JPH08258383A - Base fabric for ink ribbon and ink ribbon - Google Patents

Abstract

PURPOSE: To further improve durability and sharpness of a printing chracteristic, durability of a fusion weld part, and improve effect of graphic spots by a method wherein at least either yarn of a warp or a weft constituting a base fabric is composed of a composite fiber in which a plurality of polymers having melting point differences are eccentrically combined. CONSTITUTION: A base fabric is composed of a fiber which is composed of a composite fiber of a plurality of polymers having a fusion weld temperature difference in a single fiber unit and in which at least one kind of a plurality of polymers having melting point differences is eccentric. A core-sheath composite composed of a low melting point polymer for a surface layer part (sheath) and high melting point polymer for an inner layer (core) of single fiber, or a bimetal composite, fiber composed of high melting point polymer and low melting point polymer is used for at least either yarn of the warp or the weft to constitute the base fabric. For the base fabric, all the fusion weld part containing a fusion weld surface participates in adhesive strength thereby, and durability of the fusion weld part is improved. The base fabric is eccentrically compounded to develop fine rolled up shrinkage, its ink-absorbing capacity is increased, and graphic spots are also improved.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is an ink ribbon, particularly an ink ribbon used for impact type printers, which has printing characteristics excellent in durability and sharpness, and further has durability and graphic characteristics of a fused portion. The present invention relates to an ink ribbon base fabric and an ink ribbon having excellent spots.

[0002]

2. Description of the Related Art Recently, ink ribbons used in impact type printers have decreased in conventional spool type, and long tape-shaped ink ribbons are folded and stored in a cassette, and both ends of the ink ribbons are ultrasonically welded. There is an increasing number of cassette-type cassettes that have an endless fused portion that is fused (bonded). Normal,
When printing, the ink ribbon is impacted by the head pin of the printer and gradually destroyed, but the above-mentioned fused part is less durable than the normal base cloth part, and the life of the fused part is longer than that of the ink ribbon. There is a strong demand for improving the durability of the fused portion of the ink ribbon because the life of the ink ribbon is affected. As described above, it has been earnestly desired to improve the durability of the ink ribbon fusion-bonded portion due to the recent rapid increase in speed and impact of the printer.

As a means for improving the durability of the fused portion, a technique of inserting a thermoplastic synthetic resin having a melting point lower than that of the base cloth between the two ink ribbons to be fused and fusing is known.
No. 13431 is proposed. Further, in Japanese Patent Application No. 5-513949, we propose a base fabric for an ink ribbon, which is composed of a core-sheath composite fiber having a polyamide polymer as a core and a polyamide polymer having a lower melting point than the polyamide polymer as a sheath. ing.

On the other hand, in the cassette type printer, since the ink ribbon is folded and stored, there is a drawback that printing unevenness, which is referred to as graphic unevenness, in which the bent portion is darkly printed occurs. As a means of reducing the graphic unevenness, a technique of specifying the density ratio of the warp and the weft,
It is proposed by Japanese Patent Laid-Open No. 1-249484. A technique for disturbing the arrangement of single fibers by high-pressure fluid treatment has been proposed by Japanese Patent Laid-Open No. 3-281277.

[0005]

[Problems to be Solved by the Invention] However, as a means for improving the durability of the fused portion, a thermoplastic synthetic resin having a lower melting point than the base cloth is inserted between the two ink ribbons to be fused. In the technique, the ink ribbon to be fused is impregnated with ink, so that the fusion between the polymers having different melting points is insufficient, the improvement of the durability of the fused portion is not sufficient, and Workability at the time of wearing was poor, and there was a problem. A base fabric for an ink ribbon, which is composed of a core-sheath composite yarn having a polyamide polymer as a core and a polyamide polymer having a melting point lower than that of the polyamide polymer as a sheath, is a technique for improving the durability of the fused portion. Has a large effect, but has no effect of reducing the graphic spots.

On the other hand, as a means for reducing the graphic unevenness, the technique of specifying the density ratio of the warp and the weft and the technique of disturbing the arrangement of the single fibers by the high-pressure fluid treatment are effective, but the durability of the fused portion is improved. The object of the present invention, which had no effect as a technique, is to provide an ink ribbon, particularly an ink ribbon used in an impact type printer, which has excellent printing characteristics in durability and sharpness, and further has a fused portion. The present invention provides a base fabric for an ink ribbon and an ink ribbon which have excellent durability and a large effect of improving graphic unevenness.

[0007]

The present invention employs the following means in order to achieve such an object. That is, in the base fabric for an ink ribbon of the present invention, at least one of the warp yarn and the weft yarn constituting the base fabric is composed of a composite fiber in which a plurality of polymers having different melting points are eccentrically combined. The ink ribbon of the present invention is characterized by using the ink ribbon as a base fabric.

[0008]

The present invention provides a base fabric for an ink ribbon, which is composed of a composite fiber of a plurality of polymers having a fusion temperature difference in a single fiber unit and is eccentric with at least one of a plurality of polymers having a different melting point. It is characterized by the points formed. That is, a core-sheath composite fiber in which the inner layer (core) of the single fiber is composed of a high melting point polymer and the surface layer part (sheath) is composed of a low melting point polymer,
Or, the base fabric woven by using the bimetallic composite fiber composed of the high melting point polymer and the low melting point polymer for at least one of the warp yarn and the weft yarn, the whole fusion-bonded portion including the fusion-bonded surface of the base fabric has an adhesive force. It contributes to the drastic improvement in the durability of the fused part, and at the same time, the fine crimps due to the eccentric compounding make the yarn rich in bulkiness, increase the ink absorption capacity, and greatly improve the graphic unevenness. It is the investigation of each improvement. We have found that by using a core-sheath composite fiber composed of two polymers having different melting points, the durability of the fused portion is improved, but the polymer having a different melting point has a different shrinkage ratio, By making this eccentric, it has been clarified that fine crimps are expressed. As the polymer used in the present invention, a polyester-based polymer can be used, but it is preferable to use a polyamide-based polymer for both the high-melting point polymer and the low-melting point polymer from the viewpoint of various properties as a base fabric for an ink ribbon. Polyamide-based polymers include nylon 46 and nylon 6
As the amide raw material of 6, nylon 6, nylon 610, nylon 11 and these polyamides, a copolymer obtained by copolymerizing one or more kinds of different amide raw materials can be used. Further, as the polymer constituting the eccentrically composited conjugate fiber, it is preferable to selectively combine, from the above-mentioned polyamides, those having a melting point difference of 5 ° C. or more, more preferably 10 ° C. or more and a large shrinkage ratio difference. The eccentrically composite conjugate fiber in the present invention is composed of a combination of a plurality of polymers, and usually a combination of two kinds of polymers can sufficiently fulfill the purpose. In addition, the composite ratio of the low melting point polymer and the high melting point polymer is 5 to 95% of the total weight of the low melting point polymer and the high melting point polymer from the viewpoint of improving the durability of the fused portion and improving the unevenness of graphics. It is preferably, and more preferably 10 to 80%. If it exceeds the range of 5 to 95%, the effect of improving the durability of the fused portion decreases and the effect of improving graphic unevenness also decreases.

In the present invention, from the viewpoint of improving the durability of the fused portion and improving the unevenness of the graphic, it is composed of a composite fiber in which a low melting point polymer and a high melting point polymer are eccentrically combined, and the inner layer (core) is used as the composite fiber. High-melting point polymer, core-sheath composite fiber whose surface layer (sheath) is composed of low-melting point polymer,
Alternatively, a bimetal composite fiber composed of a high melting point polymer and a low melting point polymer may be mentioned. The eccentricity of the core polymer in the core-sheath composite fiber varies depending on the composite ratio of the high melting point polymer and the low melting point polymer, but is preferably 5% or more, and more preferably 10% or more. When the eccentricity is less than 5%, the effect of improving the durability of the fused portion can be obtained, but the effect of improving the graphic unevenness is small, which is not preferable. The eccentricity in the present invention indicates the position of the center of the core polymer in the conjugate fiber when the center of the conjugate fiber is 0% and the surface is 100%.

The polymer constituting the warp or weft has a relative sulfuric acid viscosity of preferably 2.4 to 3.8 from the viewpoint of the durability of the fused portion, and a polymer in this viscosity range has a low melting point and a high melting point. It constitutes a melting point polymer. The content of titanium oxide contained in the yarn is preferably 0.15% or less, but is not particularly limited to this.

The denier of the warp or weft composed of such composite fibers may be 5 to 150 denier which is generally used. Further, the single yarn denier that constitutes such a composite fiber is preferably 0.6 to 5.0 denier that is generally used in order to form a thin base fabric. When the single yarn denier is less than 0.6 denier, the durability of the base fabric portion tends to decrease, and when the single yarn denier exceeds 5.0 denier, the printing sharpness tends to deteriorate.

[0012] Usually, when the warp which is not additionally twisted is used, the graphic unevenness is extremely bad. However, when the warp made of the eccentrically composited composite fiber of the present invention is used, the graphic unevenness is significantly increased without additional twisting. The improved 24-pin and 48-pin ink ribbons for dot printers are not only cost-effective because they are improved, and therefore they do not have additional twisting, and the performance as an ink ribbon is extremely good. Is suitable as

From the viewpoint of cost, it is preferable that both the warp and the weft are non-twisted, but if necessary 150 to 7
Additional twisting may be performed within the range of 00 T / m. The fabric structure of the ink ribbon base fabric includes plain weave, induction plain weave, twill weave,
And satin weave and the like are used, but not limited thereto. The woven fabric density of such a woven fabric is preferably 130 to 600 yarns / in, more preferably 140 warps.
~ 550 yarns / in, and the weft yarn is preferably 100-4.
00 lines / in, more preferably 110 to 350 lines / in.

The ink ribbon base fabric thus obtained is
After being woven, the usual scouring and finishing sets are applied.
Preferably, it is scoured by liquid scouring and 160 ° C with a pin tenter.
It is recommended to finish-set in the range of ~ 240 ° C. Then, an appropriate amount of an ink material such as an oil-based ink is attached (impregnated) to the base cloth, and then fused to form an endless ink ribbon. Such fusing is performed by using ultrasonic welders on both ends of the ink ribbon base fabric.

As described above, in the ink ribbon base fabric of the present invention, even if the ink is impregnated in the state of being impregnated with the oil-based ink, the fusion component contained in the single fiber unit is melted and the single fiber is fused. Since the adhesion behavior is induced, stable fusion can be achieved despite the presence of the oil-based ink. On the other hand, in the method of sandwiching the low-melting point sheet between the fusion-bonding portions as in the prior art and causing the fusion-bonding, the fusion-bonding behavior occurs only at the fusion-bonding surface of the low-melting-point sheet, but the other portions are not fused to each other. Since it is hardly involved, it becomes point-adhesive as compared with the present invention,
The result greatly reflects the durability of the fused portion.

The ink ribbon base fabric of the present invention may be subjected to a suitable post-treatment such as high-pressure fluid treatment, plasma treatment, surfactant treatment, and resin treatment. The ink ribbon formed by using the thus-obtained base fabric for an ink ribbon of the present invention has good durability of the fused portion of the base fabric and is also excellent in graphic unevenness.

[0017]

EXAMPLES The present invention will be described in detail below with reference to examples. The evaluation method used in the present invention is as follows. ◎ [Durability of base fabric fused part] The prepared base fabric for ink ribbon is melt-cut to a width of 13 mm and once cut to a total length of 13 m with scissors, and then an oil-based ink is applied to these base fabrics based on the weight of the base fabric. 22 wt% was applied and then fused by an ultrasonic welder (M-8400 manufactured by Branson Co., Ltd.). Seven fused portions were provided in the ink ribbon at substantially equal intervals to form an endless ink ribbon. It was made.

The ink ribbon is housed in a cassette for a 24-pin dot printer (UP-130K manufactured by Epson), the cassette is set in the printer, and alphabets,
And numbers were printed, the number of prints when a pinhole was generated in the fused portion was read, and the average value was used as the durability of the fused portion of the base fabric. ◎: 1.11 million characters or more ○: 91 to 1.1 million characters △: 71 to 900,000 characters ×: 700,000 characters or less [Graphic spots] A ribbon for a 9-pin dot printer (M-1550 manufactured by Tokyo Denki Co., Ltd.) (10 m in length) was stored, this cassette was set in the above printer, solid printing was performed, and the state of graphic generation was visually evaluated. The evaluation criteria are as follows.

◎: No spots were generated at all ○: Little spots were formed Δ: Thin spots were formed ×: Thick spots were formed xx: Large spots were generated Examples 1 to 12 and Comparative Example 1, 2 Eccentric core / sheath type composite fiber having nylon 66 polymer having a sulfuric acid relative viscosity of 2.85 (melting point 253 ° C.) as a core and nylon 6 polymer having a sulfuric acid relative viscosity of 2.80 (melting point 217 ° C.) as a sheath The polymer weight ratio of the core to the sheath is 95/5, 90/10, 70/30, 50/50, 2
Multifilament yarns of 40 denier 34 filaments with eccentricity of 0/80 and 10/90, respectively, shown in Table 1 were prepared (Examples 1 to 7).

Further, the same nylon 66 polymer as the core and nylon 6 polymer as the sheath as described above are used, and a normal core / sheath type composite fiber having an eccentricity of 0% with a polymer weight ratio of the core to the sheath of 50/50 is used. A 40-denier 34-filament multifilament yarn was prepared (Comparative Example 1).

Further, regarding a bimetallic composite fiber comprising a nylon 66 polymer (melting point 253 ° C.) having a sulfuric acid relative viscosity of 2.85 and a nylon 6 polymer (melting point 217 ° C.) having a sulfuric acid relative viscosity of 2.80, nylon 6
The weight ratio of 6 polymer to nylon 6 polymer is 95/5,
Multifilament yarns of 40 denier 34 filaments of 90/10, 80/20, 50/50, and 10/90 were prepared (Examples 8 to 12).

Further, an ordinary multi-filament yarn of 40 denier 34 filaments made only of commonly used nylon 66 polymer was prepared (Comparative Example 2).

Using these yarns as warps and wefts, a woven fabric having a plain weave design with a warp density of 203 yarns / inch and a weft yarn density of 120 yarns / inch was prepared. Next, these woven fabrics were scoured and finish-set by a usual method to prepare an ink ribbon base fabric shown in Table 1.

With respect to these base fabrics for ink ribbons, ink ribbons were prepared based on the test method for the fused portion durability of the base fabric and the test method for graphic unevenness, and the durability of the fused portion of each of the base fabrics. And the graphic spots were measured, and the results are shown in Table 1.

[Table 1] As is clear from Table 1, in Examples 1 to 12, the durability and graphic unevenness of the fused portion of the base fabric were good.

On the other hand, in Comparative Example 1, the fused portion of the base cloth had good durability, but the graphic unevenness was poor. In Comparative Example 2, the durability of the fused portion and the unevenness of graphics were poor.

[0026]

INDUSTRIAL APPLICABILITY The ink ribbon base fabric of the present invention has excellent durability and graphic unevenness at the fused portion of the base fabric and is characterized by high print quality in recent years, such as 24-pin and 48-pin dot printers. An ink ribbon suitable as an ink ribbon for use in high-speed printers, high-copy printers, and the like having a strong impact can be provided.

Claims (8)

[Claims] 1. An ink ribbon, characterized in that at least one of the warp yarn and the weft yarn constituting the base fabric is composed of a composite fiber in which a plurality of polymers having different melting points are eccentrically combined. Base cloth. 2. The ink ribbon base fabric according to claim 1, wherein the melting point difference of the polymers constituting the conjugate fiber is 5 ° C. or more. 3. The base fabric for an ink ribbon according to claim 1, wherein the conjugate fiber has a conjugate ratio represented by the following formula in a range of 5 to 95%. Composite ratio (%) = (weight of low melting point polymer) / (weight of high melting point polymer + weight of low melting point polymer) × 100 4. The ink ribbon base fabric according to claim 1, wherein the conjugate fiber has an eccentricity of 5% or more. 5. The ink ribbon base fabric according to claim 1, wherein the conjugate fiber has a core-sheath type or a bimetal type structure. 6. The base fabric for an ink ribbon according to claim 1, wherein the conjugate fiber is composed of a polyamide polymer. 7. An ink ribbon using the ink ribbon according to claim 1 as a base fabric. 8. The ink ribbon according to claim 7, wherein the shape of the ink ribbon is an endless ink ribbon having a fused portion.