JP2003342511A - Writing utensil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a writing utensil without causing a phenomenon (blurred when evaluated as a handwriting) lowering the amount of jetting at the penpoint of the writing utensil during use when preserved over a long period. <P>SOLUTION: The writing utensil uses the penpoint made of a polyacetal resin. An ink for the writing utensil comprises at least a colorant containing C.I. Direct Black 19 and water. The content of an unreacted product which is a dye intermediate derived from the C.I. Direct Black 19 is ≤5 wt.% based on the C.I. Direct Black 19. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a writing instrument using a nib made of polyacetal resin, and in particular,
The present invention relates to a writing instrument that prevents fading and clogging with time.

[0002]

2. Description of the Related Art Conventionally, a resin nib is known as a pen tip used in a writing instrument. As the material, polyacetal resin, polybutyl terephthalate resin, aromatic nylon resin, modified polyphenylene ether resin, polyacrylate resin and the like can be used in terms of moldability and hardness. A polyacetal resin is particularly preferred and used because of its smooth writing feel.

Dyes and / or pigments are widely used as colorants in the water-based inks for writing instruments. In particular, dyes are generally dissolved in ink,
Inks using dyes as colorants are widely used because of their excellent stability over time.

By the way, since the dye is easily dissolved in a solvent such as water as described above, it has a problem that it is inferior in water resistance when evaluated as a handwriting. Therefore, as a dye, C.I. I. It is known to use Direct Black 19. This C. I.
The dye called Direct Black 19 has very good water resistance when it becomes a handwriting, as compared with various other dyes.

[0005]

However, in a writing instrument using a pen tip made of polyacetal resin, the ink for the writing instrument contains C.I. I. The one using Direct Black 19 had a phenomenon that the amount of ink discharged from the pen tip of a writing tool was reduced (slightly evaluated as handwriting) during use when stored for a long time. An object of the present invention is to provide a pen tip made of polyacetal resin and C.I. I. (EN) A writing instrument using an ink containing Direct Black 19, which is less likely to cause scratches on a handwriting even when stored for a long period of time.

[0006]

The present invention provides a writing instrument using a pen tip made of polyacetal resin, wherein the ink of the writing instrument is C.I. I. A colorant containing at least Direct Black 19, and water, and C.I.
I. The content of the unreacted product, which is a dye intermediate derived from Direct Black 19, is C.I. I. Direct black 19
The writing tool is characterized by being 5% by weight or less.

The details will be described below. The nib has moldability,
Since the hardness and the like and the smoothness of writing feel are preferable, the one made of polyacetal resin is used. When the writing instrument is a ballpoint pen, the tip of the ballpoint pen used is composed of a ball and a ballpoint pen tip made of polyacetal resin that holds the ball.

The colorant is C.I. I. Direct black 1
9 alone or C.I. I. It can be used in combination with Direct Black 19 and a direct dye having the structure of Chemical formula 1. The amount used is 5 to 20% by weight based on the total amount of the water-based ink for writing instruments.
Is preferred.

C. I. Direct Black 19 is a black direct dye having four azo groups. C. I. Direct black 19 has much better water resistance than other dyes when it is handwritten, and is preferred as a colorant used in a water-based ink for writing instruments. In addition, this C. I. The ink using the direct black 19 has poor wettability with respect to polypropylene or the like, and therefore when used by being filled in an ink containing portion made of transparent or translucent polypropylene, the visibility of the remaining ink amount is good. Commercially available products include Water Black # 7 (manufactured by Orient Chemical Industry Co., Ltd.) and the like.

The C.I. I. Direct Black 19 has a content of unreacted products, which are dye intermediates, of C.I. I. It should be 5% by weight or less based on the direct black 19. this is,
Since the water black # 7 and the like are industrial products, they contain unreacted dye intermediates and inorganic salts as impurities. This is because it is possible to suppress the occurrence of blurring by adjusting the content of the dye intermediate among these impurities. If the content of the unreacted product, which is a dye intermediate, exceeds 5% by weight, the discharge amount at the pen tip of the writing instrument using the above-mentioned pen tip decreases when stored for a long time (handwriting). When evaluated as, it will cause). Further, the above C. I. When using Direct Black 19 alone, the content of the dye intermediate in the dye is preferably 3% by weight or less. The amount of the dye intermediate is C.I. I. The aqueous solution of Direct Black 19 and xylene were mixed and stirred, and allowed to stand to separate them, and the supernatant thereof was subjected to a spectroscopic analysis for the xylene extraction phase, and the peaks in the vicinity of 400 to 410 nm were confirmed and quantified. The dye intermediate having the maximum absorption wavelength at this peak is a substance called chrysoidine, which can be quantified by a calibration curve method using a solution of the reagent. The method for removing the dye intermediate is not particularly limited, and a generally known method can be used. Examples include salting out method and reverse osmosis membrane method. Further, in the salting-out method, heating filtration is also an effective means for removing the dye intermediate more sufficiently. In addition, the salting-out method and the reverse osmosis membrane method can remove not only the dye intermediate but also the inorganic salts such as sulfate ion and chlorine ion contained in the above-mentioned commercially available dyes, so that they can be used especially at low temperature. When the ink is stored for a period of time, it is possible to prevent a decrease in the ejection amount at the pen tip (usefulness when evaluated as handwriting) that occurs during use.

Direct dyes having the structure of Chemical formula 2 are usually C.I.
I. A derivative of a trisazo direct dye called direct black 154, which is an ordinary C.I. I. Compared to Direct Black 154, the difference is that sodium sulfonate is present on the benzene ring at the right end of Chemical formula 2, and a methyl group (usually a hydroxyl group) is substituted on the naphthalene ring. As a commercial item, Water-Black # 130-L
(Orient Chemical Co., Ltd.) and the like.

[0012]

[Chemical 2]

The aforementioned C. I. Direct Black 19 is a tetrakisazo dye, which has a low solubility in water and has a narrow pH range of 10 to 11 in which it is stable.
On the other hand, the direct dye having the structure of Chemical formula 1 is a trisazo dye, has many sulfonic acid groups, has high solubility in water, and has a wide stable pH range of 7 to 11. However, there is a drawback that the water resistance is poor due to its solubility. C. I.
Although it is possible to obtain an ink stable over time by setting the content of the unreacted product, which is a dye intermediate of Direct Black 19, to 5% by weight or less, it is more stable over time and the ink density is obtained. It is most effective to use a direct dye having the structure of Chemical formula 1 together. The amount used is C.I. I. It can be used in an amount of 0 to 500% by weight based on Direct Black 19.

Water is used as a main solvent, and its amount is preferably 30 to 95% by weight based on the total amount of the aqueous ink for writing instruments.

In addition to the above essential components, various conventionally known additives for water-based inks can be used.
For example, in order to improve the drying resistance of the nib, a glycol-based solvent such as ethylene glycol, diethylene glycol, or thiodiglycol, a known water-soluble organic solvent such as glycerin, and / or urea, ethylene urea, or a derivative thereof may be used alone or in combination. Can be mixed and used.

Further, in order to adjust the viscosity of the ink, a thickening water-soluble polymer such as polyvinyl alcohol, polyvinylpyrrolidone, guar gum or xanthan gum may be used if necessary.

Further, for the complementary color, the C.I. I. In addition to the direct black 19 and the direct dye having the structure of Chemical formula 1, known acid dyes or direct dyes can be used.

In addition, various additives such as antiseptics, antifungal agents, rust preventives, lubricants, defoamers, surfactants and pH adjusters may be appropriately used alone or in combination depending on the purpose and need. be able to.

The water-based ink used in the writing instrument according to the present invention can be easily prepared by a conventionally known method such as mixing and stirring the above-mentioned various components with a known stirrer.

[0020]

The writing instrument according to the present invention suppresses the precipitation of insoluble substances at the tip of the pen due to the reaction between the horimarin generated from the polyacetal resin used for the nib and chrysoidine which is a dye intermediate. It is presumed that the phenomenon that the discharge amount at the pen tip during use of the writing implement after storage for a long period of time (decay when evaluated as handwriting) does not occur.

[0021]

EXAMPLES The present invention will now be described in more detail with reference to examples.

Preparation of Dye Aqueous Solution A Water Black # 7 (Orient Chemical Industry Co., Ltd.)
8.7 parts by weight of water, 83 parts by weight of water, and 8.3 parts by weight of hydrochloric acid are mixed and stirred, filtered, and the insoluble residue is washed with 120 parts by weight of water. Water and a 25% aqueous sodium hydroxide solution were added to this insoluble residue and dissolved by stirring to give a dye aqueous solution A (CI Direct Black 19: 19.2) having a pH of 10.5.
% By weight, dye intermediate content: C.I. I. 4.5% by weight based on Direct Black 19).

Preparation of Dye Aqueous Solution B 8.7 parts by weight of Water Black # 7 (described above), water 83
By weight, 8.3 parts by weight of hydrochloric acid are mixed and stirred at 40 ° C., filtered, and the insoluble residue is washed with 120 parts by weight of water heated to 40 ° C. To this insoluble residue, water and a 25% aqueous sodium hydroxide solution were added and dissolved with stirring, and a dye aqueous solution B (CI Direct Black 19:19.
8% by weight, dye intermediate content: C.I. I. 0.6% by weight based on Direct Black 19).

Preparation of Dye Aqueous Solution C 35 parts by weight of Water Black # 7 (described above) and 65 parts by weight of water were dissolved by stirring to prepare a dye aqueous solution C having a pH of 10.5 (adjusted with 25% sodium hydroxide aqueous solution). CI direct black 19: 19.0% by weight, dye intermediate content: 6% by weight relative to CI direct black 19).

[0025] The above components were stirred and mixed using a stirrer to obtain a black aqueous ink.

Ink for Examples 2 Dye Aqueous Solution A 11.1 parts by weight Water Black # 130-L 35.0 parts by weight Ethylene glycol 5.0 parts by weight Thiodiglycol 10.0 parts by weight Urea 9.0 parts by weight Parts Proxel GXL 0.2 parts by weight water 29.7 parts by weight The above components were stirred and mixed using a stirrer to obtain a black aqueous ink.

Ink for Example 3 Aqueous dye solution B 50.0 parts by weight Thiodiglycol 9.0 parts by weight Ethylene urea 10.0 parts by weight Proxel GXL 0.2 parts by weight Water 30.8 parts by weight The above components were stirred. And mixed with stirring to obtain a black aqueous ink.

Ink for Examples 4 Dye aqueous solution B 18.1 parts by weight Water Black # 130-L 16.3 parts by weight C.I. I. Acid Red 87 0.2 parts by weight C.I. I. Acid Blue 9 0.2 parts by weight C.I. I. Acid Yellow 42 0.2 parts by weight Ethylene glycol 5.0 parts by weight Thiodiglycol 10.0 parts by weight Urea 10.0 parts by weight Benzotriazole (rust inhibitor) 0.4 parts by weight Proxel GXL 0.2 parts by weight water 39 0.4 parts by weight The above components were stirred and mixed using a stirrer to obtain a black aqueous ink.

Ink for Comparative Example 1 Dye Aqueous Solution C 50.0 parts by weight Thiodiglycol 9.0 parts by weight Urea 10.0 parts by weight Proxel GXL 0.2 parts by weight water 30.8 parts by weight The above components were mixed using a stirrer. The mixture was stirred and mixed to obtain a black aqueous ink.

Ink for Comparative Example 2 Dye aqueous solution C 27.1 parts by weight Water Black # 130-L 4.1 parts by weight C.I. I. Acid Red 87 0.2 parts by weight C.I. I. Acid Blue 9 0.2 parts by weight C.I. I. Acid Yellow 42 0.2 parts by weight Ethylene glycol 5.0 parts by weight Thiodiglycol 10.0 parts by weight Urea 10.0 parts by weight Benzotriazole 0.4 parts by weight Proxel GXL 0.2 parts by weight Water 42.6 parts by weight Above The components were stirred and mixed using a stirrer to obtain a black aqueous ink.

Examples 1 to 4 and Comparative Examples 1 and 2 The water-based inks obtained in the inks 1 to 3 and Comparative Example 1 described above were used as writing instruments having a nib made of polyacetal resin (Plaman, JM20, Pentel). 2.0)
It was filled with g to make Examples 1 to 3 and Comparative Example 1. Similarly, the water-based inks obtained with Ink for Example 4 and Ink for Comparative Example 2 were used as a writing instrument having a ballpoint pen tip made of polyacetal resin (Ball Pentel, B100, Pentel Co., Ltd.).
Were filled with 2.2 g to obtain Example 4 and Comparative Example 2. Handwriting was performed on woodfree paper using these writing instruments. Furthermore, after leaving for a certain period with the pen tip facing up or down under the condition of temperature of 50 ° C. and humidity of 30%, handwriting was performed again on the high-quality paper, and the change in handwriting before and after the leaving was observed.
At the time of assembly, all of the above writing instruments could be written well. Evaluation: ◯: No fading Δ: Slight fading ×: Fading results are shown in Table 1.

[0032]

[Table 1]

[0033]

As described above in detail, the writing instrument according to the present invention has a phenomenon that the discharge amount at the pen tip of the writing instrument decreases when used for a long period of time (it is faint when evaluated as handwriting). It is an excellent one.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C350 GA04 GA11 HA16 NA10 NA11                       NA19 NC02 NC20                 4J039 BC42 BC65 BC77 BC79 BE02                       CA03 CA06 EA41 EA42 GA26                       GA27 GA28

Claims (2)

[Claims] 1. A writing instrument using a pen tip made of polyacetal resin, wherein the ink of the writing instrument is C.I. I. A colorant containing at least Direct Black 19, and water, and C.I. I. Direct black 1
The content of the unreacted product, which is a dye intermediate derived from C.9, is C.I.
I. Writing instrument characterized by being 5% by weight or less with respect to direct black 19. 2. The writing instrument according to claim 1, wherein the colorant further comprises a direct dye having the structure of Chemical formula 1. [Chemical 1]