JPS62104799A - Plastic pen body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention requires the required ink guiding ability, M chemical resistance, heat resistance, excellent abrasion resistance, high core breaking strength and buckling strength, and hard stone. The present invention relates to a plastic pen body suitable for various uses, particularly for 1 [5-speed fine point writing].

(Prior art) Pen bodies made by melt extrusion molding of thermoplastic resin are, for example,
Tokuko Sho 56-17240, Equity ++rl = 19-21
1! Using the device and method of Publication No. 32, etc. , I can also say that the cross-sectional structure of the pen body was also
Various structures are disclosed in Japanese Utility Model Publication No. 418 and Japanese Utility Model Publication No. 58-35508.

To summarize, the pen body formed by such an apparatus and method is produced by extruding and stretching a molten resin into the cross-sectional shape of the pen body using a die of an extrusion molding machine, or by extruding a molten resin into a cross-sectional structural shape of the pen body using a die of an extrusion molding machine, or by pouring a large number of resin into an extrusion molding machine. The molten resin is discharged from the die with the holes 1. A rod-shaped body is formed by instantaneously contacting and fusing parts of their mutual surfaces and stretching it to form a desired ink guide path in the axial direction.The rod-shaped body is then cut to an appropriate size and cut (d). be.

By the way, in conventional pen bodies of this type, polyacecool copolymer is mainly used as the resin. This depends on the copolymer not only satisfying the moldability required by the method and apparatus described above, but also having appropriate stiffness and abrasion resistance to be effective in fine-grain writing.

Recently, in addition to the miniaturization of the pen body itself, new uses for devices such as plotters and recorders have led to the extension of the effective distance for fine-point writing and the development of heat resistance that can handle the 1F friction heat of high-speed writing. There is a new demand for chemical resistance that can handle various inks and buckling strength that can handle rough impact loads.

In this respect, there is a problem in that pen bodies made of general-purpose crystalline polyaretal copolymers cannot meet the above requirements.

(Problems to be Solved by the Invention) The problems to be solved by the present invention are to satisfy the above-mentioned requirements and to produce a wear-resistant material having a desired cross-sectional structure by the conventionally known extrusion molding as described above. The object of the present invention is to provide a hard pen body that is ideal for high-speed, fine-print writing and has significantly improved heat resistance, chemical resistance, and buckling strength as well as heat resistance.

(Means for Solving the Problems) The present inventors have conducted research on the above problems, and have found that engineering plastics with excellent mechanical properties such as 0 (thermal resistance, chemical resistance, 1 bending strength), etc. Polynyderneedleketone (PEEK), which is described as
I paid attention to. However, there was no disclosure of effective technology for applying this polyetheretherketone to pen bodies, which hindered its practical application, but after repeated intensive research and experiments, the melt viscosity of the polyetheretherketone was is less than 4000 poise, the pen body with the desired cross-sectional structure will be
They found that the problem in question can only be achieved when the melt viscosity is selected to be higher than a specific index.

In other words, the means taken by the present invention to achieve the above-mentioned problems is that in a plastic pen body formed by melt extrusion molding of a thermoplastic resin to have a cross-sectional structure having an ink guiding path in the axial direction, the above-mentioned resin is used. is polyetheretherketone and has a melt viscosity of 4000 poise or more.

(Example) Hereinafter, the present invention will be explained in detail using shellfish examples.

The effectiveness of polyether ether ketone with a melt viscosity of 4000 DOiSe or more was demonstrated in Japanese Patent Publication No. 56-1724, which is widely used in extrusion molding of pen bodies and is a basic manufacturing method.
This will be explained from the aspect of moldability by exemplifying Publication No. 0.

Specifically, the manufacturing method using the above-mentioned molding device involves providing a shaping opening with a shape similar to the intended cross-sectional shape of the pen body (△) to be molded, and a melt flow rate adjustment hole behind this shaping opening. Polyneedleetherketone in a molten state flows from the die through the melt flow rate adjustment hole, and the shaping openings form the desired cross-sectional shape J, that is, the outer shell (1), each protrusion (2), and the ink. '', fi, extrude and stretch while keeping the outline of Chiro (3).In addition, the envelope of the shaping opening is circular or linear. .

Here, if the melt viscosity of the resin is less than 4000 poise, the viscosity is too low and it lacks shape retention.
, the formation of a guideway (3) cannot be avoided.

Also, if the melt viscosity is extremely high, the viscosity will be too high.
It is difficult to stretch and has poor formability, and the back pressure applied to the die is large and can damage the die.

Therefore, the melt viscosity is 600 poise, which is more than 4000 poise.
0 to po i sc is preferred.

This melt viscosity was measured using a Koka type flow tester at a heating temperature of 40
Measured at 0°C, heating time 5 minutes, nozzle diameter 2mmφ, land depth 2, simple z2okgr.

Figure 1 shows an example of a pen body (Δ) molded by the above manufacturing method, and is made of polyetheretherketone (melt viscosity 10860ρ0isc) at a molding temperature of 372°C from a die.
Extrude and stretch to form a ream f! with an outer diameter of 0.5 mmφ! It is formed by obtaining an L rod-shaped body, cutting it to a required length, and grinding it.

The pen body (A) thus obtained has the following properties. The polyacetal copolymer pen body for comparison was a 1υ-cross-sectional shape molded by the same manufacturing method as above except for the molding temperature (177°C).

(Effect of the invention) Therefore, the present invention has the following advantages.

■ The pen body is made of polyacetal copolymer, which satisfies the melt extrusion molding process, quickly achieves the desired cross-sectional shape, has the required ink guide path, and has excellent heat resistance, abrasion resistance, buckling strength, and core breakage strength. This is a marked improvement over the conventional method, making it ideal for high-speed fine-character writing on blocks and recorders.

■ Polyacecool copolymer can be applied to thinner diameters of 0 and 5 φ or less, which cannot be denied the lack of strength, so it is suitable for high-speed fine writing on plotters and recorders, and for drafting and line drawing pens, especially for line width. is most suitable for a 0.1mm pen tip.

■ Excellent chemical resistance except for sulfuric acid, and can be used with inks of various ingredients.

[Brief explanation of drawings]

FIG. 1 is an enlarged cross-sectional view illustrating the pen body of the present invention. (A) in the figure is a pen type

Claims (1)

[Claims] A plastic pen body formed into a cross-sectional structure having an ink guide path in the axial direction by melt extrusion molding of a thermoplastic resin, wherein the resin is polyether ether ketone and has a melt viscosity of 4000 poise or more.