JPH10219174A - Oil-base ink composition for ball-point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink which can give a ball-point pen free from the bleed, the formation of ink blobs and the leakage of ink and being capable of stably delivering ink from its point and capable of writing with smooth and light response of writing by selecting an ink comprising hydroxyphenylstearic acid, polyvinylpyrrolidone, fine silica particles, an organic solvent and a colorant and having a viscosity in a specified range. SOLUTION: This ink comprises a hydroxyphenylstearic acid represented by formula I (wherein x+y=14), a polyvinylpyrrolidone represented by formula II (wherein n has a value corresponding to an average molecular weight of 700,000), fine silica particles, an organic solvent and a colorant and has a viscosity of 500-5,000mPa.s at 25 deg.C. The content of the hydroxyphenylstearic acid is desirably 0.5-5.0wt.% based on the total weight of the composition. The content of the polyvinylpyrrolidone used is 0.3-0.8wt.% based on the total weight of the composition. The content of the fine silica particles used is desirably 0.01-5.0wt.% based on the total weight of the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an oil-based ink composition for a ballpoint pen.

[0002]

2. Description of the Related Art The viscosity of a conventional oil-based ink composition for a ballpoint pen is 5,000 to 20,000 mPa · s at 25 ° C.
High viscosity. The reason is that in such a high viscosity range, the change in the flow rate of the ink from the pen tip is small until the ink is used up, and the crying, the bottling phenomenon, the ejection of the ink,
This is because strikethrough (bleeding) does not occur, and the viscosity range is suitable for a ballpoint pen using oil-based ink. However, this high-viscosity oil-based ballpoint pen ink composition has a drawback that a smooth and light writing taste cannot be obtained.

On the other hand, for example, JP-A-63-309571,
JP-A-1-299880 and JP-A-8-157765 have proposed low-viscosity oil-based ink compositions for ballpoint pens whose viscosity has been reduced to 5,000 mPa · s (25 ° C.) or less. However, with this low-viscosity oil-based ballpoint pen ink composition, a smooth and light writing taste can be obtained, but a sufficient lubricating film cannot be formed between the holder and the ball, so that wear inside the holder occurs and the pen tip is stable from the pen tip. Writing is not possible due to the amount of ink spilled. Furthermore, there is a problem that the crying and the bottling phenomenon easily occur, and the ink easily leaks when the pen tip is left down.

[0004]

The problem to be solved by the present invention is to solve the above-mentioned problems, and it is possible to provide a stable ink from a pen point without crying, bottling and ink leakage. It is an object of the present invention to provide a low-viscosity oil-based ballpoint pen ink composition which has a low viscosity and maintains a high lubricity.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, it has been found that the problems can be solved by incorporating hydroxyphenylstearic acid, a specific polyvinylpyrrolidone, and particulate silica into an oil-based ink. The present invention has been completed based on the findings.

The oil-based ink composition for a ballpoint pen of the present invention has the following formula:

Embedded image A hydroxyphenylstearic acid represented by the formula

Embedded image (Here, n is a value satisfying an average molecular weight of 700,000 or more), containing polyvinylpyrrolidone, fine-particle silica, an organic solvent, and a colorant, and having a viscosity at 25 ° C of 500 to 5,000 mPa. S.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The content of hydroxyphenylstearic acid used in the oil-based ink composition of the present invention is preferably from 0.5 to 5.0% by weight based on the total amount of the composition, and if less than 0.5% by weight, the content of the present invention is reduced. When the effect of the present invention is not obtained, and when the content exceeds 5.0% by weight, the effect is not changed and is not economical. Further, other properties such as stability over time and drying property as an oil-based ink composition for a ballpoint pen are obtained. May be impaired.

[0008] The polyvinylpyrrolidone used in the oil-based ink composition of the present invention must have an average molecular weight of 700,000 or more, and its content is preferably 0.3 to 0.8% by weight based on the total amount of the composition. If the amount is less than 0.3% by weight, the effect of the present invention cannot be obtained. If the amount exceeds 0.8% by weight, a portion without ink is formed at the center of the writing line, and a phenomenon called line break occurs. This makes it difficult to obtain a beautiful writing line. Specifically, ISP
“PVP K90” (average molecular weight 1.2 million), “K120” (average molecular weight 2.8 million), “LUVISCOL K80” (average molecular weight 900,000), “LUVISCOL K90” (average molecular weight 1.2 million) manufactured by BASF And so on.

The fine-particle silica used in the oil-based ink composition of the present invention may be either a first-class product or a product whose surface has been subjected to hydrophobic treatment, as long as it has high purity and fine particles.
Specifically, "A" manufactured by Nippon Aerosil Co., Ltd.
EROSIL50 ”,“ 200 ”,“ 300 ”,
"380" and hydrophobic silica "AEROSILR20"
R972, R974, etc. The content of the fine particle silica of the present invention is preferably 0.01 to 5.0% by weight, more preferably 0.05% by weight, based on the total amount of the composition. １．０1.0% by weight, this amount being 0.0
If the amount is less than 1% by weight, the effect of the present invention cannot be obtained. If the amount exceeds 5.0% by weight, the effect of imparting thixotropy to the ink by the fine particle silica becomes too large, and sufficient ink fluidity cannot be obtained. Inconvenience occurs.

As the colorant used in the oil-based ink composition of the present invention, known dyes and pigments used in conventional ballpoint pen inks can be used. For example, as oil-soluble dyes, dyes soluble in the organic solvent used, such as Balifast Color (Orient Chemical Industry Co., Ltd.)
, Registered trademark), Aizen spiron dye, Aizen S
OT dyes (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) and the like. As the pigment, titanium oxide, carbon black, inorganic pigments such as metal powder, or azo lake, insoluble azo pigment, chelate azo pigment, phthalocyanine pigment, perylene and perylene pigment, anthraquinone pigment, quinacridone pigment, dye lake, nitro pigment,
Organic pigments such as nitroso pigments are exemplified. These colorants may be used alone or in combination of two or more, or a dye and a pigment may be used in combination. Its content is from 10 to 7 with respect to the total weight of the ink composition.
It is preferably in the range of 0% by weight.

The organic solvent used in the oil-based ink composition of the present invention is a solvent used in ordinary oil-based inks for ballpoint pens, that is, a solvent which dissolves or disperses the above-mentioned colorant and has a relatively high boiling point. Is done. Such substances include, for example, benzyl alcohol, phenoxyethanol, carbitols, cellosolves and the like. These may be used alone or as a mixture of two or more, and the content thereof is 20% based on the total amount of the composition.
Preferably it is in the range of 70% by weight.

In the ink composition of the present invention, in addition to the above essential components, other additives used in ordinary oil-based inks for ballpoint pens, for example, resins for adding viscosity, fatty acids, surfactants, rust preventives Agents, antioxidants, lubricating oils and the like can be included as necessary.

[0013]

The ball-point pen using the oil-based ink composition of the present invention has a smooth and light writing feel and has little wear on the holder, so that writing can be continued with a stable outflow of the ink, so High performance without leakage is obtained. The reason is that by setting the viscosity of the ink to a viscosity range of 500 to 5,000 mPa · s which does not cause bleeding, a smooth and light writing taste is realized, and at the same time, hydroxyphenylstearic acid is adsorbed on the surface of the ball and holder. Improves lubricity and has an average molecular weight of 7
It is considered that the spinning property is given to the ink by the polyvinylpyrrolidone resin of 100,000 or more, so that the crying and the bottling phenomenon are reduced, and the flow characteristics of the ink are changed by the fine particle silica, thereby preventing the ink leakage.

[0014]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. The ink compositions obtained in Examples and Comparative Examples were tested by the following methods. The ballpoint pen used in the test had a polypropylene tube and a stainless steel tip (the ball was made of cemented carbide tungsten carbide and had a diameter of 0.7 mm, but only the ink leak test was 1.2 mm).

A. Ink viscosity: Equipment used: EHD type viscometer (cone plate type) Tokimec (or equivalent digital viscometer DV)
Rotor used: Standard cone (1 ° 34 ') Measurement rotation speed: 5 or 10 rpm

B. Flow rate change: Writing is performed under the conditions specified in JIS S 6039 (medium shin for ballpoint pen) until the ink runs out, the weight of the test ballpoint pen is measured every 100 m of writing, and the difference from the weight (g) before the test is determined. Find the ink flow rate. Further, the difference between the ink flow rate required for writing for the first 100 m and the ink flow rate for 100 m immediately before the ink runs out was defined as a flow rate change. The average value of the test of five ballpoint pens was adopted as data.

C. Prevention of crying and crying: a) Prevention of crying After writing 100 m in a writing test, the ink adhering to the tip of the chip was rubbed on coated paper and spread with a spatula to determine the area of crying. The amount was evaluated according to the following criteria. ◎: Very small or less ○: Small △: Medium ▲: Large ×: Greater than or equal b) Prevention of dents The number of dents per 100m in the writing test is counted, and the average value of the test of five ballpoint pens is used as data. Was evaluated. ◎: No burrs ○: Less than 2 △: 2 or more to less than 5 ▲: 5 or more to less than 10 ×: 10 or more

D. Writing taste: a) Sensory evaluation by freehand writing Written on paper freehand and judge smoothness and lightness of writing feeling. ◎: Very smooth and light writing taste ○: Smooth and light writing taste △: Slightly smooth and light writing lacking ▲: Slightly heavy writing taste ×: Very heavy writing taste b) Evaluation by comparison of coefficient of friction Using a surface property measuring device, the frictional resistance when writing on writing paper with a ballpoint pen was measured, and the friction coefficient was calculated. The smaller the coefficient of friction, the lighter and smoother the writing.

E. Ink Leakage Prevention: Free-hand test ballpoint pen was left down for 7 days in a room at constant temperature and humidity (25 ° C, 60%) with the tip facing down so that the tip did not come in contact with it. Is measured and 10
The most frequent value of the test ballpoint pens was adopted as data, and the judgment was made based on the following criteria. ◎: No ink leakage at all ○: Very small amount of ink leakage at pen tip △: Medium ink leakage at pen tip ▲: Large amount of ink leakage at pen tip ×: Ink leakage fell

Example 1 The following amounts were charged into a vessel equipped with a reflux condenser and a stirrer, and stirred at 60 ° C. for 10 hours.
Excluding insolubles by pressure filtration, viscosity 3,500 mPa.
s black oil-based ink composition for a ballpoint pen was prepared. Dyeing agent (Varifast Black 1802) * 1 22 parts by weight 〃 (Varifast Yellow 1105) * 16 〃 〃 (Spiron Violet CRH) * 216 Solvent Benzyl alcohol 11.0〃 Phenoxyethanol 40.0〃 Tree Fatty polyvinyl pyrrolidone (average molecular weight 1.2 million) (PVP K90) * 4 0.5 Hydroxyphenylstearic acid 4４ Fine particle silica (Aerosil 380) * 5 0.5〃

Example 2 A black oil-based ink composition for a ballpoint pen having a viscosity of 2,700 mPa · s was prepared in the same manner as in Example 1 with the following composition. Dye (Nigrosine EX) * 1 15 parts by weight 〃 (Varifast Violet 1701) * 1 20 〃 Solvent Benzyl alcohol 22.4 〃 〃 Phenoxyethanol 32 潤 Lubricant Oleic acid 2 樹 Resin Ketone resin (Hilac 111) * 34 〃 ポ リ ビ ニ ル Polyvinylpyrrolidone (average molecular weight 1.2 million) (Rubiscol K90) * 6 0.6 ヒ ド ロ キ シ Hydroxyphenylstearic acid 3 微粒子 Fine-particle silica (Aerosil 300) * 5 1 〃

Example 3 A black oil-based ink composition for a ballpoint pen having a viscosity of 1,200 mPa · s was prepared in the same manner as in Example 1 with the following composition. Stain (Spiron Black GMH Special) * 2 15 parts by weight 〃 (Spiron Violet C-RH) * 2 15 〃 〃 (Spiron Yellow C-2GH) * 26 〃 Solvent Phenoxyethanol 58 樹 Resin Polyvinyl pyrrolidone ( (Average molecular weight 1.2 million) (PVP K90) * 4 0.5 {Hydroxyphenylstearic acid 5} Fine particle silica (Aerosil 50) * 5 0.5%

Example 4 A blue ink for oil-based ballpoint pens having a viscosity of 5,000 mPa · s was prepared in the same manner as in Example 1 with the following composition. Dyeing agent (Varifast Blue 1603) * 1 15 parts by weight 〃 (Savinyl Blue GLS) * 7 15 〃 Solvent Benzyl alcohol 5 〃 〃 Phenoxyethanol 57.2 〃 Resin Polyvinylpyrrolidone (average molecular weight 40,000) (Rubiscol K30) * 6 3 〃 ピ ロ Polyvinylpyrrolidone (average molecular weight 900,000) (Rubiscol K80) * 6 0.8 〃 Hydroxyphenylstearic acid 3 微粒子 Fine-particle silica (Aerosil 200) * 5 1 〃

Example 5 A red ink for oil-based ballpoint pens having a viscosity of 600 mPa · s was prepared in the same manner as in Example 1 with the following composition. Dye (Spiron Red C-GH) * 2 5 parts by weight 〃 (Spiron Red C-BH) * 25 〃 〃 (SPT Orange 6) * 2 15 〃 Solvent Phenoxyethanol 69 〃 Resin Polyvinylpyrrolidone (average molecular weight 2.8 million) ( PVP K120) * 4 0.7 {Hydroxyphenylstearic acid 5.0} Fine particle silica (Aerosil R974) * 5 0.3

Comparative Example 1 A black oil-based ink for a ballpoint pen having a viscosity of 2,000 mPa · s was prepared in the same manner as in Example 1 with the following composition. Dyeing agent (Varifast Black 1802) * 1 22 parts by weight 〃 (Varifast Yellow 1105) * 17 〃 ス ピ (Spiron Violet CRH) * 2 17 溶 Solvent Benzyl alcohol 12 〃 Phenoxyethanol 41.9 〃 Resin polyvinyl Pyrrolidone (average molecular weight 1.2 million) (PVP K90) * 4 0.1

Comparative Example 2 A blue oil-based ink for a ballpoint pen having a viscosity of 3,000 mPa · s was prepared in the same manner as in Example 1 with the following composition. Dyeing agent (Varifast Blue 1603) * 1 15 parts by weight 〃 (Savinyl Blue GLS) * 7 15 溶 Solvent Benzyl alcohol 4 〃 〃 Phenoxyethanol 60 〃 Resin Polyvinyl pyrrolidone (Average molecular weight 40,000) (Rubiscol K30) * 6 6 〃

Comparative Example 3 A red oil-based ink for a ball-point pen having a viscosity of 1,000 mPa · s was prepared in the same manner as in Example 1 with the following composition. Dye (Spiron Red C-GH) * 2 5 parts by weight 〃 (Spiron Red C-BH) * 25 〃 Ｓ (SPT Orange 6) * 2 15 〃 Solvent Phenoxyethanol 70.8 〃 Resin Ketone resin (Hilac 111) * 3 4 ピ ロ ポ リ ビ ニ ル Polyvinyl pyrrolidone (average molecular weight 2.8 million) (PVP K120) * 4 0.2 〃

Comparative Example 4 A black oil-based ink for ballpoint pens having a viscosity of 2,600 mPa · s was prepared in the same manner as in Example 1 with the following composition. Dye (Nigrosine EX) * 1 15 parts by weight 〃 (Varifast Violet 1701) * 1 20 溶 Solvent Benzyl alcohol 22.4 〃 〃 Phenoxyethanol 32 潤 Lubricant Oleic acid 5 樹 Resin Ketone resin (Hilac 111) * 34 〃 ポ リ ビ ニ ル Polyvinylpyrrolidone (average molecular weight 1.2 million) (Rubiscol K90) * 6 0.6 微粒子 Fine-particle silica (Aerosil 300) * 5 1 〃

Comparative Example 5 A black oil-based ink for a ballpoint pen having a viscosity of 1,500 mPa · s was prepared in the same manner as in Example 1 with the following composition. Dye (Spiron Black GMH Special) * 2 15 parts by weight {(Spiron Violet C-RH) * 2 15} {(Spiron Yellow C-2GH) * 26} Solvent Phenoxyethanol 58.5 Resin Polyvinyl Pyrrolidone (average molecular weight 1.2 million) (PVP K90) * 4 0.5 {hydroxyphenylstearic acid 5}

Comparative Example 6 A black oil-based ink for a ballpoint pen having a viscosity of 3,000 mPa · s was prepared in the same manner as in Example 1 with the following composition. Dye (Varifast Black 1802) * 1 22 parts by weight 〃 (Varifast Yellow 1105) * 16 〃 〃 (Spiron Violet CRH) * 2 10 〃 Solvent Benzyl alcohol 11 〃 Phenoxyethanol 40.5 ヒ ド ロ キ シ Hydroxyphenyl stearin Acid 4 微粒子 Fine particle silica (Aerosil 380) * 5 0.5 〃

Comparative Example 7 A black oil-based ink for a ballpoint pen having a viscosity of 14,000 mPa · s was prepared in the same manner as in Example 1 with the following composition. Dye (Spiron Black GMH Special) * 2 15 parts by weight {(Spiron Violet C-RH) * 2 15} {(Spiron Yellow C-2GH) * 26} Solvent Phenoxyethanol 45.0 Resin Ketone Resin (Hilac 111) * 3 13.0 {} Polyvinylpyrrolidone (average molecular weight 1.2 million) (PVP K90) * 4 0.5 {Hydroxyphenylstearic acid 5} Fine particle silica (Aerosil 50) * 5 0.5}

Note: * 1 [manufactured by Orient Chemical Industry Co., Ltd.] * 2 [manufactured by Hodogaya Chemical Industry Co., Ltd.] * 3 [manufactured by Hitachi Chemical Co., Ltd.] * 4 [manufactured by ISP] * 5 [Nippon Aerosil ( * 6 [BASF] * 7 [SANDOZ]

The results of the above Examples and Comparative Examples are shown in Table 1 below.
Shown in

[Table 1]

[0034]

The ballpoint pen using the oil-based ballpoint pen ink composition of the present invention can continue writing with a smooth and light writing taste and a stable ink flow rate, and has excellent performance without crying, bottling and ink leakage. Have.

Claims (1)

[Claims] (1) Formula (1) A hydroxyphenylstearic acid represented by the formula: (Here, n is a value satisfying an average molecular weight of 700,000 or more), containing polyvinylpyrrolidone, fine-particle silica, an organic solvent, and a colorant, and having a viscosity at 25 ° C of 500 to 5,000 mPa. -An oil-based ink composition for a ballpoint pen that is s.