JPH0483696A - Writing method with pencil lead - Google Patents

Abstract

PURPOSE:To vary a writing trace density by writing with a pencil lead at different upper and lower temperatures at a softening temperature of an oily matter as a boundary in a method for citing with the lead in the presence of the oily matter in pares of a baked lead. CONSTITUTION:An oily matter is heated while increasing or decreasing pressure as required, and dipped in baked lead to be easily existed in pores of the lead. Here, the lead includes, for example, baked organic lead, clay sintered lead, etc. Its porosity is desirably about 20-60% (according to a known benzyl alcohol immersing method) by considering relationship to its strength. In a thermal writing, for example, a nichrome heater is disposed at the end pipe of a mechanical pencil or a lead holder, externally emitted with a light, high frequency- heated, etc. Or a writing surface may be heated. Two or a plurality of types of solid oily matters at the ambient temperature may be employed. The plurality of the matters can easily vary writing trace density in multiple stages.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for writing with a pencil lead in which an oily substance is present in the pores of a fired core.

(Conventional technology) Pencil lead is not only used as lead for wood-based pencils.

It is widely used as lead in mechanical pencils and even as writing lead in devices such as plotters. The term "pencil lead" itself is disproportionate.

Typical types of this pencil lead are: 1) A type that is simply shaped with a binder like ordinary crayons, passes, etc., and a 1) type that is simply shaped with a binding material like ordinary crayons, passes, etc., and 1) a type that is simply shaped with a binding material, and a type that is subjected to high-temperature heat treatment to obtain a fired core, and this fired core has the following properties. Some have oily substances present in their pores. The latter, ie, fired pencil lead, has excellent strength, so at present, fired pencil leads are used exclusively as small-diameter pencil leads. In particular, those that use an organic binder and graphite as the main materials have a smoother writing feel, so it is possible to improve the writing quality by changing the type of binder or adjusting the size and amount of pores. Many studies have been made to improve strength and density.

(Problems to be Solved by the Invention) Although the fired pencil lead has the above-mentioned advantages, it is not without drawbacks. One of them is setting the handwriting density.

Currently, pencil leads are given density symbols such as HB and B. You can change the density of your handwriting to some extent by changing the writing pressure, but if you use a low writing pressure, your handwriting will become mottled and unclear, and if you use a high writing pressure, the pencil lead will crumble or break. Pencil leads cannot change the density of handwriting as much as desired, so by changing the formulation and manufacturing conditions, it is possible to select a suitable density for each use.

However, doing so requires preparing many types of pencil leads. Particularly when using a machine such as a plotter, it becomes extremely troublesome to replace the pencil lead every time the density of handwriting is changed.

(Means for Solving the Problems) The present invention is a method for writing with a pencil lead in which an oily substance is present in the pores of a fired core, the pencil lead being The gist of this paper is a method of writing with a pencil lead, which is characterized by writing at different temperatures on the top and bottom.

The details will be explained below.

The fact that the density of handwriting varies depending on the type of oily substance present in the pores of the fired core can be understood by actually writing with various oily substances impregnated. The present inventors have focused on the fact that this change in handwriting density is caused by the softness of the oil rather than the type of the oil. When the same oily material is changed in its softness, the change in handwriting density is greater than when different types of oily material with approximately the same softness are used.

The softness of an oil can be changed by heating the oil. Moreover, if the heating involves a change in state, such as solid or liquid state, the change in softness will be large. In other words, depending on the type of oily substance, the expression of physical properties such as melting temperature, softening temperature, pour point, etc. differs, but these temperatures (in the present invention,
There is an extremely large difference in softness above and below the boundary (typically called the "soft melting temperature"). Therefore, by writing at different temperatures above and below this soft melting temperature,
The density of handwriting can also be changed significantly.

The oil used may be one that is liquid at room temperature, such as liquid paraffin, silicone oil, spindle oil, machine oil, etc. If the heating is negative heating, that is, cooling, the state changes. However, the heating is still positive heating, i.e.
Heating to raise the temperature is easier. Therefore, it is preferable to select an oil that is solid at room temperature6.
- Examples include carnauba wax, microcrystalline wax, wood wax, beeswax, ceresin wax, paraffin wax, bohemia wax, montan wax, low molecular weight polyethylene wax, rosin resin, terpene polymer, modified xylene resin, C6 petroleum resin, Examples include fatty acid esters, phthalate esters, and various surfactants. Oily substances that are liquid at room temperature may be used in combination with these. Also, two or more types of oily substances that are solid at room temperature can be used in combination. By using multiple oily substances in combination, the density of handwriting can be easily changed in multiple stages. However, when using a plurality of oily substances in combination, it is preferable to combine oily substances with a difference in melting temperature of 10° C. or more in order to facilitate temperature control. Furthermore, if the amount of one of the types used in combination is too small, the contribution of that oily substance to changes in handwriting density will be small, so it is better to use about 20% by weight of the one used the most.

These oily substances are pressurized or depressurized as necessary (
It can be easily made to exist in the pores of the fired core by heating it (positively) and immersing the fired core in it. Here, the fired core may be an organic fired core, a clay sintered core, or the like. Further, the porosity is preferably about 20 to 60% (based on the known benzyl alcohol impregnation method), considering the relationship with strength. In addition, for heating writing, for example, placing a nichrome heater on the tip pipe of the mechanical pencil or lead holder, irradiating light from the outside, or applying high-frequency heating may be used as appropriate.
You can also heat the writing surface.

(Example) Core 1 semi-polyvinyl chloride 30M parts graphite
50 parts by weight carbon black
5 parts by weight stearate
1 part by weight Dioctyl phthalate 10 parts by weight The above materials were mixed thoroughly with three rolls, extruded into a fine wire, heat-treated in air to 300'C, then heat-treated to 1000°C in an inert atmosphere, Nominal fio, 5mm
Fired mechanical pencil lead (porosity: approx. 35%)
) was obtained.

1 CL) f row east ■ Chlorinated polyvinyl chloride 30 parts by weight graphite
45 parts by weight amorphous silica
2 parts by weight stearate
1 part by weight Dioctyl phthalate 8 parts by weight The above materials were thoroughly kneaded with three rolls, extruded into a fine wire shape, heat-treated in air to 300°C, then heat-treated to 1000°C in an inert atmosphere to form a A fired mechanical pencil lead (porosity: about 23%) with a diameter of 0.5 mm was obtained.

Sintered core 3 - Polyvinyl chloride-vinyl acetate copolymer 30 parts by weight Graphite 50 parts by weight Carbon black 2 parts by weight Polymethyl methacrylate fiber (diameter approx. 10 μm, length approx. 0.5 mm) 3 parts by weight stearic acid Salt 1 part by weight Dioctyl phthalate
15 parts by weight of the above material was sufficiently mixed with three rolls, extruded into an MJa shape, heat-treated in air to 300'C, then heat-treated to 950°C in an inert atmosphere,
Fired mechanical pencil lead with a nominal diameter of 0.5 mm (
Porosity: about 55%) was obtained.

Core 4 quasi-montmorillonite clay 15 parts by weight Hylosite clay 15 parts by weight graphite
50 parts by weight carbon black
Type 3 plate part Put the above materials into a wet ball mill (moisture 65
%) After being sufficiently dispersed by rotating for 50 hours, it was dehydrated with a squeezing machine until the water content was about 25%, further kneaded with a roll, extruded into a thin wire shape, dried, and heat treated at 1000 ° C. A fired mechanical pencil lead (porosity: about 30%) with a nominal diameter of 0.9 mm was obtained.

<Example 1> The fired core (1) was immersed in a 7=3 mixture of microcrystalline wax (melting temperature: about 70°C) and low molecular weight polyethylene wax (melting point: about 110°C) for 3 hours (14
0'C) was used as a pencil lead. Place this pencil lead in the holder of the plotter, and set the temperature of the heating section to 20℃, 8℃.
It was written at 100°C, 120°C, and 140°C.

(Examples 2 to 4) In Example 1, the fired core (1) was replaced with the fired core (2),
Everything was the same as in Example 1 except that the fired core (3) and the fired core (4) were changed.

<Example 5> The fired core (1) was coated with montan wax (melting temperature approximately 80°C).
) and spindle oil (pour point 0°C or lower) for 2 hours (120°C) to prepare a pencil lead. This pencil lead was housed in a holder of a plotter, and the temperature of the heating section was set at 20°C, 80°C, 100°C, and 120°C, and the plotter was used for writing.

<Example 6> The fired core (3) was mixed with Hyrosin (rosin-based resin manufactured by Yasuyu Kogyo ■; softening temperature about 95°C), Ceresin wax (melting temperature about 72°C), and liquid paraffin (pouring point O'C or lower). ) was immersed for 1 hour (at 120°C) into a pencil lead. Place this pencil lead in the holder of the plotter, and set the temperature of the heating section to 20℃, 80℃, and 100℃.
, and was written at 120°C.

<Example 7> A pencil lead was prepared by immersing the fired core (1) in microcrystalline wax for 3 hours (120°C). This pencil lead was placed in the holder of the plotter, and the heating section was set at temperatures of 20°C, 80°C, ], 00°C, and 120°C, and writing was performed.

<Example 8> A pencil lead was prepared by immersing the fired core (1) in low molecular weight polyethylene wax for 3 hours (140°C). This pencil lead was housed in a holder of a plotter, and writing was carried out at the set temperatures of the heating section of 20°C, 80°C, 100°C, 120°C, and 140°C.

<Comparative Example 1> The fired core (1) was immersed in spindle oil for 3 hours (]O
(0°C) was used as a pencil lead. Place this pencil lead in the holder of the plotter, and set the temperature of the heating section to 20℃, 80℃.
'C I wrote it down at 1100 degrees Celsius.

<Comparative Example 2> The fired core (4) was immersed in liquid paraffin for 3 hours (1
00°C) was used as a pencil lead.

This pencil lead was housed in a holder of a plotter, and the temperature of the heating section was set at 20°C, 80°C, 100°C, and 120'C, and writing was performed.

The results of examining the handwriting density for each side above are shown below.
Shown in 1. Measurements were made in accordance with JISS6005 by vertical writing (plotter) on high-quality paper with a load of 400 g.

Table-1 Heating temperature Example 1 20°C 80°C 100'C 12O°C 140°C Example 2 20°C 80°C 100'C 12O°C 140°C Example 3 20°C Concentration (D) Concentration symbol 0.17 F O,30HB O,32HB O,37B 0.38 B 0.08 H O,18F O,19, F O,30HB O,31HB O,18F Example 4 Example 5 Example 6 Example 7 80°C] - 00℃ 120℃ 406C 20℃ 80℃ 100℃ 120℃ 140℃ 20℃ 80℃ 100℃ 120℃ 20'C 80℃ 100℃ 120℃ 20℃ 80℃ 100℃ 4゜B B B B B B B B B 120° C0,38B Example 8 20℃ 0.15 ) (80℃
0.15 H 100″CO, 15H 120°C 0.28 HB 140″c O, 30HB B Comparative Example 1 20°C0, 37B 80°C 0. 37 B100°CO,
38B Comparative Example 2 20'CO, 27HB 80°CO, 29HB 100°C 0.29 HB120'CO,
30HB In the above -]-, in Comparative Examples 1 and 2, there is almost no difference in handwriting density (D) even if the temperature is changed. but,
In each example, the difference in handwriting density increases as the density symbol changes.

This is a method for writing with a pencil lead in which an oily substance is present in the pores of a fired core, in which the pencil lead is held at a temperature of the upper and lower parts with the melting temperature of the oily substance as a boundary. According to the writing method using a pencil lead of the present invention, which is characterized by writing, the density of handwriting can be sufficiently changed even with one pencil lead, and therefore, for example, when using a machine such as a plotter, If you have one, you won't have to replace the pencil lead every time you change the density of your handwriting.

Claims (1)

[Claims] A method for writing with a pencil lead in which an oily substance is present in the pores of a fired core, characterized in that the pencil lead is used at different temperatures above and below the melting temperature of the oily substance. A method of writing using a pencil lead.