JPH06238995A - Base fabric for ink ribbon - Google Patents

Abstract

PURPOSE:To provide an ink ribbon in which graphic spot does not occur and which has excellent durability of a fusion-bonded part of the base fabric. CONSTITUTION:Base fabric for an ink ribbon comprises blended yarns formed at least at one of warps and wefts for constituting the fabric of polyamide fiber and polyamide fiber having lower melting point or higher boiling water shrinkage factor than that of the previous fiber or both the lower melting point and the higher boiling water shrinkage factor than those of the previous fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ribbon base cloth used in an impact type printer.

[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. In particular, it has been earnestly desired to improve the durability of the ink ribbon fusion-bonded portion as the printer speed and impact have increased rapidly in recent years.

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, when this cassette type ink ribbon is applied to a printer for printing, there is a drawback that printing unevenness called a graphic unevenness is generated in which a bent portion of the ink ribbon is densely printed.

Particularly, in the recent 24-pin and 48-pin dot printers which are characterized by high print quality, the print unevenness is a serious problem, and improvement of the graphic unevenness is desired.

Techniques for identifying the texture of a woven fabric have been proposed as means for improving graphic unevenness in JP-A-3-34883, JP-A-3-79380, and JP-A-3-73378, respectively. In addition, a technique for specifying the density ratio of warp and weft after scouring and finishing set with raw machine is disclosed in JP
It is proposed by the publication No. 1-249484.

[0007]

[Problems to solve problems] However,
The technique proposed in Japanese Patent No. 57-13431 is a technique in which a low-melting polymer is inserted between high-melting-point polymers and fusion is performed, and it is limited to interlayer adhesion and fusion inside the layer is insufficient, Insufficient improvement in the durability of the fused part, and
Workability at the time of fusion was also poor, and there was a problem. Further, with the increase in printer speed and impact, there has been a demand for high durability of the ink ribbon fusion portion, but at present, these requirements have not been met.

On the other hand, the occurrence rate of the graphic unevenness varies depending on the viscosity of the ink, the ink adhesion rate, the filling rate of the ink ribbon accommodated in the cassette, and the like. Regarding the spots, the required level has not been reached, and there is a big problem at present.

An object of the present invention is to provide an ink ribbon which has good durability at the fused portion and is less likely to cause graphic unevenness.

[0010]

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 has a polyamide fiber (A) and has a lower melting point or a higher boiling water shrinkage ratio than the polyamide fiber (A), or both of them. It is characterized in that it is composed of a mixed fiber with the polyamide fiber (B) having the characteristics of.

[0011]

The present invention is characterized in that the base fabric for the ink ribbon is formed by the mixed yarn of fibers having different characteristics. That is,
When a mixed yarn of ordinary polyamide fibers and fibers having different melting points and different boiling water shrinkage ratios is used, the low-melting-point yarns are mixed in the high-melting-point yarns, so the adhesive strength of the entire fusion-bonded part In addition to that, because the fusion endurance is significantly improved, and fibers having different boiling water shrinkage ratios are mixed, after weaving,
It has been clarified that the yarn is rich in bulkiness due to a difference in shrinkage due to scouring and the like, the ink absorbing capacity is increased, and the graphic unevenness is also greatly improved. When a mixed fiber of ordinary polyamide fiber and fiber having only different melting points is used, only the durability of the fused portion is significantly improved. Further, it was clarified that when a mixed fiber of ordinary polyamide fibers and fibers having different boiling water shrinkages from each other is used, only graphic unevenness is significantly improved. The usual polyamide fibers (A) referred to in the present invention include nylon 46, nylon 66, nylon 6, nylon 610, nylon 1
The other polyamide-based fiber (B) has a low melting point and a high boiling water shrinkage ratio as the other polyamide-based fiber (B). A polymerized copolymer or the like can be used. As the low melting point fiber as the polyamide fiber (B), nylon having a lower melting point than the polyamide fiber (A), preferably 5 ° C. or higher, more preferably 10 to 120 ° C. lower than the above nylon is used. can do. For example, nylon 66 can be used as the polyamide fiber (A) and nylon 6 can be used as the other polyamide fiber (B). Furthermore, as a fiber having a high boiling water shrinkage ratio as the polyamide fiber (B),
A high-viscosity drawn yarn or the like having a high polymer viscosity can be used.

The method of mixing fibers may be either a method of mixing fibers at the stage of the spinning step or a method of mixing fibers at the post-processing step.

The mixed fiber ratio of the mixed fiber is to improve the durability of the fused portion,
Further, from the viewpoint of improving graphic unevenness, it is preferably 15 to 85%, more preferably 24 to 76%. 15-8
When it exceeds the range of 5%, not only the effect of improving the durability of the fused portion decreases but also the effect of improving the graphic unevenness tends to decrease.

Mixed fiber ratio (%) = weight of A / (weight of A +
Weight of B) × 100 A: Polyamide fiber B: Polyamide fiber having a lower melting point and / or higher boiling water shrinkage ratio than A, or both of them, Sulfuric acid relative to the polymer constituting the warp or weft The viscosity is
It is preferably 2.4 to 3.8 in terms of durability of the fused portion, but is not limited thereto. Further, the content of titanium oxide contained in the yarn is preferably 0.15% or less, but this is not particularly limited.

The denier of such a thread is generally 5 to 5.
It may be 150 denier. The single yarn denier that constitutes such a yarn is preferably 0.6 to 3.0 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 3.0 denier, the printing sharpness tends to deteriorate.

[0016] Usually, when a yarn without additional twist is used for the warp, the graphic unevenness is extremely bad, but when the mixed yarn composed of fibers having different boiling water shrinkage ratio of the present invention is used for the warp, the additional twist is added. Even if not done, the graphic unevenness is greatly improved, and therefore, since it is not twisted further, not only the cost is reduced, but also the performance as an ink ribbon is extremely good, and particularly, it is characterized by high print quality. It is suitable as an ink ribbon for recent 24-pin and 48-pin dot printers.

Both the warp yarn and the weft yarn may of course not be twisted, but may be twisted in the range of 150 to 700 T / m, more preferably 200 to 600 T / m. As the woven structure of the base fabric for the ink ribbon, plain weave, induction plain weave, twill weave, satin weave and the like are used.
It is not particularly limited to this. The woven fabric density of such a woven fabric may be such that the warp is preferably 130 to 600 yarns / in, more preferably 140 to 550 yarns / in, and the weft yarn is
Preferably 100 to 400 lines / in, more preferably 1
10 to 350 lines / in is good.

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, the base fabric for an ink ribbon according to the present invention has a low melting point fiber mixed with a high melting point fiber even if it is fused in a state of being impregnated with an oil-based ink. Melts uniformly and induces a fusing behavior between the single fibers, so that stable fusing can be achieved despite the presence of the oil-based ink. On the other hand, in the method of sandwiching and fusing the low melting point sheet in the fusion-bonding portion as in the prior art,
Although the fusing behavior occurs only on the fusing surface of the low melting point sheet, the other parts have almost no involvement in the fusing, so that they are more point-adhesive than the present invention, and the result is that the fusing part Greatly reflects on the durability of.

The ink ribbon base fabric of the present invention may be subjected to appropriate post-treatments 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 not only has no G spots, but also has excellent durability of the fused portion of the base fabric.

[0021]

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 fused part of base cloth) The prepared base cloth for ink ribbon is melt-cut to a width of 13 mm and once cut to a total length of 13 m with scissors. It was applied by weight% and then fused by an ultrasonic welder (M-8400 manufactured by Branson Co.). Seven fused portions were provided in the ink ribbon at substantially equal intervals to form an endless ink ribbon. did.

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 (ink absorption capacity) After the test base fabric was fused to 10 cm × 10 cm to form a test piece, this The weight (A) of the test piece is measured. The test piece is dipped in an oil-based ink and defoamed with a vacuum dryer so that the ink is well penetrated into the test piece.

Then, the ink on the surface of the test piece impregnated with the ink is removed, and the test piece is sandwiched between filter papers to remove excess ink through the mangle. Further, the filter paper is replaced and the excess ink is removed through the mangle twice, and then the weight (B) of the ink-containing ribbon is measured.

The ink absorption capacity (IK: g / m ² ) is calculated by the following equation.

IK = (BA) × 100 (Graphic spots) Ribbon is stored in a cassette for a 9-pin dot printer (M-1550 manufactured by Tokyo Electric Co., Ltd.), and the ink ribbon (length 10 m) prepared above is stored. The 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 × ×: Spots were formed extremely thick Examples 1 to 12 and Comparative Example 1 Fiber made of nylon 66 polymer having relative sulfuric acid viscosity of 2.85 and nylon 6 having relative sulfuric acid viscosity of 2.80
Copolymer of nylon and nylon 66 (weight ratio of nylon 6 and nylon 66: 85/15, melting point: 190 ° C)
The number of single fibers is 5/29, 8/26, 11/2, respectively, so that the mixed fiber ratio with the fibers
3, 14/20, 17/17, 20/14, 23/1
40 denier 34 that is 1, 26/8, and 29/5
Multifilament yarns (stretched yarns) of filaments were produced by a spinning mixed fiber method (Examples 1 to 10).

Further, a fiber made of nylon 66 polymer having a sulfuric acid relative viscosity of 2.85 and a sulfuric acid relative viscosity of 2.8.
A multifilament yarn (drawn yarn) of 40 denier 34 filaments with 17/17 single filaments was produced by the spinning mixed fiber method so that the fiber mixture ratio with the fiber made of nylon 6 polymer being 0 was 50/50. (Example 1
1).

Further, a conventional 40-denier 34-filament multifilament yarn consisting only of commonly used nylon 66 polymer was prepared.

As shown in Table 1, the yarns used for the warp of the woven fabric are those which are not additionally twisted and those which are 280 T /
As for the weft, a yarn not subjected to additional twisting was used (Comparative Examples 1 and 2). A woven fabric having a plain weave design was prepared using the warp and the weft prepared for each.
These woven fabrics were subjected to scouring and finish setting according to a usual method to prepare an ink ribbon base fabric shown in Table 1.

For these ink ribbon base fabrics, ink ribbons were prepared based on the test method for the fused portion durability of the base fabric, and the durability of the fused portion of each base fabric, the ink absorption capacity, and The graphic spots were measured, and the results are shown in Table 1.

[0032]

[Table 1] As is clear from Table 1, in Examples 1 to 10, the fused portion of the base fabric had good durability, large ink absorbing ability, and good graphic spots.

In Example 11, the ink absorbency and the graphic unevenness were not good, but the fused portion durability was good.

On the other hand, in Comparative Examples 1 and 2, durability of the fused portion of the base cloth was poor, ink absorbency and graphic unevenness were not good, and it was not practical.

[0035]

EFFECTS OF THE INVENTION The ink ribbon base fabric of the present invention is free from the occurrence of graphic spots, has good durability at the fused portion of the base fabric, and has the latest 24-pin and 48-pin features of high printing quality. It is suitable as an ink ribbon for a pin dot printer, and can provide an ink ribbon suitable for a high-impact high-speed printer, a high-copy printer, etc. having a strong impact.

Claims (7)

[Claims] 1. At least one of the warp yarn and the weft yarn is characterized by having a polyamide fiber (A) and having a lower melting point, a higher boiling water shrinkage ratio, or both than the polyamide fiber (A). A base fabric for an ink ribbon, which is composed of a mixed fiber with a polyamide fiber (B). 2. The base fabric for an ink ribbon according to claim 1, wherein the melting point of the polyamide fiber (B) is lower than that of the polyamide fiber (A) by 5 ° C. or more. 3. The ink ribbon base fabric according to claim 1, wherein the polyamide-based fiber (B) has a boiling water shrinkage ratio higher than that of the polyamide-based fiber (A) by 4% or more. 4. The base fabric for an ink ribbon according to claim 1, wherein the mixed fiber ratio represented by the following formula is 15 to 85%. Mixed fiber ratio (%) = A weight / (A weight + B weight) x
100 A: polyamide fiber B: polyamide fiber having a lower melting point, a higher boiling water shrinkage ratio, or both than A 5. The polyamide fiber (A) is nylon 66.
The polyamide-based fiber (B) having a lower melting point, a higher boiling water shrinkage ratio, or both than the fiber is made of nylon 6 or a copolymer of nylon 66 and nylon 6. The base fabric for an ink ribbon according to claim 1, wherein 6. The base fabric for an ink ribbon according to claim 1, wherein a yarn that is not additionally twisted is used as the warp yarn. 7. The ink ribbon base fabric according to claim 1, wherein the form of the ink ribbon is an endless ink ribbon having a fused portion.