JP3190528B2 - Synthetic resin nib - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin nib capable of obtaining a thin line drawing and satisfying writing quality and strength.

[0002]

2. Description of the Related Art Conventionally, most of the pen tips of ultra-fine felt-tip pens have been used with a small-diameter pen tip formed by melt extrusion of a synthetic resin. Usually, such a pen tip extrudes a thermoplastic resin in a molten state from a die provided with a plurality of holes arranged close to each other to form a plurality of filaments, and the surface of the filament has a fusible property. In this state, the filaments are formed by a manufacturing method in which the filaments are brought into contact with and fused with each other, and a space serving as an ink conduction path is formed in the longitudinal direction without being contacted and fused.
In recent years, those using polyacetal homopolymer and polyetheretherketone resin and having high wear resistance and mechanical strength have become mainstream. The very fine nib is
The ink is brought into contact with the paper surface by sliding on the paper surface that is the object to be written, and writing is performed.However, using a high-strength nib as described above, the higher the strength, the worse the writing taste is There are disadvantages. In addition, polyacetal copolymer is said to be excellent in writability when compared with polyacetal homopolymer because of its low mechanical strength, but its abrasion resistance is low and its dynamic friction coefficient is large, so writing is poor. Not satisfied with the taste.
Poor writing not only increases the fatigue of long-time writing, but also makes the writing itself uncomfortable and prevents the use of such writing instruments.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art, and it has high strength, high abrasion resistance, excellent writing quality, and can sufficiently cope with mass production. It provides a pen point such as a felt-tip pen.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors focused on polyacetal as a material, and mixed and molded a polyacetal homopolymer and a polyacetal copolymer at a specific ratio. As a result, the above problem was successfully solved, and the synthetic resin nib of the present invention was completed.

That is, the synthetic resin nib of the present invention comprises:
A plurality of filaments are formed by extruding a thermoplastic resin in a molten state from a die provided with a plurality of holes arranged close to each other, and the filaments are mutually bonded in a state where the surfaces of the filaments have fusibility. contact, together with the fusing, the contact, in the synthetic resin nib comprising a space of an ink capillary passage is formed in the axial direction without fusing, polyacetal homopolymer 90-75% by weight, the polyacetal copolymer 10 to 25 weight % Of synthetic resin by melt extrusion molding.

[0006] Polyacetal homopolymer is known as a melt flow rate (hereinafter referred to as MFR) JIS K-7210.
Test condition 4, test temperature 190 ° C., test load 21.18
N is preferably 0.5 to 1.5 (g / 10 min),
Polyacetal copolymers have MFR = 0.5-1.
5 (g / 10 min) is preferred. The ratio of the polyacetal copolymer is 10 to 25% based on the whole polymer,
Preferably, it is used at 15 to 20%. If the blending amount of the copolymer is less than 10%, poor writing quality of the pen tip with the homopolymer alone cannot be avoided. If the blending amount is more than 25%, the mechanical strength such as abrasion resistance decreases and the homopolymer becomes poor. The advantage of using is diminished.

[0007] The method of manufacturing the nib of the present invention includes:
Molten synthetic resin is discharged from small holes that are in close proximity to each other,
After the resin is fused together by the ballast effect, the resin is stretched to a desired size before being cooled and solidified. When forming a desired shape by stretching, a manufacturing method of discharging a resin in a downward direction is generally used to maintain a cylindrical shape without being affected by gravity. The MFR of the resin used is preferably 0.5 to 1.5 (g / 10 min). If the (MFR) of the resin is too high, not only is it not possible to form a sufficient capillary for the ink to be drawn out from the occlusion body by capillary action due to the ink inside the pen tip with the mutually fused filaments, but also to form the resin. Due to its own weight, it falls before being stretched to a predetermined size, and if it is too low, it cannot be stretched uniformly with a take-off machine, and it will be cut off one by one, making it impossible to obtain a pen tip.

[0008]

The pen tip of the present invention can improve the thermal stability when only the homopolymer is molded by containing the polyacetal copolymer and the polyacetal homopolymer in a specific ratio. Is not mixed as air bubbles, and the mechanical strength decrease due to homopolymer molecular cutting is unlikely to occur,
There is also an advantage that a pen body with stable physical properties can be supplied. The reason for the effect is that the extra-fine nib slides on the surface of the object to be written on, and the ink comes into contact with the surface of the nib, thereby writing. In addition to the coefficient, the surface of the paper has cellulose fibers running randomly in the vertical and horizontal directions, and has an uneven surface when enlarged. If the vibration generated at this time is made of only a hard material, there is no portion for damping the vibration, so that the vibration is directly transmitted to the hand holding the writing instrument, giving an unpleasant feeling of poor writing. What blended the ratio of the polyacetal copolymer with respect to the whole polymer by 10 to 25%,
Since the vibration generated at the tip of the pen core is attenuated at that portion, it is considered that the user feels good in writing without being transmitted to the hand holding the writing instrument.

[0009]

Next, the present invention will be described more specifically with reference to examples and comparative examples.

(Example 1) Polyacetal homopolymer [“Tenac 1030” manufactured by Asahi Kasei Corporation, MFR 1.
0 (g / 10 min)], 85%, polyacetal copolymer [“Tenac CBC-150” manufactured by Asahi Kasei Corporation, MFR
1.0 (g / 10 min)] 15%, and a long pen body having an outer diameter of 0.8 mm and an ink capillary passage formed in the axial direction was obtained by melt extrusion molding using a melt extrusion molding process.
After the short cut, both ends were polished into a desired shape to obtain a pen tip.

Comparative Example 1 Polyacetal homopolymer [“TENAC 1030” manufactured by Asahi Kasei Corporation, MFR 1.0
(G / 10min)] by melt extrusion molding
A long nib having an outer diameter of 0.8 mm having an ink capillary passage formed in the axial direction was obtained. After cutting the short nib, both ends were polished into a desired shape to obtain a nib.

Comparative Example 2 Polyetheretherketone resin [Victrex 450G] Mitsui Toatsu Chemicals, Inc.
MFR 0.9 g / 10 min, test temperature 360 ° C., test load 21.18 N], and an outer diameter 0.8 in which an ink capillary passage is formed in the axial direction by melt extrusion forming.
A long nib with a length of mm was obtained, and after cutting the short nib, both ends were polished into a desired shape to obtain a nib.

(Comparative Example 3) A polyacetal copolymer ("Jaracon U-10" manufactured by Polyplastics Co., Ltd., MFR 1.0 (g / 10 min)) was used and melt-extrusion-molded to form an ink in the axial direction. A long nib having an outer diameter of 0.8 mm having a capillary passage was obtained, and after cutting the short nib, both ends were polished into a desired shape to obtain a nib.

Comparative Example 4 Polyacetal Homopolymer (TENAC 1030 Asahi Kasei Corporation MFR 1.0)
g / 10min) 85%, polyacetal copolymer (TENAC C 3530, Asahi Kasei Corporation MFR 3.0 g)
/ 10 min) Using a mixture that was stirred and mixed to 15%, a long nib with an outer diameter of 0.8 mm having an ink capillary passage formed in the axial direction was obtained by melt extrusion processing, and after cutting the short length, both ends were desired. Polished to obtain a pen point.

Comparative Example 5 Polyacetal Homopolymer (TENAC 3010 Asahi Kasei Corporation MFR 3.0)
g / 10min) 85%, polyacetal copolymer (TENAC C 3530, Asahi Kasei Corporation MFR 3.0 g)
/ 10min) Using a mixture that has been stirred and mixed to 15%, obtains a long nib with an outer diameter of 0.8 mm having an ink capillary passage formed in the axial direction by melt extrusion molding. Polished to obtain a pen point.

(Comparative Example 6) Polyacetal homopolymer (TENAC 1030 Asahi Kasei Corporation MFR 1.0)
g / 10min) 70%, polyacetal copolymer (TENAC C BC-150 MFR manufactured by Asahi Kasei Corporation)
0g / 10min) 30% of the mixture was stirred and mixed, and a melt-extrusion molding process was used to obtain a long nib with an outer diameter of 0.8 mm and an ink capillary passage formed in the axial direction. The nib was polished to a desired shape to obtain a nib.

(Comparative Example 7) Polyacetal homopolymer (TENAC 1030 MFR1.0 manufactured by Asahi Kasei Corporation)
g / 10 min) 95%, polyacetal copolymer (TENAC C BC-150, MFR manufactured by Asahi Kasei Corporation)
0g / 10min) Using a mixture that had been stirred and mixed to 5%, a long nib with an outer diameter of 0.8 mm having an ink capillary passage formed in the axial direction was obtained by melt extrusion molding.
Both ends were polished to a desired shape to obtain a pen tip.

After passing the nibs obtained in Example 1 and Comparative Examples 1 to 7 through respective stainless steel pipes, the tip of the nib was exposed by 2 mm, and the tip of the pipe was fixed by caulking. Then, it was inserted into a hard polyethylene base and pressed into a shaft of a writing instrument to be fixed. Then, an ink occluding material made of polyethylene terephthalate fiber filled with an aqueous ink in which carbon black was dispersed was inserted, and a writable pen was assembled.

The performance test of the obtained nib was performed by the following method. -Writing taste The writing taste was evaluated by a sensory test of 30 skilled workers.
The writing object differs in evaluation of writing taste depending on the surface condition (for example, coated paper or the like having a smooth surface).
SP 3201 Writing paper A "was used. Each tester's example and comparative example were evaluated on a five-point scale with a perfect score of 5 and a total of 30 (5 points x 30 = 150)
(The point is the highest point), and it was judged by the score evaluation, and evaluated according to the following criteria. ◎ Very good (Score: 131 to 150 points) ○ Good (Score: 101 to 130 points) □ Normal (Score: 71 to 100 points) △ Slightly poor (Score: 41 to 70 points) × Bad (Score: 40 points) Below) ・ Bending elastic modulus A three-point bending test was performed on the pen tip alone, and the bending elastic modulus was calculated. -Writable distance, ink consumption rate Written up to 2000 m with a writing test machine, and measured the writable distance and the ink consumption rate.

Abrasion degree At the same time as the above test, a dimensional change due to abrasion of the tip from 0 m was measured, and the value of each example when Comparative Example 1 was set to 100 was calculated as the abrasion degree by the following equation.

(Equation 1)

Table 1 shows the results.

[Table 1]

As is clear from the above table, Example 1
All of them are overall better than the comparative examples, and it can be seen that the performance is very balanced.

[0023]

The pen tip of the present invention has a better writing taste than the conventional one and has the same performance as the conventional high strength and high wear resistance pen tip. The effect is great when writing on high people or paper with high surface roughness. In terms of production, it can be continuously formed by extrusion and mass production is possible, which is advantageous in cost.

Claims (2)

(57) [Claims] 1. A method of molding a plurality of filaments by extruding a thermoplastic resin in a molten state from a die having a plurality of holes arranged close to each other, and forming a plurality of filaments in a state in which the surface of the filaments has a fusible property. Contact the filaments with each other,
With fusing, contact, in the synthetic resin nib comprising a space of an ink capillary passage is formed in the axial direction without fusing, polyacetal homopolymer 90
A synthetic resin nib consisting of 75% by weight and 10 to 25% by weight of a polyacetal copolymer. 2. MFR of polyacetal homopolymer
(Melt flow rate JIS K-7210 test condition 4 test temperature 190 ° C, test load 21.18N) is 0.5
The synthetic resin nib according to claim 1, wherein the polyacetal copolymer has an MFR of 0.5 to 1.5 (g / 10 min).