JPH0745254B2 - Ink ribbon - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ink ribbon (hereinafter also referred to as an ink ribbon) used for a printer, particularly an impact type wire dot printer.

[Conventional technology]

2. Description of the Related Art In recent years, impact printers used for computer terminal devices and the like print at high speed on various media, and high quality printing and high speed printing are required. Since this impact printer stably processes a large amount of information, the print head is required to have high reliability.

In particular, it is important for the print wire to operate stably for a long period of time without causing wear of the print wire or damage to the ink ribbon.

On the other hand, due to the demand for high quality printing and high speed printing, wire dot printers in particular require finer wire weight and lighter weight, and the wire diameter is as thin as 0.2 mm, and the wire material has a greater specific gravity than cemented carbide. However, high-speed copper and the like having a smaller specific gravity have come to be used.

For this reason, wear on the tip of the wire is becoming more important than ever.

Usually, as an ink used for this kind of ink ribbon, oleic acid, vegetable oil, a vehicle such as mineral oil, a dye as a colorant, carbon black is added, and uniformly kneaded,
It is generally dispersed.

However, although carbon black is an important colorant without fading in this formulation, it has been found to have an adverse effect on wire wear.

As a means of improving this wire wear, there is a method of adding an antifriction material.
JP-A-59-86671 discloses the addition of molybdenum disulfide and molybdate lake, and JP-A-59-86671 discloses the addition of graphite, molybdenum disulfide and carbon fluoride.

(B) There is also a method of adding a thickener, which is disclosed in JP-A-61-297184.
In the publication, it is proposed to add an image thickener such as metallic soap, hydrogenated castor oil, aluminum chelate and organic bentonite.

(C) A method of replacing carbon black with an organic pigment having a lower hardness has been proposed. For example, JP 61-24
Japanese Patent No. 6083 proposes a ribbon whose colorant is an organic pigment.

Particularly, in JP-A-61-297184, additives which are considered as aluminum-based coupling agents such as aluminum chelate and aluminum alcoholate are used as thickeners. However, the idea of this patent is that the thickener additive forms a mesh-like structure, and the coloring material, vehicle and auxiliary agent are retained in the gaps of the mesh structure, and this mesh structure prevents mechanical external stress from the printing wire. When it is received, it is said to be destroyed / separated to produce a lubricating effect, and aluminum chelate and the like are added for the thickening agent and the lubricating effect. Therefore, vegetable oils such as castor oil are used as vehicles. Vegetable oils are polar high boiling liquid substances containing unsaturated fatty acids. For example, castor oil is ricinoleic acid,
It contains oleic acid and linoleic acid, and linseed oil contains unsaturated fatty acids oleic acid, linoleic acid and linolenic acid. Even if the same aluminum-based coupling agent is used as is apparent from the action of the present invention described later, oleic acid,
In a vehicle having a polar group such as castor oil, the aluminum-based coupling agent is desorbed from the surface of carbon black, and a sufficient effect cannot be obtained.

[Problems to be Solved by the Invention]

Of the above means for improving wire wear, (a)
(B) is still insufficient as a measure against wire wear, and the improved means (c) that mainly uses organic pigments instead of carbon black has very little wire wear, but it has light resistance of printing. However, it has a drawback that it cannot be used for official documents because it has poor solvent resistance.

An object of the present invention is to provide an ink ribbon which uses a coloring material containing carbon black and which has extremely little wire abrasion, by taking advantage of the excellent light resistance and chemical resistance of carbon black as a coloring agent.

[Means for Solving the Problems]

As a result of intensive studies conducted by the present inventors to solve the above problems, the insulation resistance of the ink is increased even if it contains carbon black, for example, if the resistance is 100 MΩ or more, wire abrasion is significantly reduced. The present invention was completed by finding the fact that

Here, in order to increase the insulation resistance of the ink, it is particularly effective to use a coloring material containing carbon black together with an aluminum coupling agent and a non-polar high boiling point liquid substance.

That is, the present invention provides (1) an ink ribbon obtained by impregnating a ribbon base material with an ink containing carbon black, wherein the insulation resistance of the ink is 100 MΩ or more.

(2) It is composed of a ribbon base material and an ink, and the ink contains a coloring agent containing carbon black, an aluminum-based coupling agent, and a non-polar high boiling point liquid substance as main components to increase the insulation resistance to 100 MΩ or more. It is an ink ribbon consisting of a different ink.

In the present invention, the insulation resistance of the ink is the resistance value when two electrodes are inserted into the ink layer at a distance of 2 mm so that the immersion depth is 7 mm, and the insulation resistance value between the two electrodes is measured.

In the present invention, a colorant containing carbon black is used as the colorant. This is because, as described above, carbon black is chemically stable, so it has strong light resistance and chemical resistance and can be used safely even in official documents. However, even if an appropriate organic pigment is used in combination as a complementary color. good. In addition, a small amount of additives such as wax and resin may be added to improve transferability to paper. The amount of carbon black added is 10 to 30% by weight based on the total weight of the ink composition, and a portion of the carbon black may be replaced with an organic pigment.

When printing with an impact printer using an ink ribbon coated with an ink containing carbon black, considering why wear of the printing wire occurs, carbon black is not pure carbon but hydrogen, oxygen, sulfur,
It contains various components such as ash, of which oxygen and hydrogen are the components that greatly affect the chemical properties of the surface of the carbon black particles. Hydrogen remained due to incomplete completion of the dehydrogenation reaction during the carbonization reaction of the raw material hydrocarbon, and oxygen was bonded to the surface of carbon black by contact with oxygen in the air after the carbon black was formed. It is a thing. Therefore, it may be considered that hydrogen atoms exist inside the carbon black particles, but the characteristic feature is that oxygen atoms are localized on the particle surface. It is said that the oxygen atom bonded to the surface of the particle exists in the form of an oxygen-containing functional group such as a phenol group, a quinone group, a carboxyl group and a lactone group. When the tip of the wire of the impact printer is in direct contact with the surface of the carbon black particles, even when the two electrodes are inserted into the ink layer and the insulation resistance is measured, the carbon black particles are separated from each other through the functional groups on the surface. It is considered that the insulation resistance becomes low due to the conduction of. It is presumed that in this state, the tip of the wire is oxidized by the action of these functional groups, and this oxide is chipped off due to the impact at the time of impact and wear progresses.

That is, wire wear is accelerated by corrosion of the metal surface.

Therefore, suppressing wire corrosion also reduces wire wear. In order to suppress the corrosion of the wire, it is considered that the functional group on the surface of the carbon black particles may be covered by some means so that the tip of the wire does not directly contact the surface of the carbon black.

In such a state, the electrode for measuring insulation resistance will not directly touch the surface of the carbon black particles, and it is presumed that the insulation resistance also increases. According to a test conducted by the inventors of the present invention, when the insulation resistance value measured at an interval of 2 mm and a depth of 7 mm in the ink layer is 100 MΩ or more, the wear of the wire is remarkably reduced.

In the present invention, an aluminum coupling agent is used together with a coloring material containing carbon black in order to increase the insulation resistance, but this is not added as a thickener.

In the present invention, the purpose of the aluminum-based coupling agent is to bind to the surface of the carbon black, inactivate the surface, and prevent oxidation of the wire material. Therefore, oleic acid together with aluminum coupling agent,
If a vehicle having a polar group such as castor oil is used, the aluminum-based coupling agent is released from the carbon black surface, and the effect of the present invention is not exhibited. That is, it is important to use a vehicle of a non-polar high boiling point liquid substance together. Further, a dye may be added in order to increase the coloring power, but in this case, a strong dye such as a basic dye is not preferable, and it is preferable to use an oil-soluble dye having a low polarity as much as possible.

There are many types of aluminum-based coupling agents centering on aluminum chelate and aluminum alcoholate, and any of them can be used effectively, but those having a pigment dispersing ability are preferable. Regarding the amount of addition, it is effective to add 5 parts by weight or more to 100 parts by weight of carbon black contained in the ink composition, but it is desirable to add 20 to 50 parts by weight to 100 parts by weight of carbon black. Is preferably added. Carbon black added
If the amount is less than 5 parts by weight relative to 100 parts by weight, the surface of the carbon black is inactive, and if the addition amount is too large, the movement of the ink becomes poor and the printing performance is adversely affected. The upper limit is preferably 30% by weight of the total amount of the product.

The non-polar high boiling point liquid substance which is an important vehicle in the present invention refers to mineral oil, liquid paraffin, ester oil and the like, and has polar groups such as hydroxyl group, carboxyl group, amino group and sulfone group in the molecular structure. Refers to those that do not include.

The addition amount as the non-polar high boiling point liquid substance is the remaining amount other than the addition amounts of the colorant and the aluminum-based coupling agent.

As a manufacturing method, each component of a colorant, an aluminum-based coupling agent, and a non-polar high boiling point liquid substance is uniformly mixed with a mixer, and the mixture is uniformly dispersed with a three-roll mill, and then nylon 6 or nylon 66. It is applied and impregnated on a ribbon base material made of polyamide fiber or polyester fiber. This ink ribbon is connected to a Mobius ring to form an endless ribbon.

[Action]

Wire wear is accelerated by corrosion of its metal surface. Therefore, if the corrosion of the wire is suppressed, the wear of the wire will be reduced. Therefore, it has been conceived to increase the insulation resistance of the ink impregnated in the ink ribbon in order to suppress the corrosion of the wire.

It is the aggregated carbon black and the ionically insoluble dye that play a role in carrying electricity in the ink. In the present invention, by using an aluminum-based coupling agent, the surface of the carbon black is made inactive to increase the insulation resistance of the ink, the corrosion of the wire is suppressed, and as a result, it is attempted to reduce the wear of the wire agent. Is.
At this time, if a vehicle having a polar group such as oleic acid or castor oil or a dye having a strong polarity such as a basic dye is used, the aluminum-based coupling agent is desorbed from the carbon black surface, resulting in a sufficient effect. Is presumed to be unobtainable.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1) 20% by weight of carbon black (MA-8 manufactured by Mitsubishi Kasei) 73% by weight of mineral oil (paraffin type) 7% by weight of aluminum coupling agent (aluminum chelate M manufactured by Kawaken Fine Chemicals Co., Ltd.) After mixing the ingredients evenly and dispersing with a triple roll, about 14g /
The coating amount was m ² .

This ink ribbon was prepared in a Mobius ring of 60 m, and a dot impact printer (Fujitsu MB27410) was used to continuously print 100 million strokes per wire, and the wear amount of the wire was measured.

The ink ribbon was replaced every 20 million strokes.

The light resistance was evaluated by irradiating the printed paper piece with ultraviolet rays from a carbon arc for 100 hours using a fade meter manufactured by Suga Test Instruments Co., Ltd.

Regarding chemical resistance, print paper pieces were prepared using purified water, castor oil, 10% hydrochloric acid, 10% acetic acid, 10% ammonia, 10% sodium carbonate, 1% sodium hypochlorite, 50% ethanol, benzyl alcohol, It was immersed in 13 kinds of chemicals such as phenyl glycol, dimethyl ether, carbon tetrachloride and benzene for evaluation.

As shown in Fig. 1, the insulation resistance is measured by measuring the diameter in the ink.
Copper wires of 1 mm were installed at intervals of 2 mm and a depth of immersion of 7 mm, and measurement was performed using a DM-1005 type insulation resistance meter manufactured by Sanwa Denki Keiki Co., Ltd.

(Example 2) 20% by weight of carbon black (MA-8) 35% by weight of ester oil (oleic acid ester) (manufactured by Unistar H381R NOF Corporation) 38% by weight of mineral oil (paraffin type) Aluminum coupling agent 7 wt% (Aluminum chelate M) The above components were prepared into an ink ribbon and evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Example 3) 20% by weight of carbon black (MA-8) 10% by weight of oil-soluble dye (Oil Black HBB manufactured by Orient Chemical Industry Co., Ltd.) 40% by weight of ester oil (oleate ester) Mineral oil (paraffin type) 23 wt% -Aluminum coupling agent 7 wt% (Aluminum chelate M) The above components were prepared in the same manner as in Example 1 and evaluated. The results are shown in Table 1.

(Example 4) 20% by weight of carbon black (MA-8) 5% by weight of organic pigment (Alkali Blue Orient Chemical Co., Ltd.) 68% by weight of mineral oil (paraffin type) 7% by weight of aluminum coupling agent ( Aluminum alcoholate AMD Kawaken Fine Chemicals Co., Ltd.) The above components were prepared into an ink ribbon in the same manner as in Example 1 and evaluated. The results are shown in Table 1.

(Comparative Example 1) 20% by weight of carbon black (MA-8) 80% by weight of mineral oil (paraffinic) The above components were prepared in the same manner as in Example 1 and evaluated. The results are shown in Table 1.

(Comparative Example 2) 20% by weight of carbon black (MA-8) 10% by weight of basic dye (manufactured by Nigrosine Base EX Orient Chemical Co., Ltd.) 20% by weight of oleic acid (manufactured by LUNAC OP Kao) ・ Ester oil (Oleic acid ester) 20% by weight Mineral oil (paraffinic) 23% by weight Aluminum coupling agent 7% by weight (Aluminum chelate AL-M) The above components were prepared into an ink ribbon in the same manner as in Example 1, evaluated. The results are shown in Table 1.

(Comparative Example 3) 10% by weight of carbon black (MA-8) 10% by weight of basic dye (manufactured by Nigrosine Base EX Orient Chemical Co., Ltd.) 35% by weight of oleic acid (manufactured by LUNAC OP Kao) ・ Sorbitan trio Rate 15 wt% (Nonion OP-85R manufactured by NOF CORPORATION) Mineral oil (paraffinic) 30 wt% The above components were prepared into an ink ribbon in the same manner as in Example 1 and evaluated. The results are shown in Table 1.

(Comparative Example 4) (When molybdenum disulfide is added to Comparative Example 3 as an antifriction material) 5 parts by weight of molybdenum disulfide was added to 100 parts by weight of the ink prepared in Comparative Example 3, and Example 1 was further added. An ink ribbon was prepared and evaluated in the same manner as in.

(Comparative Example 5) (When lithium stearate was added as a thickener to Comparative Example 3) 5 parts by weight of lithium stearate was added to 100 parts by weight of the ink prepared in Comparative Example 3, and Example 1 was further added. An ink ribbon was prepared and evaluated in the same manner as in.

(Comparative Example 6) (When carbon black was replaced with organic pigment in Comparative Example 3) Organic pigment aniline black 5% by weight Copper phthalocyanine blue 3% by weight Alkaline blue 2% by weight Basic dye (Nigrosine base EX) 10 % By weight Oleic acid (Lunack O-P) 35% by weight Sorbitan trioleate 15% by weight (Nonion OP-85R) Mineral oil (paraffinic) 30% by weight The above components were applied to the ink ribbon as in Example 1. Prepared and evaluated. The results are shown in Table 1.

(Comparative Example 7) (When 35 wt% of the mineral oil of Example 1 is replaced with oleic acid) ・ Carbon black (MA-8) 20 wt% ・ Mineral oil (paraffinic) 38 wt% ・ Aluminum coupling Agent 7% by weight (aluminum chelate AL-M) -oleic acid 35% by weight The above components were uniformly mixed, then dispersed by a three-roll mill, and uniformly stirred. The ink was prepared and evaluated as in Example 1. The results are shown in Table 1.

The ink obtained by simply dispersing carbon black in mineral oil as in Comparative Example 1 has an insulation resistance of 30 MΩ and a wire wear amount of 45 μm.

Further, in Comparative Example 3 in which the conventional oleic acid, carbon black, and basic dye were blended, the wire wear amount was as large as 32 μm, and even if the anti-friction material and the thickener were added, it was clear in Comparative Examples 4 and 5. As described above, the wire wear amount is reduced to 15 to 16 μm by half, but it is not sufficient.

In Comparative Example 6, since oleic acid and a basic dye are used, the insulation resistance is not so large as 50 MΩ, but since a low hardness organic pigment is used instead of hard carbon black, the wire wear amount is 2 μm. However, since the colorants are only organic pigments and dyes, they have poor light resistance and chemical resistance and are not suitable for official documents.

On the other hand, in the present invention, as is clear from Examples 1 to 4, the insulation resistance is 100 MΩ or more, and the wire wear amount is 2 μm, which is very small. Moreover, since carbon black is used as a coloring agent, it has excellent light resistance and chemical resistance. However, even if an aluminum-based coupling agent is used as in Comparative Examples 2 and 7, the use of a polar vehicle such as oleic acid or a basic dye does not sufficiently reduce the amount of wire wear.

〔The invention's effect〕

In the present invention, by increasing the insulation resistance of the ink to 100 MΩ or more, while using a carbon black excellent in coloring stability, and its wire wear resistance is reduced to an extremely low level by suppressing corrosion wear in particular. Therefore, it is compatible with the high quality and high speed printing of impact printers and improves the reliability of the print head.

Further, in the present invention, by using a coloring agent containing carbon black and an aluminum-based coupling agent and a non-polar high boiling point liquid substance in combination, while using carbon black excellent in coloring stability while increasing the insulation resistance of the ink, The wire abrasion resistance could be made extremely low.

[Brief description of drawings]

FIG. 1 is a diagram showing a method for measuring the insulation resistance of the ink layer in the present invention.

Claims (2)

[Claims] 1. An ink ribbon comprising a ribbon base material impregnated with an ink containing carbon black, wherein the ink has an insulation resistance of 100 MΩ or more. 2. A ribbon base material and an ink, wherein the ink contains a colorant containing carbon black, an aluminum coupling agent and a non-polar high boiling point liquid substance as main components, so that the insulation resistance is 100 MΩ or more. Ink ribbon made of highly enhanced ink.