JP5079185B2 - Firing colored pencil lead - Google Patents

Description

【００２７】
表１の結果から明らかなように、本発明範囲となる実施例１〜３ではインキの劣化が無く、繰り返し使用が可能であるのに対し、有機酸を添加していない比較例１〜３はインキが劣化しやすいことが判明した。
【００２８】
【発明の効果】
本発明によれば、体質材及び／又は結合材に窒化物を用いて焼成した多孔質焼成芯体の気孔内に有機酸を含有する染料インキが含浸されているので、焼成後の残留アンモニア、または経時的な芯体の分解により発生するアンモニアがインキ中の有機酸により中和されるため、染料が分解することがなく、鮮やかな発色性及び描線を長期にわたり保持することができる焼成鉛筆芯が提供される。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fired pencil lead having vivid color developability, a sufficient drawing density, excellent mechanical strength such as bending strength, and suitable for a thin pencil lead for a pencil or a holder.
[0002]
[Prior art]
Conventional baked colored pencil cores are often used for mechanical pencils, and as a manufacturing method thereof, a blended composition composed of a material such as boron nitride, a binder such as clay is kneaded, extruded, and further subjected to heat treatment The main production method is to form a porous core and fill the pores of the core with ink composed of a dye, a solvent, or the like.
[0003]
Further, as a method for obtaining a high-strength core, for example, as disclosed in JP-A-8-48931, etc., even if a core using silicon nitride as a binder is used, a sufficient amount of pigment dispersion can be obtained as a drawing density. It is difficult to obtain a fired core that can be impregnated with ink and has a strength higher than a practical level as a mechanical pencil core. Therefore, the present condition is that a dye must be used as the colorant for the baked colored pencil lead.
[0004]
However, it is essential to use nitrides such as boron nitride and silicon nitride for these cores, but the nitride is decomposed during firing and ammonia generated in the core remains in the core or gradually with time. It decomposes and generates ammonia.
Therefore, if the dye to be used is a type that decomposes with ammonia, such as a basic dye, there is a problem that the color of the core or drawn line is decolored or discolored.
[0005]
[Problems to be solved by the invention]
The present invention is to solve the problems of the above-described prior art fired colored pencil lead, etc., has a vivid color developability, a smooth writing taste, a sufficient drawing density, a writing line excellent in weather resistance is obtained, bending An object is to provide a fired colored pencil lead having excellent mechanical strength such as strength.
[0006]
[Means for Solving the Problems]
As a result of diligent research to solve the above-mentioned problems of the prior art, the present inventor, when using a porous fired core containing nitride, added a dye ink containing organic acid in the pores and blended it. It was found that the impregnated fired pencil lead was obtained by impregnation, and the present invention was completed.
That is, the fired colored pencil lead of the present invention is a fired colored pencil lead formed by impregnating dye ink into the pores of a porous fired core fired using a nitride as a build material and / or binder. The ink contains an organic acid.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
The fired colored pencil lead of the present invention is characterized in that an organic acid is included in the dye ink impregnated in the pores of the porous fired core fired using a nitride as the extender and / or the binder.
[0008]
In the present invention, a conventionally known porous fired core can be used, and can be formed from at least one of or both of boron nitride and silicon nitride as the binder and the extender.
When silicon nitride is used as the binder, the manufacturing method using perhydropolysilazane as the starting material disclosed in Japanese Patent Application Laid-Open No. 8-48931 by the present applicant is preferable in terms of strength. It is.
Further, when boron nitride is used as the binder, the production methods disclosed in Japanese Patent Application Laid-Open No. 6-19263 and Japanese Patent Application Laid-Open No. 11-286643 by the present applicant can be exemplified.
As an extender, it has been conventionally used as an extender of a baked colored pencil lead, and is not particularly limited as long as it is colorless or white, and any can be used, but points such as writing taste and strength And boron nitride is most preferred. Further, talc, kaolin, mica, silica, alumina and the like can be mixed and used in this boron nitride.
[0009]
As the binder, in addition to the silicon nitride and boron nitride, any conventionally known materials such as powdered silicon nitride and clay can be used, or these can be used in combination.
In addition, for example, when both the binder and the extender are not nitrides, such as a combination of clay and talc, they are not included in the present invention.
[0010]
In the present invention, the fired colored pencil core is produced by impregnating and filling a dye ink containing an organic acid in the pores of the porous fired core.
As a method for filling ink into the pores of the porous fired core, for example, the porous fired core is immersed in the ink and, if necessary, the pores of the core can be filled under pressure, reduced pressure, or the like. It can be carried out by impregnation and filling.
[0011]
In the present invention, any organic acid that can be added to and blended with the dye ink can be used as long as it can be dissolved in the solvent of the dye ink. Specific examples, glycolic acid, sulfamic acid, salicylic acid, oxalic acid, tartaric acid, acetic acid, malic acid, citric acid, benzoic acid, lactic acid, adipic acid, malonic acid, gluconic acid, succinic acid, and fumaric acid. These can be used alone or in combination.
As a method of adding and blending these organic acids to the dye ink, a method of preparing an ink by adding an organic acid after ink production, a method of preparing an ink after dissolving the organic acid in an ink solvent before ink production Etc.
[0012]
The content of the organic acid varies depending on the dye ink type, the core material, and other conditions. Therefore, the organic acid content cannot be unconditionally limited. However, in consideration of writing quality and colorability, it decomposes with ammonia in the ink composition. 1% to 30% by weight (dye: organic acid = 100: 1 to 30) , preferably 5% to 20% by weight (dye: organic acid = 100: 5 to 20), based on all dyes .
If the content of the organic acid is less than 1% by weight, it is insufficient to suppress the decomposition of the dye, and the effects of the present invention cannot be exhibited. It is difficult to completely dissolve in the ink solvent, or it is deposited over time, and the solubility of the dye also deteriorates, resulting in a deterioration in the quality of the lead.
[0013]
The fired colored pencil lead in the present invention can be produced by impregnating the porous fired core with the dye ink containing the organic acid.
Any dye ink can be used as the dye ink to be impregnated into the porous fired core.
For example, commonly used printing inks, stamp inks, ballpoint pen inks, aqueous writing inks, etc. manufactured by dissolving dyes in animal and vegetable oils, synthetic oils, alcohols, hydrocarbon oils, water, etc. Used.
However, considering the eraser erasability and stability over time of the impregnated ink, the ink solvent includes higher alcohols such as stearyl alcohol and oleyl alcohol, polyethylene glycol fatty acid esters (ethylene group number: n = 4.5 to 15) And non-volatile solutions such as polyoxyethylene alkyl ether (number of ethylene groups: n = 1 to 14) are desirable.
[0014]
As the dye, as long as it can dissolve in the solvent, an oil, water and the like to the non-volatile solution and other uses of the, alcohol soluble dyes, oil-soluble dyes, basic dyes, any of such metal-containing dyes can be used is there.
However, the present invention is intended to prevent the decomposition of the dye by ammonia caused by the porous fired core, and the dye used is one that decomposes with ammonia. The ink that uses a dye that does not decompose with ammonia is organic. This is because it is not necessary to add an acid.
It is also possible to add resins, surfactants, UV absorbers, light stabilizers, antistatic agents, etc. to the dye ink as necessary, and to improve the writing quality on the core after filling with the dye ink. It can also be impregnated with oil or the like.
It should be noted that an organic solvent having high volatility, preferably having a boiling point of 150 ° C. or lower, is used for the purpose of improving the solubility of the dye and promoting the permeability of the ink into the porous fired core by lowering the viscosity of the ink. It is also possible to add it as a solvent.
Furthermore, since the low boiling point organic solvent is removed by drying after impregnation, the ink content of the fired colored pencil lead of the present invention can be adjusted by changing the blending ratio of the low boiling point organic solvent.
[0015]
The fired colored pencil lead of the present invention configured as described above has the following effects (1) and (2).
(1) Residual ammonia after firing or ammonia generated by decomposition of the core over time is neutralized by the organic acid contained in the ink, so that the dye does not decompose and vivid color developability It becomes possible to hold | maintain the baking color pencil core and drawn line which it has for a long term.
(2) When the porous baked core is dyed by immersing it in the ink with the organic acid in the ink, the residual ammonia in the core is neutralized even if it is eluted in the ink, so the ink remaining in the container This dye does not decompose or solidify with ammonia. Therefore, the ink remaining after the porous core dyeing is excellent in storage stability and can be used for a long time.
[0016]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited at all by the following Example.
[0017]
[Example 1]
Boron nitride 40% by weight
43% by weight of vinyl chloride resin
Dioctyl phthalate (DOP) 16% by weight
Oleic acid amide 1% by weight
The above blended composition was mixed and dispersed with a Henschel mixer, kneaded with a pressure kneader and two rolls, then extruded into a thin line, and then the remaining plasticizer was removed from the mixture at 180 ° C. in air for 10 hours. After heat treatment, the temperature was raised to 1000 ° C. in a nitrogen atmosphere and fired at 1000 ° C. for 1 hour to obtain a first fired core.
The first fired core was heated and fired at 700 ° C. in the air to remove the carbonized material, thereby obtaining a white second fired core.
This second fired core was impregnated with a xylene solution of perhydropolysilazane at room temperature for 1 day, heated to 1200 ° C. in a nitrogen atmosphere and fired at 1200 ° C. for 1 hour, and a white third having a diameter of 0.57 mm. A fired core was obtained.
next,
Basic Blue 26 20% by weight
Glycolic acid 3% by weight
Ethyl alcohol 20% by weight
Polyoxyethylene lauryl ether (n = 4.5) 57% by weight
The third fired core was soaked in a blue ink made of and allowed to stand at 60 ° C. for 24 hours.
After leaving, the core was taken out from the ink, and then dried at 80 ° C. to remove ethyl alcohol, thereby obtaining a blue baked colored pencil core having a diameter of 0.57 mm.
[0018]
[Example 2]
Basic Red 1 20% by weight
DL-malic acid 3% by weight
Isopropyl alcohol 20% by weight
Lauryl alcohol 57% by weight
A third fired core similar to that in Example 1 was dipped in the red ink consisting of and left at 60 ° C. for 24 hours.
After standing, the core was taken out from the ink, and then dried at 85 ° C. to remove isopropyl alcohol to obtain a red baked colored pencil core having a diameter of 0.57 mm.
[0019]
Example 3
Boron nitride 40% by weight
Kaolin 35% by weight
Polyvinyl alcohol 18% by weight
Polyethylene glycol 7% by weight
Mix and disperse water with the same weight as the above blended composition with a Henschel mixer, knead with two rolls, adjust the water content, extrude into a thin line, and remove residual water from it in the air. After heat treatment at 105 ° C. for 15 hours, the temperature was raised to 1100 ° C. in argon gas, followed by firing at 1100 ° C. for 1 hour.
Furthermore, it was heated and fired at 700 ° C. in the atmosphere to remove the carbonized material, and a white fired core having a diameter of 0.57 mm was obtained.
next,
Basic Red 1 20% by weight
Citric acid 4% by weight
Ethyl alcohol 20% by weight
Polyethylene glycol monolaurate (n = 4.5) 56% by weight
The white fired core was dipped in a red ink consisting of and left at 60 ° C. for 24 hours.
After standing, the core was taken out from the ink, and then dried at 80 ° C. to remove ethyl alcohol to obtain a red baked colored pencil core having a diameter of 0.57 mm.
[0020]
[Comparative Example 1]
Basic Blue 26 20% by weight
Ethyl alcohol 20% by weight
Polyoxyethylene lauryl ether (n = 4.5) 60% by weight
A third fired core similar to that in Example 1 was dipped in the blue ink composed of and left at 60 ° C. for 24 hours.
After leaving, the core was taken out from the ink, and then dried at 80 ° C. to remove ethyl alcohol, thereby obtaining a blue baked colored pencil core having a diameter of 0.57 mm.
[0021]
[Comparative Example 2]
Basic Red 1 20% by weight
Isopropyl alcohol 20% by weight
Lauryl alcohol 60% by weight
A third fired core similar to that in Example 1 was dipped in the red ink consisting of and left at 60 ° C. for 24 hours.
After standing, the core was taken out from the ink, and then dried at 85 ° C. to remove isopropyl alcohol to obtain a red baked colored pencil core having a diameter of 0.57 mm.
[0022]
[Comparative Example 3]
Basic Red 1 20% by weight
Ethyl alcohol 20% by weight
Polyethylene glycol monolaurate (n = 4.5) 60% by weight
A white fired core similar to that in Example 3 was dipped in the red ink comprising, and left at 60 ° C. for 24 hours.
After standing, the core was taken out from the ink, and then dried at 80 ° C. to remove ethyl alcohol to obtain a red baked colored pencil core having a diameter of 0.57 mm.
[0023]
About the baking color pencil lead obtained in the said Examples 1-3 and Comparative Examples 1-3, the stability of the ink after dye precipitation and dyeing | staining was evaluated with the following evaluation method.
These results are shown in Table 1 below.
[0024]
[Evaluation method of dye precipitation]
After dyeing, it was visually evaluated whether there was any dye that had deteriorated and precipitated on the tip and side surfaces of the core before drying.
[0025]
[Evaluation method of ink stability after dyeing]
In the production methods of the examples and comparative examples, the state of the ink in which dyeing was repeated three times was evaluated according to the following evaluation criteria.
Evaluation criteria:
◯: There is no thickening or dye precipitation, and it is almost the same as before dyeing.
Δ: There is a little thickening or dye precipitation.
X: Thickening or dye precipitation is remarkable.
[0026]
[Table 1]

[0027]
As is apparent from the results in Table 1, in Examples 1 to 3, which are within the scope of the present invention, there is no deterioration of the ink and it can be used repeatedly, whereas Comparative Examples 1 to 3 in which no organic acid is added are It was found that the ink is likely to deteriorate.
[0028]
【Effect of the invention】
According to the present invention, since the dye ink containing an organic acid is impregnated in the pores of the porous fired core body fired using nitride as the extender and / or the binder, residual ammonia after firing, Or, since the ammonia generated by the decomposition of the core over time is neutralized by the organic acid in the ink, the dye is not decomposed, and the baked pencil core can maintain vivid color development and drawn lines for a long time Is provided.

Claims (3)

Structure material and / or binder in alcoholic solvent dye decomposed by ammonia in the pores of the fired porous baked lead with a nitride, oil-soluble dyes, basic dyes and dyes which are selected from among metal-containing dyes a baked color pencil leads obtained by impregnating an ink containing, in ink containing alcoholic soluble dye decomposed by the ammonia, oil-soluble dyes, basic dyes and dye selected from metal-containing dyes, further organic acids (However, excluding "oleic acid")   The organic acid is an organic acid selected from glycolic acid, sulfamic acid, salicylic acid, oxalic acid, tartaric acid, acetic acid, malic acid, citric acid, benzoic acid, lactic acid, adipic acid, malonic acid, gluconic acid, succinic acid, and fumaric acid. The fired colored pencil lead according to claim 1, wherein Alcohol soluble dye decomposed by the ammonia, oil-soluble dyes, with respect to 100 parts by weight of dye selected from among basic dyes and metal-containing dyes, claims, characterized in that it comprises the organic acid to 30 parts by weight Item 3. A fired colored pencil lead according to item 1 or 2.