JP2002038069A - Water base pigmented ink composition for ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water base pigmented ink composition for ballpoint pens which composition is excellent in the long-term stability and lubricating property, gives no wear of the ball seat for a metal tip, keeps an equal ink outflow during the writing, has both a uniform written-line density and a long writable distance, and also has no run of the ink and no ink leakage from the point of the metal tip, and besides has an effect on the control of the corrosion of the metal tip and an extremely good feeling on the writing touch. SOLUTION: The water base pigmented ink composition for ballpoint pens, containing a pigment, a water soluble resin and a water soluble solvent, is characterized by containing a nonionic fluorine-containing surfactant as the main component, a phosphate of a polyoxyethylene alkyl ether, and a fatty acid ester of a polyglycerine or a fatty acid ester of a polyoxyethylene sorbitane, by having the surface tension in the range of 25-30 dyn/cm, and by adjusting the pH value thereof so as be 7.5-9.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous ballpoint pen ink using a pigment as a colorant.

[0002]

2. Description of the Related Art A conventional ballpoint pen having a metal tip as a brush end is composed of a dye, a resin, benzyl alcohol as a solvent,
Those using an oil-based ink composition comprising phenyl glycol, oleic acid, etc., and those using an aqueous ink composition comprising a dye and an aqueous medium (JP-A-56-0992)
No. 69, and Japanese Patent Application Laid-Open No. 58-125770), but they are inferior in light resistance and water resistance because a dye is used as a coloring agent. Therefore, an aqueous pigment ink composition using a pigment as a colorant has been proposed.
However, since the pigment used as a colorant is insoluble in water and a solvent, the water-based pigment ink can be formed into fine particles and dispersed stably for a long time. A good writing feel cannot be obtained unless the material has excellent stability and lubricity.

[0003] In order to solve the above-mentioned problems, for example, it is composed of a pigment, a resin, and water and has a viscosity of 50 to 2000 cps.
Inks containing metal salts and / or amine salts of N-acylsarcosine (see JP-A-62-27479), and inks containing polyether polyols having primary or secondary hydroxyl groups at molecular terminals ( JP 6
JP-A-2-127372), pigments, water, those containing a water-soluble polysaccharide and a polyglycerin fatty acid ester (see JP-A-2-38474), pigments, dispersants, water-soluble solvents, water and organic phosphoric acid Ink containing an ester (see JP-A-62-000568), a colorant, a solvent, and water, and containing an alkali metal salt and / or an amine salt of N-acylmethyltauric acid (see JP-A-4-000568). 1
No. 64977) has been proposed, but problems such as a large bleeding of the writing line and aggregation of the pigment occur, so that a sufficient lubricating effect cannot be obtained and as the writing proceeds, The ball seat is worn and the writing feel is deteriorated, and the writing lines are blurred, broken, and braille. The writing state is extremely poor, and the above problem of obtaining a good writing feel has not been sufficiently solved.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the conventional pigment ink for water-based ball pens, to provide excellent long-term stability and lubricity, and to provide a ball seat for metal chips. No ink abrasion, maintain uniform ink outflow during writing, uniform writing line density, long writing distance, no ink bleed, no tip leakage from the metal tip,
It is still another object of the present invention to provide a pigment ink composition for an aqueous ball-point pen having extremely good writing feel without corrosion of metal chips.

[0005]

As a result of various studies to solve the problems described above, the present invention provides a pigment ink composition for water-based ball pens containing a pigment, a water-soluble resin and a water-soluble solvent. It contains a nonionic fluorine-containing surfactant, a polyoxyethylene alkyl ether phosphate and a polyglycerol fatty acid ester or a polyoxyethylene sorbitan fatty acid ester having an HLB of 10 or more as essential components, and has a surface tension of 25 to 30 dym /
It has been found that the object can be achieved by adjusting the pH value to fall within the range of 7.5 to 9.0 and the pH value to 7.5 to 9.0, thereby completing the present invention.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The nonionic fluorine-containing surfactant used in the present invention is added to adjust the surface tension of this pigment ink composition for aqueous ballpoint pens to a range of 25 to 30 dyn / cm. Among them, among the nonionic fluorine-containing surfactants, those represented by the following general formula (1), particularly those having a value of n of 10 to 20 are effective. The pigment ink composition for a water-based ballpoint pen of the present invention can be used in the range of 0.01 to 0.1% by weight based on the total amount. If the amount is less than 0.01% by weight, the surface tension of the ink composition becomes 30 dyn / cm or more, and the lubricating effect cannot be obtained. If it exceeds 0.1% by weight, the surface tension becomes 25 dyn / cm or less, and although there is a lubricating effect, the ink naturally leaks from the tip of the metal chip, so-called pre-leakage occurs, and bleeding increases. There are drawbacks.

[0007]

Embedded image

The polyoxyethylene alkyl ether phosphate and the polyglycerin fatty acid ester or polyoxyethylene sorbitan fatty acid ester having an HLB of 10 or more are formed by dissociating ions and the fatty acid ester interacting with each other, that is, the inner surface of the metal chip, It is believed that the writing feel is improved because a layer is formed between the ball and the ball seat. A disadvantage that could not be solved by adding only polyoxyethylene alkyl ether phosphate or a polyglycerin fatty acid ester or a polyoxyethylene sorbitan fatty acid ester having an HLB of 10 or more, that is, excellent long-term stability and a good writing feel. The problem was solved by using a nonionic fluorine-containing surfactant, a polyoxyethylene alkyl ether phosphate and a polyglycerin fatty acid ester or a polyoxyethylene sorbitan fatty acid ester having an HLB of 10 or more.

The amount of the polyoxyethylene alkyl ether phosphate can be used in the range of 0.5 to 3.0% by weight based on the total amount of the aqueous pigment ink composition for ballpoint pens of the present invention. The amount of polyglycerin fatty acid ester or polyoxyethylene sorbitan fatty acid ester having an HLB of 10 or more can be added in the range of 0.2 to 1.0% by weight based on the total amount of the aqueous pigment ink composition for ballpoint pens of the present invention. When a polyoxyethylene alkyl ether phosphate is added and a polyglycerin fatty acid ester or a polyoxyethylene sorbitan fatty acid ester having an HLB of 10 or more is not added, or a polyglycerin fatty acid ester or a polyoxyethylene sorbitan fatty acid ester having an HLB of 10 or more is added. In the case where the oxyethylene alkyl ether phosphate is not added, if the ball pen filled with the ink composition is continuously used, the ball receptacle at the end of the pen is worn down, so that the amount of ink gradually discharged is reduced. In addition, the writing feel becomes poor, causing blurring and broken characters. When a polyglycerin fatty acid ester or a polyoxyethylene sorbitan fatty acid ester having an HLB of less than 10 is added, sufficient interaction is not obtained due to insufficient dissociation of ions, and the pen at the tip of the pen tip of a ballpoint pen is not obtained.
Since the receiving seat is worn away, the amount of ink gradually decreases, the writing feel deteriorates, and blurring and broken characters occur. The total addition amount of the polyoxyethylene alkyl ether phosphate and the polyglycerin fatty acid ester or polyoxyethylene sorbitan fatty acid ester having an HLB of 10 or more is 0.
If the amount is less than 7% by weight, the formation of the layer is insufficient, so that the writing feel is insufficiently improved. If the amount is more than 4.0% by weight, the writing feeling is improved, but a leak occurs. Would. The preferred total amount is in the range of 0.7 to 4.0% by weight based on the total amount of the pigment ink composition for water-based ballpoint pens of the present invention. Is from 2: 1 to 4: 1 depending on the material.

The polyoxyethylene alkyl ether phosphates include those described in P.S. O. E (10) sodium lauryl ether phosphate; O. E (4) sodium lauryl ether phosphate; O. E (5) sodium cetyl ether phosphate; O. E (8) sodium oleyl ether phosphate and the like. Polyglycerin fatty acid esters and polyoxyethylene sorbitan fatty acid esters having an HLB of 10 or more include hexaglyceryl monomyristate, decaglyceryl monolaurate, decaglyceryl monostearate, decaglyceryl monooleate, decaglyceryl monolinoleate, and monopalmitin. Acid P. O. E (20) sorbitan, monostearic acid P.E. O. E (20) sorbitan, monooleic acid O. E (20) sorbitan, trioleic acid
O. E (20) sorbitan, monooleic acid O. E
(6) Sorbitan can be exemplified.

[0011]

The mechanism by which a good writing feel is obtained is not clear, but the ion generated by the dissociation of the polyoxyethylene alkyl ether phosphate and the polyglycerol fatty acid ester or polyoxyethylene sorbitan fatty acid ester having an HLB of 10 or more are formed. Adsorbs while interacting with each other, creating a better lubrication effect on the inner surface of metal chips, balls and pigment particles, and combining micelles of anions generated by the dissociation and nonionic fluorine-containing surfactants. Synergistic lubrication that cannot be obtained by simply adding a nonionic fluorine-containing surfactant, a polyoxyethylene alkyl ether phosphate and a polyglycerin fatty acid ester or a polyoxyethylene sorbitan fatty acid ester having an HLB of 10 or more. Make effect Because the believed to better writing feel is obtained. When a cationic surfactant is used as the fluorine-containing surfactant, a synergistic lubricating effect cannot be obtained due to a charge canceling action. On the other hand, in the case of the anionic system, the charged ions become too large, and the osmotic pressure effect required for dispersion expected to achieve the object of the present invention cannot be obtained, causing separation of the ink composition. Therefore, the fluorine-containing surfactant needs to be nonionic as shown in the present invention.

The pH of the ink composition is adjusted in order to suppress the rust of the metal chips, stabilize the water-soluble resin used, and secure the above-mentioned interaction. As a pH adjuster,
There are triethanolamine, N-methyldiethanolamine, diisopropanolamine, monoethanolamine, triethylamine, and the like, and the amount used is such that the pH value of the ink composition is in the range of 7.5 to 9.0. When the pH value of the ink composition is less than 7.5, the writing feel and the state of the writing line are deteriorated depending on the material of the metal tip used for the ballpoint pen to be filled with the aqueous ballpoint pen ink composition of the present invention. In severe cases, rust is generated within a short period of time, and the ink inside the chip is agglomerated. When the pH value is 9.0 or more, the long-term stability of the ink becomes poor.

The pigment used in the pigment ink composition for water-based ball-point pens of the present invention is not particularly limited, and any one of inorganic and organic pigments used in ordinary pigment ink compositions for water-based ball-point pens can be used. can do. The amount used is 5 to 30% by weight, preferably 8 to 30% by weight, based on the total amount of the pigment ink composition for aqueous ballpoint pens of the present invention.
It is selected in the range of 20% by weight.

Examples of the water-soluble resin include a water-soluble acrylic resin, a crosslinked acrylic resin, carboxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, poly-N-vinylacetamide, methylcellulose, carboxycellulose, hydroxymethylcellulose, ethylcellulose, hydroxyethylcellulose, and hydroxyethylcellulose. Examples include propylcellulose, sodium alginate, and a copolymer of vinyl acetate and polyvinylpyrrolidone. These water-soluble resins can be used alone or as a mixture of two or more, and are contained in the range of 0.1 to 0.4% by weight based on the total amount of the aqueous pigment ink composition for ballpoint pens of the present invention. If the content is less than 0.1% by weight, a viscosity suitable for writing cannot be obtained, and if it exceeds 0.4% by weight, the viscosity of the ink composition becomes too high, so that the outflow amount at the time of writing is small. Lines are blurred or Braille occurs, the writing feel is heavy, and the writing performance deteriorates.

As the water-soluble solvent, one or a mixture of two or more of propylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, glycerin, polyethylene glycol and the like can be used.
Usually, it is used in the range of 10 to 40% by weight.

Further, in addition to the above main components, commonly used pigment dispersants, rust preventives, preservatives, wetting agents and the like can be added and used. Examples of the pigment dispersant include acrylic / styrene copolymers, maleic acid / styrene copolymers, and neutralized salts thereof, and examples of the rust preventive include benzotriazole, tolyltriazole, and dicyclohexylammonium nitrate. Can be illustrated.
Examples of preservatives include sodium benzoate, potassium sorbate, sodium pentachlorophenol, and the like.
As the wetting agent, a hygroscopic substance such as urea or a urea derivative can be used.

[0017]

Next, the present invention will be described in detail with reference to examples. As examples of the aqueous pigment ink composition for ballpoint pens of the present invention, those having the compositions shown in Table 1 below were prepared.

[0018]

[Table 1]

In Examples 1 to 7 shown in Table 1, a water-soluble resin such as ethylene glycol and glycerin and water were mixed with a water-soluble resin such as a crosslinked acrylic resin, polyvinylpyrrolidone, and poly-N-vinylacetamide. Add with vigorous stirring to dissolve completely. Next, a pigment and an acrylic / styrene copolymer as a pigment dispersant were added to uniformly disperse the pigment. O. E (8) sodium oleyl ether phosphate, decaglyceryl monooleate, monooleic acid P.E. O. E (6) sorbitan, monooleic acid O. E (10) Sorbitan and a nonionic fluorine-containing surfactant are added. Add urea and benzotriazole additives and keep stirring vigorously. Finally, the pH value was adjusted to 7.5 to 9.0 by adding triethylamine or triethanolamine, and this was used as a pigment ink composition for an aqueous ballpoint pen.

The physical properties of Examples 1 to 7 are shown in Table 2 below.

[0021]

[Table 2]

Next, as comparative examples, those having compositions shown in Table 3 below were prepared.

[0023]

[Table 3]

Comparative Example 1 is an ink composition prepared from Example 1 except that EF-122A which is a nonionic fluorine-containing surfactant was removed. Comparative Example 2 is an ink composition prepared by removing the polyoxyethylene alkyl ether phosphate, DOP-8N, from the composition of Example 2. Comparative Example 3 is based on the composition of Example 3 except that TO-10 which is a polyoxyethylene sorbitan fatty acid ester is used.
This is an ink composition adjusted except for No. 6. Comparative Example 4
From the composition of Example 4, P was added without adding triethanolamine.
This is an ink composition in which H adjustment is not performed. Comparative Example 5
Polyglycerol fatty acid ester D of the composition of Example 4
This is an ink composition prepared using DGMO-C having an HLB of 5.5 instead of ecaglyn 1-0.

The physical properties of Comparative Examples 1 to 5 are shown in Table 4 below.

[0026]

[Table 4]

The pigment ink compositions for water-based ballpoint pens prepared as Examples 1 to 7 and Comparative Examples 1 to 5 were treated with an inner diameter of 3.5.
Approximately 10c in height in a polyethylene pipe
m, about 0.8 g in weight, filled with a stainless steel tip for water-based ballpoint pen, and filled with grease in the back of the ink to prevent drying and outflow of the ink. A test core used for the following test was obtained by removing air remaining between the inks.

Writing Feeling: The writing feeling when five testers handwritten the test core was evaluated. The evaluation was as follows: ◎: 4 or more out of 5 persons had good writing feeling. : Three out of five persons felt that the writing feeling was good. Δ: One or two of the five persons had good writing feel. X: One out of five persons did not consider that the writing feeling was good. In four stages.

Bleedability: Written by hand on a writing paper, and the evaluation was made based on the line width of the image and the presence or absence of bleed at that time. The evaluation was as follows: ◎: No bleeding was observed. : Somewhat blurred but not noticeable. ×: Bleeding is observed and the line width is increased. In three stages.

Long-term stability: A test core was placed in a glass container and stored in a thermostatic chamber set at a temperature of 50 ° C. and a relative humidity of 60%. After 6 months, the viscosity and pH value of the ink composition were measured. Measured and watched the change. The evaluation was as follows: ◎: A change in viscosity was within ± 20%, and a change in pH value was negligible or very slight. ：: The change in viscosity is ± 20 to 50% and the change in pH value is less than 1. X: The change in viscosity is ± 50% or more, or the ink gels or separates, or the change in pH value is 1 or more. In three stages.

Lubricity: A test core was written at room temperature at a writing angle of 70 °, a writing speed of 4 m / min, and a writing load of 100 g, and the ink consumption was measured every 100 m of writing distance. In addition, the degree of wear of the ball seat of the stainless steel tip for the water-based ballpoint pen attached to the test core was observed. The evaluation was as follows: ◎: No wear on the ball seat and no significant difference in the ink consumption value at every 100 m writing distance. ：: The ink consumption increased as the ball seat was slightly worn and the writing distance was increased. Δ: Abrasion of the ball seat was large, the ink inlet hole was blocked, and the ink consumption gradually decreased, resulting in a poor writing line condition. X: The ink consumption was remarkably reduced, and 80 mg / 100
What has become m. In four stages.

Leakage: The pen tip of the test core was fixed vertically downward, and it was observed whether the ink spontaneously leaked from the pen tip. The evaluation was as follows: ◎: No leakage occurred. : Slightly leaked but not so noticeable. ×: Leakage caused trouble in writing. In three stages.

Chip corrosion: The test core was heated at a temperature of 50 ° C.
The sample was stored in a thermostatic chamber set to a relative humidity of 60%, and after 6 months, the corrosion state in the chip was observed using a microscope.
The evaluation was as follows: A: No corrosion was observed. : The inside of the chip was slightly discolored due to corrosion. ×: Discoloration significantly due to corrosion. In three stages.

Table 5 shows the results of the above six tests.

[0035]

[Table 5]

[0036]

As described in detail above, the effect is obtained in a pigment ink composition for an aqueous ballpoint pen containing a pigment, a water-soluble resin and a water-soluble solvent, as a nonionic fluorine-containing surfactant and polyoxyethylene as essential components. By containing an alkyl ether phosphate and a polyglycerin fatty acid ester or a polyoxyethylene sorbitan fatty acid ester, a nonionic fluorine-containing surfactant,
Polyoxyethylene alkyl ether phosphate, polyglycerin fatty acid ester or polyoxyethylene sorbitan fatty acid ester exerts a synergistic lubricating effect that cannot be obtained by simply adding each alone, and the writing feel is extremely good. Further, the surface tension is 25 to 30 dyn
/ Cm, the pH value of the ink composition is adjusted to be in the range of 7.5 to 9.0, so that the ink composition has excellent long-term stability, has no ink bleeding, and has a tip from the tip of the metal tip. A pigment ink composition for water-based ballpoint pens that has no leakage and has an effect of suppressing corrosion of metal chips.

Claims (2)

[Claims] 1. An aqueous ballpoint pen ink composition containing a pigment, a water-soluble resin and a water-soluble solvent, wherein a nonionic fluorine-containing surfactant, a polyoxyethylene alkyl ether phosphate and a polyglycerin fatty acid ester are essential components. Or containing polyoxyethylene sorbitan fatty acid ester and having a surface tension of 25 to 30 dy.
A pigment ink composition for an aqueous ballpoint pen, wherein the pH is in the range of n / cm and the pH is adjusted to 7.5 to 9.0. 2. HLB (Hy) of polyglycerin fatty acid ester or polyoxyethylene sorbitan fatty acid ester.
drophile-Lipofile Balanc
The pigment ink composition for an aqueous ball-point pen according to claim 1, wherein the value of e) is 10 or more.