p H adjusting agent, such as triethanolamine, monoethanolamine, diethanolamine or ammonia. The ink composition of the present invention has excellent lubricating properties and makes it possible to improve writing performance. Its functional mechanism is not clearly defined, but the following can be proposed: the oxygen atoms of the hydroxyl group and the ether bonding portion, in the structure of the adduct of the specific polyalcohol and the alkylene oxide used in the present invention, adhere to the surface of the metal, and the hydrocarbon chains are arranged on the side opposite to the metallic surface Also, the adduct itself of the specific polyalcohol and of the alkylene oxide is viscous, so that a lubricating film is formed between a ball and a ball housing, which gives properties lubricants. It can also be assumed that the ink composition of the present invention provides good lubricating properties with less smearing, due to the appropriate viscosity of the glycerin or the ethylene oxide polymer chain in the adduct. specific polyalcohol and alkylene oxide, and therefore the function of the dispersant. In addition, in the ink in which the adduct of the specific polyalcohol and of the alkylene oxide is used, the dye drools easily, but the pigment does not drool and, without the reason being apparent, it can be think this is due to

  different solubilities of the dye and pigment in the solvent.

  The pigmented aqueous ink composition for ball point pens of the present invention, when used in a ball point pen, spills very little and provides good lubricating properties, so that friction on a ball housing due to the rotation of a ball is limited So we can maintain a flow

  appropriate ink and ensure a regular writing feel.

  In addition, the ink does not dry at the tip of the ballpoint pen, so that friction is reduced. In addition, when using the pigmented aqueous ink composition of the present invention, the drying of the ink is reduced. the tip of a pen and the tip orifice can be avoided, which prevents clogging and also prevents the written characters from being blurred. Therefore, the pigmented aqueous ink composition of the present invention is

  also very desirable as an inkjet ink.

EXAMPLES

  The present invention will be described in more detail.

  by examples, without being limited to these examples.

  The inks of Examples 1 to 6 and Comparative Examples 1 to 6 were obtained by stirring and mixing the components in a stirring machine for 3 hours, dispersing the mixture with a sand mill for 5 hours, then removing the particles.

  coarse with a centrifugal separator.

  The dye inks of Comparative Examples 7 and 8 were obtained by stirring the components at a temperature of 40 to 60 WC

  for 1 hour, cooling then filtration of the mixture.

  The inks obtained in the examples and the comparative examples were evaluated according to the following writing test.

  results are shown in Table 1.

  In the writing test, we measure the penetration of the ball as well as the performance evaluation as follows

  writing and blurring of written characters.

  Penetration of the ball: After having made 500 m of writing with a writing angle of 600, a writing speed of 5.5 m / min and a load of 100 g with a helical writing tester , the depth of the worn portion of the ball housing is measured, that is to say

  the reduction in the projection of the ball relative to a support.

  Writing performance: o: Regular and stable writing performance A: Rough and difficult writing performance x: Rough and difficult writing performance and

  presence of line and direction faults.

  Blurring of written characters: o: Clear written characters without blurring c: Blurred written characters with blurring

  x: Written characters not very sharp with significant blurring.

  Example Dle 1 A black pigmented aqueous ink is prepared for pens with

  ball from the following components.

  Carbon black MA 100 l particle size 22 pm, oil absorption ml / 100 g (DBP), specific surface 134 m 2 / g (BET), manufactured by Mitsubishi Kasei Co Ltd l 8.0% p Ethyleneglycol 10.0% p Adduct of 1 mole of diglycerin and moles of ethylene oxide (viscosity 348 c P, hydroxyl number 15 mg Ko H / g) 5.0% p

  Styrene resin ammonium salt-

  acrylic acid 3.0% p Potassium linoleate 0.3% p Triethanolamine 0.5% p Phenol 0.1% p Benzotriazole 0.1% p Purified water 73.0% p Total 100.0% p Salt is prepared ammonium hydroxide by neutralization of a styrene-acrylic acid copolymer having a weight average molecular weight of 10,000, an acid number of 195, a softening point of 143 C and a glass transition temperature of

70 C, with ammonia.

  Exem Dle 2 A blue pigmented aqueous ink is prepared for pens with

  ball from the following components.

  Phthalocyanine blue (Chromofine blue 4965, manufactured by Dainichiseika Co Ltd) 8.0% p Glycerin 5.0% p Adduct of i mole of triglycerin and 20 moles of propylene oxide 10.0% p Salt d styrene-maleate resin ammonium 3.0% p Sodium ricinoleate 0.3% p Triethanolamine 0.5% p Phenol 0.1% p Benzotriazole 0.1% p Purified water 73.0% p Total 100.0 % p Comparative Example 1 The procedure of Example 1 is repeated, except that the adduct of diglycerin and 30 moles of ethylene oxide is replaced by 15% of ethylene glycol to get ink

aqueous pigmented black.

  Comparative Example 2 The procedure of Example 2 is repeated, except that the adduct of 20 moles of propylene oxide and of triglycerine is replaced by 15% of glycerine and that uses 0.5% sodium ricinoleate and 72.8% purified water to obtain an ink

blue pigmented aqueous.

  Example 3 A blue pigmented aqueous ink for ball point pens is obtained by using the following components The results of a test

  are shown in Table 1.

  Phthalocyanine blue (Chromofine blue 4965, manufactured by Dainichiseika Co Ltd) 7.0% p Ethylene glycol 17.0% p Adduct of 1 mole of glycerin and 40 moles of ethylene oxide 3.0% p Salt ammonium styrene-acrylate resin (used in Example 1) 3.0% p Potassium linoleate 0.3% p Triethanolamine 0.5% p Phenol 0.1% p Benzotriazole 0.1% p Purified water 69.0% p Total 100.0% p Exem Dle 4 A black pigmented aqueous ink for ball point pens is obtained by using the following components The results of a test

  are shown in Table 1.

  Carbon black MA 100 (manufactured by Mitsubishi Kasei Co Ltd) 8.0% p Glycerin 5.0% p Adduct of 1 mole of glycerin and moles of propylene oxide 5.0% p Ammonium salt styrene-maleate resin 3.0% p Sodium ricinoleate 0.3% p Triethanolamine 0.5% p Phenol 0.1% p Benzotriazole 0.1% p Purified water 78.0% p Total 100.0% p Comparative Example 3 The procedure of Example 3 is repeated, except that the addition product of 1 mole of glycerin and moles of ethylene oxide is replaced by 10% by weight of ethylene glycol to obtain a blue pigmented aqueous ink The results of a test

  are shown in Table 1.

  Comp Darative Example 4 The procedure of Example 4 is repeated, except that the addition product of glycerin and 10 moles of propylene oxide is replaced by 10% by weight of glycerin and that 0.5% sodium ricinoleate and 77.8% purified water are used to obtain a black pigmented aqueous ink The results of a test

  are shown in Table 1.

Example 5

  A blue pigmented aqueous ink for ball point pens is obtained by using the following components The results of a test

  are shown in Table 1.

  Phthalocyanine blue (Chromofine blue 4965, manufactured by Dainichiseika Co Ltd) 7.0% p Ethylene glycol 17.0% p Adduct of 1 mole of glycerin and moles of ethylene oxide 3.0% p Polyoxyethylene ether nonylphenyl (degree of polymerization 10) (Nicol NP-10 manufactured by Nikko Chemicals Co Ltd; having a hydrophilic-lipophilic balance of 16.5) 3.0% p Potassium linoleate 0.3% p Triethanolamine 0.5% p Phenol 0.1% p Benzotriazole 0.1% p Purified water 69.0% p Total 100.0% p

Example 6

  A red pigmented aqueous ink for ball point pens is prepared by using the following components The results of a test

  are shown in Table 1.

  Red pigment (RED K represented by the following formula, manufactured by Fuji Dyestuff Co Ltd) 8.0% p Ethylene glycol 30.0% p Ammonium salt of styrene-acrylate resin (used in Example 1) 3.0 % p potassium linoleate 0.3% p

  Adduct of 1 mole of trimethylol-

  propane and 5 moles of ethylene oxide 2.0% p Triethanolamine 0.5% p Phenol 0.1% p Benzotriazole 0.1% p Purified water 56.0% p Total 100.0% p Exemi Dle 7 A black pigmented aqueous ink for ball point pens is prepared by using the following components The results of a test

  are shown in Table 1.

  Carbon black MA 100 (manufactured by Mitsubishi Kasei Co Ltd) 8.0% p Glycerin 10.0% p Ammonium salt of a styrene-maleate resin 3.0% p Sodium ricinoleate 0.3% p Product of addition of trimethylolpropane and moles of propylene oxide 1.5% p Triethanolamine 0.5% p Phenol 0.1% p Benzotriazole 0.1% p Purified water 76.5% p Total 100.0% p Exem Comparative 5 The procedure of example 6 is repeated, except that the addition product of 1 mole of trimethylol propane and 5 moles of ethylene oxide is removed and the 58% of purified water is used to obtain a red pigmented aqueous ink. Comparative Example 6 The procedure of Example 7 is repeated, except that the addition product of i mole of trimethylol propane and 10 moles of propylene oxide is removed and the 0.5% sodium ricinoleate and 77.8% purified water are used to obtain an ink

aqueous pigmented black.

  Comparative Example 7 A black pigmented aqueous ink is obtained by using the following components The results of a writing test are shown

in table 1.

  CI Direct Black # 19 5.0% p Ethylene glycol 10.0% p Adduct of 1 mole of diglycerin and moles of ethylene oxide 5.0% p Potassium linoleate 0.3% p Triethanolamine 0, 5% p Phenol 0.1% p Benzotriazole 0.1% p Purified water 79.0% p Total 100.0% p The Direct Black # 19 mentioned above is represented by the following formula. Comparative Example 8 A blue pigmented aqueous ink is obtained by using the following components The results of a writing test are shown

in table 1.

  Blue n 1 for food (CI Acid Blue 9) Ethylene glycol Addition product of glycerin and moles of ethylene oxide Potassium linoleate Triethanolamine Phenol Benzotriazole Fluorinated anionic surfactant Purified water Purified water 6.0% p 17, 0% p 3.0% p 0.3% p 0.5% p 0.1% p 0.1% p 0.01% p 72.99% p Total 100.0% p Acid Blue 9 above is represented by the formula

next.

  The inks obtained in Examples 1 to 7 and in Comparative Examples 1 to 8 were used in ballpoint pens and a writing test was carried out with these ballpoint pens to determine the penetration of the ball, the performances writing and writing blur The test results are shown in the

table 1.

Ball penetration (Pm)

Table 1

  Blurry writing performance of written characters

Example 1

Ex comp 1

Example 2

Ex comp 2

Example 3

Ex comp 3

Example 4

Ex comp 4

Example 5

Example 6

Ex comp 5

Example 7

  Ex comp 6 Ex comp 7 Ex comp 8 o O xx As the above results show, the pigmented aqueous inks of the present invention cause considerably less penetration of the ball, ensure regular writing performance and cause less blurring. of writing. X o O O x x x o O o o 0 o x 0 o 0 o to x

Claims (8)

  1 Composition of pigmented aqueous ink for ballpoint pens, characterized in that it comprises a pigment, a dispersant, water and at least one adduct of a polyalcohol and of an alkylene oxide chosen in the group consisting of an adduct of a polyglycerin and an alkylene oxide, an adduct of glycerin and an alkylene oxide in which 1 to 150 moles of alkylene oxide are added to glycerin, an adduct of trimethylolpropane and an alkylene oxide and one of their mixtures.   2 A pigmented aqueous ink composition for ballpoint pens according to claim 1, wherein the proportion of the adduct of a polyalcohol and an alkylene oxide is in the range of 0.5 to 40% by weight , relative to the total weight of the composition.   3 A pigmented aqueous ink composition for ballpoint pens, which comprises a pigment, a dispersant, water and a   Adduct of polyglycerin and an alkylene oxide.   4 A composition of pigmented aqueous ink for ballpoint pens according to claim 3, which comprises 0.5 to 40% by weight of the adduct of a polyglycerine and an alkylene oxide in which 1 to 60 moles of the alkylene oxide are added to 2 to 4 moles of glycerin, 2 to 30% by weight of the pigment, 0.1 to 10% by weight of the dispersant and 40 to 90% by weight of water, relative to the total weight of the composition.   A pigmented aqueous pigment ink composition according to claim 4, wherein the dispersant is a polymer soluble in water.   6 A pigmented aqueous ink composition for ballpoint pens, which comprises a pigment, a dispersant, water and an adduct of glycerin and an alkylene oxide in which 1 to 150 moles of the alkylene oxide are added to the glycerin. 7. A pigmented aqueous ink composition for ballpoint pens according to claim 6, which comprises 0.5 to 40% by weight of the adduct of glycerin and alkylene oxide, 2 to 30% by weight of pigment, 0.1 to 10% by weight of the dispersant and 40 to 90% by   weight of water, relative to the total weight of the composition.   8. A pigmented aqueous ink composition for ballpoint pens according to claim 7, wherein the dispersant is a polymer. soluble in water.   9 A pigmented aqueous ink composition for ballpoint pens, which comprises an adduct of trimethylolpropane and an alkylene oxide, a pigment, a dispersant, a soluble solvent in water and water.   A pigmented aqueous ink composition for ballpoint pens according to claim 9, which comprises 0.5 to 40% by weight of an adduct of trimethylolpropane and an alkylene oxide in which 1 to 60 moles of l alkylene oxide are added to trimethylolpropane, 2 to 30% by weight of the pigment, 0.1 to 10% by weight of the dispersant and 40 to 90% by weight of water, relative to the weight total of the composition.   11 A pigmented aqueous ink composition for pens & beads according to claim 10, wherein the dispersant is a water soluble polymer.