JPH0811480A - Ink reservoir for liquid low viscosity ink writing instruments - Google Patents

Abstract

(57) [Summary] [Structure] The ink reservoir is made of polypropylene, polyethylene, polyvinyl chloride, styrene / butadiene copolymer, ethylene / butylene / styrene block copolymer,
Acrylic / butadiene / styrene copolymer, ethylene /
A thermoplastic elastomer resin such as a vinyl acetate copolymer is mixed with 0.01% of a surfactant containing a polymer of an alkyl ester of acrylic acid or methacrylic acid whose hydrophilic portion is a carboxylic acid group or a sulfonic acid group. By adding ~ 1% and molding, the surface of the ink storage part becomes a hydrophilic surface, and by improving the wetting of the ink, it is possible to prevent insufficient supply of ink to the writing end of the liquid low viscosity writing instrument when writing. . [Effect] The fluidity of the ink in the ink storage portion of the liquid low-viscosity writing instrument is ensured, and insufficient supply of ink to the writing edge due to poor ink flow is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a main shaft of a low viscosity ink writing instrument, and more particularly to a main shaft of a liquid type low viscosity ink writing instrument having an ink reservoir.

[0002]

2. Description of the Related Art In low-viscosity ink writing instruments, especially those of the liquid type, an ink outflow control cylinder provided between the ink storage portion and the writing end serves to supply ink to the writing end and It works to prevent ink from flowing out of the pen due to the expansion and contraction of air. Therefore, the ink used is required to have a certain degree of viscosity and surface tension. The viscosity is 2 to 10 CP at 20 ° C. and the surface tension is 2
The temperature is generally 0 to 25 to 40 dyne / cm. For this reason, when the ink storage portion is formed by using the resin that has been conventionally used, the movement of the ink in the ink storage portion is considerably deteriorated due to the influence of the surface tension of the ink itself. Therefore, in the case of using a liquid low-viscosity ink writing tool which is left with the writing end facing upward, there are cases where ink is not properly supplied to the writing end. In order to prevent such a phenomenon, it is necessary to assist the movement of the ink by providing a slit in the ink storage portion in the axial direction.

[0003]

However, in a liquid type low-viscosity ink writing instrument, the ink storage portion is often formed by using a transparent resin, and in this case, it is provided inside the ink storage portion to assist the movement of the ink. Axial slits were visible from the outside, impairing the appearance of the liquid low-viscosity writing instrument.

[0004]

SUMMARY OF THE INVENTION The present invention provides an ink reservoir that allows ink in the ink reservoir to freely flow in the ink reservoir regardless of the influence of the surface tension of the ink itself. That is, the ink storage part is treated with polypropylene, polyethylene, polyvinyl chloride, styrene / butadiene copolymer, ethylene / butylene / styrene block copolymer, acrylic, butadiene / styrene copolymer, ethylene / vinyl acetate copolymer, etc. 0.01 to 1% of a surfactant containing a polymer of an alkyl ester of acrylic acid or methacrylic acid whose hydrophilic portion is a carboxylic acid group or a sulfonic acid group as a main component in a plastic elastomer resin
It is to add and shape. The hydrophilic portion of the surfactant added in the present invention is acrylic acid, methacrylic acid, maleic acid, itaconic acid, itaconic acid monoester, maleic acid monoester, etc., and the lipophilic portion is styrene, styrene. Examples include derivatives.

[0005]

Since it has the above-mentioned constitution, the surfactant whose main component is a polymer of an alkyl ester of acrylic acid or methacrylic acid whose added aqueous portion is a carboxylic acid group or a sulfonic acid group at the time of molding is polypropylene. , Polyethylene, polyvinyl chloride, styrene / butadiene copolymer, ethylene / butylene / styrene block copolymer,
Acrylic / butadiene / styrene copolymer, ethylene /
Since it is not compatible with thermoplastic elastomer resins such as vinyl acetate copolymer, it bleeds onto the surface of the molded product at the end of molding and the wettability of the surface of the molded product is improved because the hydrophilic parts are arranged toward the outside. .

[0006]

EXAMPLES Hereinafter, examples in which the present invention is carried out with an ink guide core of a water-based ballpoint pen will be described in detail. Example-1 Diapet ABS (ABS resin, Mitsubishi Rayon Co., Ltd.) 100 parts by weight Johncryl 78 (styrene-acrylic acid copolymer, Johnson Co., Ltd.) 0.2 parts by weight Ink storage in an aqueous ballpoint pen having the above composition. The part was molded. Comparative Example-1 Diapet ABS (ABS resin, Mitsubishi Rayon Co., Ltd.) 100 parts by weight An ink reservoir of an aqueous ballpoint pen was molded with the above composition. Example-2 Diapet ABS (ABS resin, Mitsubishi Rayon Co., Ltd.) 100 parts by weight SMA1440H (styrene-maleic acid copolymer, ARCO chemicai company) 0.2 parts by weight The ink storage part of an aqueous ballpoint pen is molded with the above composition. did. Comparative Example-2 Diapet ABS (ABS resin, Mitsubishi Rayon Co., Ltd.) 100 parts by weight An ink reservoir of an aqueous ballpoint pen was molded with the above composition. Example-3 Mitsui Noblene (PP resin, Mitsui Toatsu Chemicals, Inc.) 100 parts by weight Johncryl 62 (α-methylstyrene-acrylic acid copolymer Johnson Co., Ltd.) 0.2 parts by weight Aqueous ballpoint pen having the above composition. The ink storage part was molded. Comparative Example-3 Mitsui Noblene (PP resin, Mitsui Toatsu Chemicals, Inc.) 100 parts by weight An ink reservoir of a water-based ballpoint pen was molded with the above composition. Example-4 Evaflex 420 (Mitsui / Dupont Polychemical Co., Ltd.) 100 parts by weight Johncryl 78 (Styrene-acrylic acid copolymer, Johnson Co., Ltd.) 0.2 parts by weight Ink storage in an aqueous ballpoint pen having the above composition. The part was molded. Comparative Example-4 Evaflex 420 (Mitsui DuPont Polychemical Co., Ltd.) 100 parts by weight An ink reservoir of an aqueous ballpoint pen was molded with the above composition. Example-5 Denkabinicon (PVC resin, manufactured by Denki Kagaku Kogyo Co., Ltd.) 100 parts by weight Johncryl 78 (styrene-acrylic acid copolymer, Johnson Co., Ltd. 0.2 parts by weight) Ink storage part of aqueous ball-point pen having the above composition Comparative Example-5 Denkabinicon (PVC resin, manufactured by Denki Kagaku Kogyo Co., Ltd.) 100 parts by weight An ink reservoir of an aqueous ballpoint pen was molded with the above composition.

[0007]

The ink reservoirs obtained in Examples 1-5 and Comparative Examples 1-5 were used to assemble water-based ballpoint pens,
An ink fluidity test when assembled was performed. The ink fluidity test results are shown in Table 1. Ink fluidity test 100 water-based ballpoint pens were assembled by a normal method, and the movement of the ink was observed when the writing edge was facing downward from the writing edge facing downward. Evaluation method Number of defective ink flow 0 to ○ 1 to 10 to Δ 10 or more to × As described above, the ink storage portion of the present invention shows excellent results in the ink flow test, and there is no ink flow during writing. It is effective in preventing poor ink supply to the writing edge.

Claims (1)

[Claims] 1. A liquid low-viscosity ink writing instrument comprising polypropylene, polyethylene, polyvinyl chloride, styrene / butadiene copolymer, ethylene / butylene / styrene block copolymer, acrylic / butadiene / styrene copolymer, ethylene / acetic acid. A thermoplastic elastomer resin such as a vinyl copolymer is added with a surfactant whose main component is a polymer of an acrylic acid or methacrylic acid alkyl ester polymer whose hydrophilic portion is a carboxylic acid group or a sulfonic acid group. Ink storage part of liquid type low viscosity ink writing instrument, which is characterized by adding 1% and molding.