JPH0852981A - Writing tool using water gel ink - Google Patents

Abstract

PURPOSE:To prevent a backflow preventing agent from sticking to the inner wall of an ink storage pipe, with a possibility of decreasing the consumption of the backflow preventing agent, and control the discharge of ink so that it is constant against a change in environmental conditions such as the temperature and humidity of a site where this writing tool is used with the subsequent availability of superb writing touch and the elimination of an incident that the backflow preventing agent might spew out by an impact caused by the dropping of the writing tool. CONSTITUTION:A water gel ink 4 is loaded in an ink storage pipe 3 with a nib part 2 provided at the tip, then a backflow preventing agent 5 is charged behind the ink 4, and a lid part 6 with a smaller outer diameter than the inner diameter of the ink storage pipe 2 is provided on the rear end of the backflow preventing agent 5. Thus the writing tool 1 using the water gel ink is constituted as described.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument such as a neutral ballpoint pen using an aqueous gel ink and an anti-reflux agent, and more particularly to a writing instrument using an aqueous gel ink which solves various problems caused by the anti-reflux agent. is there.

[0002]

2. Description of the Related Art An ink obtained by imparting thixotropy to a low-viscosity aqueous ink is known as an aqueous gel ink. A writing instrument using the above conventional water-based gel ink generally has a structure shown in FIG. That is, conventionally, as shown in FIG. 3A, a water-based gel ink 33 is filled inside an ink containing tube 32 having a pen tip 31 at the tip, and a backflow preventive agent 34 is filled behind the ink 33 to make a writing instrument. Made up thirty.

The backflow preventive agent 34 advances in the direction of the pen tip 31 together with the ink 32 as the ink 32 is consumed.
It is provided for the purpose of suppressing the evaporation of No. 3 and preventing the ink from flowing back when a force is applied to the writing instrument or when the writing instrument is placed in a high temperature environment. Conventionally, as a backflow preventing agent, a substance such as silicone grease which is viscous and incompatible with an aqueous gel ink has been used.

[0004]

The backflow preventive agent 34 has a very high viscosity as compared with the ink 33 and has a large adhesive force with the inner wall 35 of the ink containing tube 32. Therefore, FIG.
Writing instrument 30 using the conventional aqueous gel ink shown in (a)
After using, as shown in (a) of the same figure, when the ink 33 is consumed by using a writing instrument, the backflow preventive agent 34 moves in the direction of the pen tip 31 at the tip together with the ink 33. There is a problem that the agent 34 adheres to the inner wall 35 of the ink containing tube and gradually decreases, and the amount of the agent 34 is much smaller than the amount initially filled. As shown in FIG. 3A, when the backflow preventive agent 33 is reduced, there is a risk that the ink may backflow backward or the water-based gel ink may be dried. Therefore, conventionally, a countermeasure has been taken by filling a large amount of the backflow preventing agent 34 in anticipation of the amount of the backflow preventing agent 34 adhering to the inner wall of the ink containing tube.

However, if the backflow preventive agent is filled in a large amount as described above, the backflow preventive agent such as silicone grease is a very expensive raw material and the cost is increased, and the inside of the ink containing tube is increased. However, there has been a problem that the proportion of the backflow preventive agent that cannot be used directly for writing increases, and the ink filling space decreases.
Further, the outflow of the aqueous gel ink from the pen tip is closely related to the filling amount of the backflow preventing agent. For example, if the adhesive force of the backflow preventive agent with the inner wall of the ink containing tube becomes large, the force for causing the ink to flow out becomes weak and the ink does not come out easily. Also, if the adhesive force between the backflow preventive agent and the inner wall of the ink containing tube becomes small,
Contrary to the above condition, the ink ejection is improved. Therefore,
With this type of conventional writing instrument, if the backflow preventive filling amount changes when it adheres to the inner wall of the ink storage tube, the ink outflow rate changes, so the writing quality is consistent from start to finish. There was a drawback that it could not be obtained.

The present invention is intended to solve the above-mentioned drawbacks of the prior art, and it is possible to prevent the backflow preventing agent from adhering to the inner wall of the ink containing tube and reduce the amount of the backflow preventing agent used. Excellent in writing quality with constant ink output against changes in environment such as temperature and humidity at the place of use, and furthermore, there is no problem that the backflow preventer pops out even when shocked such as falling on a writing instrument, An object is to provide a writing instrument using an aqueous gel ink.

[0007]

A writing instrument using a water-based gel ink of the present invention comprises a water-based gel ink whose viscosity is adjusted inside an ink containing tube having a pen tip at the tip, and a fluid ink which is dried. And a backflow preventive agent for preventing backflow of ink, the writing instrument being filled with a lid body having an outer diameter smaller than the inner diameter of the ink containing tube at the rear end of the backflow inhibitor. Characterize.

【Example】

The present invention will be described in more detail below with reference to the drawings. FIG. 1 shows an example of a writing instrument using the aqueous gel ink of the present invention (hereinafter sometimes simply referred to as writing instrument),
(A) is a sectional view, (b) is an enlarged view of the vicinity of the rear end of the ink containing tube of the lid, (c) is C- in (b).
It is a C line sectional view, and (d) is a sectional view showing a state after use.

In the writing instrument 1 of the present invention, as shown in FIG. 1A, an aqueous gel ink 4 is filled in an ink containing tube 3 having a pen tip portion 2 at its tip, and a backflow preventive agent 5 is provided behind the ink 4. In the writing instrument sequentially filled with, the lid 6 having an outer diameter smaller than the inner diameter of the ink containing tube 2 is provided at the rear end of the backflow preventing agent 5.

In the writing instrument 1 of the present invention, the lid 6 is located behind the backflow preventing agent 5 and is likely to adhere to the inner wall 7 of the ink containing tube 3 when the backflow preventing agent 5 moves toward the pen tip portion. The backflow preventive agent 5 is scratched to move the backflow preventive agent 5 to the pen tip portion and to prevent the backflow preventive agent from flowing out near the center of the cross section of the ink containing tube 3.

The outer diameter of the lid 6 may be formed smaller than the inner diameter of the ink containing tube, but it is preferable that the outer diameter of the lid 6 is closer to the inner diameter of the ink containing tube, so that the ink containing the backflow preventive can be more reliably contained. It is possible to prevent the backflow preventive agent from adhering to the inner wall of the tube and from flowing around the center of the ink containing tube. The specific size of the lid is 9 times the inner diameter of the ink containing tube.
It is preferably formed within the range of 9.5% to 95%. For example, when the inner diameter of the ink containing tube is 5 mm, the outer diameter of the lid is preferably formed to 4.75 mm.

The material of the lid 6 is not particularly limited, but preferably includes plastic or rubber, and when it is made of such a material, the material itself is inexpensive and can be easily manufactured. Further, the shape of the lid body 6 is not particularly limited, and any shape such as a columnar shape or a conical columnar shape can be used as long as the above object can be achieved. The preferred shape of the lid is such that the cross-sectional shape on the front end side is smaller than the cross-sectional shape on the rear end, and a taper or step is provided from the rear end side to the front end side so that the cross-sectional area becomes smaller. . When using a lid having such a shape, FIG.
It is preferable to position it in the backflow preventive agent so that the surface 61 on the large cross-section side is the rear end side of the writing instrument and the surface 62 on the small cross-section side is the tip side of the writing instrument as shown in FIG.
As described above, when the cross section of the lid body is formed inside the backflow preventing agent 5 in a tapered shape or a step shape, the lid body covers the rear end portion of the backflow preventing agent and prevents the backflow preventing agent from flowing out. It can be prevented more reliably. In addition, the shape of the lid body may be such that a concave portion is provided as shown in FIG.
When formed in this way, it can be reliably positioned at the rear end of the backflow preventive agent during centrifugal separation, which will be described later, and the recess makes it easy to manufacture the lid and mount it on the ink containing tube.

It is preferable that the thickness of the lid 6 (the size in the longitudinal direction of the ink containing tube) is made shorter than the filling length of the backflow preventing agent so that the lid does not come into direct contact with the ink. . This is because the backflow preventive agent is present between the water-based gel ink and the lid, so that the ink can be reliably prevented from drying and the ink having a relatively low viscosity can be reliably prevented from leaking to the outside.

In the writing instrument 1 of the present invention, the pen tip portion 2,
As the ink storage tube 3 and the water-based gel ink 4, conventionally known ones can be used as they are. The anti-reflux agent 5 can be the same as the anti-reflux agent used in writing instruments using this type of aqueous gel ink, which has a very high viscosity.
Even a substance having a lower viscosity that could not be used in the past can be used because it has a structure in which a lid is provided at the rear end of the anti-reflux agent.

The backflow preventive agent 5 is used in a conventional writing tool using a water-based gel ink, and is advanced together with the ink in the direction of the pen tip to prevent evaporation of volatile components in the ink and to prevent ink from being impacted when the writing tool is dropped. Prevent the pillars from breaking,
The ink was used to prevent the ink from flowing backward toward the trailing edge, and one having a high viscosity and being incompatible with the aqueous gel ink was used. In the present invention, the anti-reflux agent 5 is
A high viscosity is not required as in the past. That is, in the present invention, it is sufficient that both the lid and the backflow preventive agent can prevent the ink from flowing back toward the rear end. Therefore, the anti-reflux agent used in the present invention is not required to have a high viscosity so long as it is incompatible with the water-based gel ink and has a certain degree of viscosity. As a result, the backflow preventing agent 5 can be selected in a wider range than in the past.

The anti-reflux agent 5 is, for example, liquid paraffin,
Mineral oil such as liquid paraffin, vegetable oil, fish oil, grease, petrolatum, polybutene, α-olefin oligomer, silicone grease, silicone oil, higher fatty acid ester, higher alcohol, polyester, petroleum, α-olefin oligomer, polyglycol, etc. alone or 2 The above mixture may be mentioned. The viscosity of the backflow preventive agent 5 may be appropriately selected in accordance with the inner diameter of the ink containing tube and the outer diameter of the lid so long as it does not leak from the gap between the ink containing tube and the lid. Further, the amount of the backflow preventing agent 5 may be any amount as long as it can function together with the lid body to prevent the backflow and the evaporation of the ink, and is compared with the amount of the backflow preventing agent of the conventional writing instrument of this kind. Can be significantly reduced.

The water-based gel ink used in the writing instrument of the present invention is a conventionally known composition comprising components such as water, an aqueous medium, a colorant, a viscosity modifier, and other additives. Examples of other additives include surfactants, preservatives, rust preventives, sequestering agents for metal ions, and the like. An example of the component composition of the aqueous gel ink is shown in Table 1 below.

[0018]

[Table 1]

As the above-mentioned aqueous medium, an organic compound miscible with water is used, and alcohols, glycol ethers, polar organic solvents and the like are used. Specifically, alcohols include monohydric alcohols such as ethanol and isopropyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, 1,3 propanediol, propylene glycol, 1,3 butylene glycol, 1,4 butanediol, Dihydric alcohols such as 2,3 butylene glycol, neopentyl glycol, hexylene glycol and thiodiglycol, glycerin, trimethylolethane, trimethylolpropane,
Examples thereof include polyhydric alcohols such as 3-methylpentane-1,3,5-triol, diglycerin, and sorbit.
Examples of the glycol ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monobutyl ether, and the polar organic solvent includes pyrrolidone, N-methyl- Examples include 2-pyrrolidone and dimethylformamide.

Examples of the above colorants include titanium oxide, carbon black, carmine 6B, CI PigmentRe
d, CI PigmentGreen7, CI PigmentBlue and other pigments, C.I.
I.AcidRed87, CIAcidRed92, CIAcidYellow28, C.I.
I.AcidBlue9, CIAcidViolet, CIAcidBlue7, CI
Acid dyes such as AcidOrange56, CIAcidBlack2, CIAcidRed18, CIDirectBlack19, CIDirectBlack38, C.I.
I.DirectBlack154, CIDirectOrange6, CIDirectYe
Direct dyes such as llow44, CIDirectYellow87, and CIDirectBlue71 are listed.

As the above-mentioned viscosity modifier, a thickener composed of a water-soluble polymer is used. Xanthan gum,
Examples thereof include polysaccharides such as carrageenan, locust bean gum, and guar gum, hydroxymethyl cellulose, hydroxyethyl cellulose, sodium polyacrylate, popar, and the like.

Other additives include sodium hydroxide, sodium carbonate, triethanolamine, etc. as a pH adjuster, anionic and nonionic surfactants as a surfactant, benzotriazole etc. as a rust inhibitor, and a preservative. As methyl-P-hydroxybenzoate, potassium sorbate, sodium pentachlorophenol,
E as a sequestering agent for sodium dehydroacetate, etc.
DTA etc. are mentioned.

In the writing instrument of the present invention, the pen tip portion 2 may be any of the known ball-point pen type with or without batting, a felt-tip pen, and the like.
In particular, the form of a water-based ballpoint pen having no batting is most suitable, and ink can be smoothly discharged and excellent in writability can be obtained.

In the writing instrument of the present invention, the ink containing tube 3
The one that has been conventionally used as this kind of ink storage tube can be used. For example, made of polypropylene or polyethylene, with an inner diameter of 1 to 8 mm and a length of 40 to 120
The thing of about mm is used.

In order to manufacture the writing instrument of the present invention, the ink containing tube is filled with the aqueous gel ink or the backflow preventive agent, and after defoaming by centrifugal separation, the lid 6 is inserted from the rear end open portion of the ink containing tube. It can be obtained. In addition, the lid 6 may be inserted before the centrifugal separation to be positioned at the rear end of the anti-reflux agent, and then subjected to the centrifugal separation to defoam. In this case, whether a material having a specific gravity lower than that of the backflow preventing agent is used as the material forming the lid, or whether the material has a concave cross-section as shown in FIG. Alternatively, it is preferable that the cover body is formed in a hollow shape to reduce the apparent specific gravity because the lid body can be reliably positioned at the rear end of the backflow preventing agent.

[0026]

As shown in FIG. 1 (d), when the aqueous gel ink 4 flows out using the writing instrument 1, the backflow preventive 5 and the lid 6 also move toward the pen tip 2. At this time, the writing instrument 1 of the present invention
Since the lid 5 advances while scraping off the backflow preventing agent 5 attached to the inner wall 37 of the ink containing tube, the backflow preventing agent 5 does not adhere to the inner wall 37 of the ink containing tube. 2 is a cross-sectional view of a writing instrument using an aqueous gel ink for explaining the action of the lid, (A) shows the writing instrument using the lid of the present invention, and (B) is a conventional lid. A writing instrument without using is shown. As shown in FIG. 2 (B), the writing instrument 30 in which only the backflow preventing agent is simply filled without using the conventional lid body has the interior of the backflow preventing agent 34 when the pen tip 31 is dropped upward. Will hang down. On the other hand, as shown in FIG. 2 (A), in the writing instrument 1 of the present invention, the backflow preventing agent 5 hangs down even if the writing instrument 1 is dropped with the pen tip portion 2 facing upward because of the lid 6. There is no such thing. Further, when the writing tool is used in a high temperature environment, for example, the conventional writing tool may hang down or flow out to the outside as in the case of dropping the writing tool as shown in FIG. 2 (B). However, in the case of the present invention, FIG.
Since the backflow preventing agent 5 is held by the lid 6 as shown in (A), there is no such fear.

[0027]

As described above, the writing instrument using the aqueous gel ink of the present invention has a structure in which the back end of the backflow preventive agent is provided with a lid having an outer diameter smaller than the inner diameter of the ink containing tube. As compared with a writing instrument in which only a backflow prevention agent is simply filled in the back of an aqueous gel ink without providing a lid, the backflow is caused as the ink is consumed and the ink and the backflow prevention agent move toward the pen tip. The lid moves together from the back of the inhibitor, and at that time, it moves in the direction of the pen tip while scraping off the backflow preventing agent adhering to the inner wall of the ink containing tube, so the backflow preventing agent adheres to the inner wall of the ink containing tube and decreases. Can be prevented and the amount of anti-reflux agent used can be reduced. As a result, it is possible to provide a writing instrument at a low cost by reducing the amount of expensive anti-reflux agent used as a raw material, and to increase the ink filling amount inside the ink containing tube, so that the same length of ink containing tube is used. Even if there is, the amount of writing will increase.

Further, when the amount of the backflow preventing agent used is reduced, the adhesive force between the backflow preventing agent and the inner wall of the ink containing tube becomes small, so that the ink flows out smoothly. Further, since the above-mentioned backflow preventing agent hardly adheres to the inner wall of the ink containing tube, the amount of the backflow preventing agent proceeds in the direction of the pen tip with a constant amount, so that the backflow preventing agent and the inner wall of the ink containing tube are separated from each other. The adhesive strength does not change, and the ink flow is constant from the beginning to the end of use, giving a writing instrument with a good writing feel.

The writing instrument of the present invention has a low viscosity as an anti-reflux agent because it performs the anti-reflux effect on both the anti-reflux agent and the lid as compared with the conventional writing instrument using a high-viscosity anti-reflux agent. Can be used, and the range of selection of materials that can be used as the anti-reflux agent is expanded. Furthermore, in the case of conventional writing instruments that consist only of anti-backflow agents and are not provided with lids, the vicinity of the center of the cross section of the ink containing tube farther from the inner wall of the ink containing tube of the anti-backflow agent is not sufficiently retained and the temperature rises due to changes in the operating environment In addition, there is a problem that the ink may hang down toward the rear end of the ink containing tube or pop out to the outside due to an impact when dropped, but in the present invention, there is no such fear.

[Brief description of drawings]

FIG. 1 shows an example of a writing instrument using an aqueous gel ink of the present invention, (a) is a cross-sectional view, (b) is an enlarged view of the vicinity of the rear end of an ink containing tube of a lid, (c) [Fig. 4] is a cross-sectional view taken along line CC of Fig. 6B, and Fig. 8D is a cross-sectional view showing a state after use.

FIG. 2 is a cross-sectional view of a writing instrument using an aqueous gel ink for explaining the action of the lid, (A) shows a writing instrument using the lid of the present invention, and (B) shows a conventional lid. Writing instruments not used are shown.

FIG. 3 is a diagram for explaining a writing instrument using a conventional water-based gel ink, (A) is a sectional view showing a state before use, and (A) is a sectional view showing a state after use. .

[Explanation of symbols]

 1 Writing implement using water-based gel ink 2 Pen tip part 3 Ink storage tube 4 Water-based gel ink 5 Backflow preventive agent 6 Lid

Claims (1)

[Claims] 1. A water-based gel ink, the viscosity of which is adjusted, and a backflow preventive agent, which has fluidity and prevents the ink from drying and backflowing, in an ink containing tube having a pen tip at the tip. A writing instrument using the aqueous gel ink, wherein a lid having an outer diameter smaller than the inner diameter of the ink containing tube is provided at the rear end of the backflow preventive agent.