JPH0494964A - Core for thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To stabilize winding quality in slitting and to make carrying property in printing good by a method wherein a core on a supply side of a thermal transfer recording material is made of plastic material and hardness of a part or the whole of an inner wall is specified. CONSTITUTION:A core 3 is mainly constituted of a plastic material. The hardness of a part or the whole of its inner wall is 97 deg. or under (according to the measuring method of ASTM D 2240) and should preferably be 90 deg.-0 deg.. It can be manufactured, for instance, as follows. The title core for thermal transfer recording medium is obtained by a method in which sheets of resin, rubber and paper of 97 degree or under hardness or those made 97 degree or under hardness by applying additional agents such as plasticizer, softening agent, etc., to general resin and rubber are bonded to an inner wall of a generally plastic made core (cylindrically manufactured product by extrusion molding of polyvinyl chloride resin, ABS resin, etc., are cut or the like) by use of adhesives or a hot melt adhesion method, etc., on a method in which the solution obtained by dissolving or dispersing abovementioned resin and rubber in organic solvent or the like is applied by a spray method, a dipping method, etc., to be dried.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a supply-side core of a thermal transfer recording medium, and more specifically, the present invention relates to a supply-side core of a thermal transfer recording medium, and more specifically, a core in which a long ink ribbon used for barcode printers, video printers, facsimile machines, etc. is wound. The present invention relates to a core for a thermal transfer recording medium useful for.

[Conventional technology]

Thermal transfer recording methods have come to be used in many fields such as barcode printers, video printers, and facsimile machines because they have features such as low noise, low cost, maintenance free, small size and light weight.

Incidentally, as shown in FIG. 1, thermal transfer recording media generally have a structure in which an ink film 15 is wound around a core 3 on the supply side (feeding side). In many cases,
The ink film 15 has an ink coating portion 2 provided on a base material (resin film). The core 3 is made by cutting a tube made of paper spirally wound, or a tube made of polyvinyl chloride, acrylic-butadiene-styrene copolymer (ABS), etc. into a cylindrical shape by extraction molding to an arbitrary length. It was created. As shown in FIG. 2, the core 3 is normally held by the supply shaft 11 in the printer.

The shaft 11 is designed to rotate together with the core 3 during printing, and in addition, friction and springs are used to apply appropriate tension to the ink film 15 between the roll-shaped recording medium 12, the thermal head 13, and the platen 14. This creates a force that suppresses rotation.

A slip prevention plate 21 is attached to the feeding-side shaft 11 to prevent the core 3 from slipping (shifting in the rotational direction) (FIG. 4). If the core is made of paper (paper tube), the slip prevention plate 21 has a structure in which it bites into the inner wall of the core.

However, when the former type of plastic tube (made of polyvinyl chloride, ABS resin, etc.) is used for the core, the plastic tube is hard and the sliding friction resistance of the inner wall is small. However, there is a problem that slippage occurs in the rotational direction during printing, wrinkles, etc. occur, and proper printing cannot be performed.

However, in order to solve this problem, a notch 31 (FIG. 5) is provided at the end of the plastic core 32.

It is designed to mesh with a protrusion provided on the printer side to prevent slipping in the rotational direction. However, this method requires modification of the printer, and it is also necessary to provide notches that match the size and number of protrusions on the printer. This notch 31 cannot be formed during extrusion molding,
The process of cutting it off after that increases, which also causes high costs.

Most barcode printers currently on the market use a method that holds the thermal transfer recording medium by friction with the inner wall of the core, so the reality is that notch-type cores cannot be used to match these printers.

When the latter paper tube is used for the core, there are problems as shown below.

■As the paper tube expands and contracts due to changes in the environment (especially humidity),
If the water content in the paper tube is 6% by weight or more when the sheet is slit, if it is stored in low humidity during the winter, the outer diameter of the paper tube will become smaller, and only the paper tube will come out from the ink sheet roll (paper tube falling out).
Wrinkles occur during printing. For this reason, it is necessary to adjust the moisture content of the paper tube during slitting.

■Due to poor dimensional accuracy of paper tubes, friction with the slit shaft, spacer, etc. during slitting is not constant, leading to variations in slitting winding hardness and wrinkles.

■When making paper tubes, long paper tubes are cut to the required length, but at this time burrs are generated, which must be removed.

[Problem to be solved by the invention]

The present invention solves the above-mentioned problems and provides a core for a thermal transfer recording medium that can always produce high-quality images.

[Means to solve the problem]

The present invention relates to a supply side core of a thermal transfer recording medium, comprising (1)
The core is made of a plastic material, and the hardness of part or all of the inner wall is 97° or less (according to the ASTM D2240 measurement method), or (2)
The core is made of a plastic material and is characterized by having an uneven shape on part or all of the inner wall.

As a result of various studies on means for effectively preventing slippage of the ink sheet, the inventors of the present invention found that the above (1)
Alternatively, according to (2), it has been found that a core for ink sheets that has both the advantages of paper tubes and plastic tubes can be obtained. That is, according to the present invention, a core can be obtained that has good dimensional accuracy, has little dimensional change, and does not slip on the output shaft of a J general-purpose printer. Furthermore, thermal transfer recording media using this core can be easily manufactured in large quantities with uniform hardness without winding misalignment or wrinkles, and there are no wrinkles or meandering during printing, and there is no occurrence of line breakage or white spots in the image. It can also be prevented.

The present invention will be explained in more detail below.

The core (1) according to the present invention is mainly composed of a plastic material, and the hardness of a part or the entire inner wall is 97° (according to the ASTM 02240 measurement method).
The angle below is preferably 95° to 0°. This can be manufactured, for example, as follows.

Ordinary plastic core (PVC resin, AB
Resin, rubber,
A method of bonding thin sheets of paper or general resin/rubber with additives such as plasticizers and softeners to a hardness of 97 degrees or less using an adhesive or hot melt bonding method, or a method of bonding the above resin/rubber. It can be obtained by applying a solution dissolved or dispersed in an organic solvent or the like by a spraying method, dipping method, etc., and then drying it.

A resin that is glued or coated on the inner wall of a plastic core.
The film thickness of rubber, paper, etc. must be about 102 pa or more, preferably 150 pa or more. If the film thickness is thinner than 1021 Ja, the hardness is unlikely to fall below 97 degrees. There is no particular upper limit to the film thickness, but the condition is that the core can be set on the delivery shaft of the printer.

The area where the film is formed may be all or part of the inner wall of the core, but
It must be formed at least in a part of the range that contacts the slip prevention plate attached to the printer's delivery-side shaft. This film of resin, rubber, paper, etc. may be formed even on the outer wall or end surface (cut surface) of the plastic core.

Commercially available resins, rubbers, plasticizers, softeners, etc. can be used, and may be adjusted so that the hardness is 97 degrees or less by singly or by mixing or adding. These materials can be selected from the following, for example.

(Resin) Polyethylene (PE) Vinyl chloride resin (PVC) Polystyrene (PS) Polypropylene (PP) Methacrylic resin (PMMA) Urea-melamine resin (UF-MF) Phenolic resin (PE) Unsaturated polyester (UP) ABS resin (ABS ) Epoxy resin (EP) Polyacetal (POM) Nylon resin (nylon PA) Polycarbonate (PC) Polyethylene terephthalate (PET) Polybutylene terephthalate (PBT) Polyphenylene oxide (P
po, nonyl) polyphenylsulfide (pps) polysulfone (PSF) fluororesin (PTFE) diallyl phthalate resin (DAP) silicone resin (Si) polyimide (PI) bismaleimide triazine resin (BT) polyamideimide (FAI) polyamide bismaleimide (PABI) Olefin vinyl alcohol copolymer (GL resin) Polyoxybenzylene (Econol) Polyether sulfone (PESF) Polyarylate (PAR, U polymer) (rubber) Natural rubber (NR), synthetic natural rubber (IR), Butadiene rubber (BR), butadiene-styrene rubber (SBR),
Butidiene-acrylonitrile rubber (NBR), chloroprene rubber (CR), butyl rubber (IIR), thiocol, urethane rubber, silicon rubber, fluororubber, Hypalon, acrylic rubber (ABR) (Plasticizer) Phthalic acid derivative Tetrahydrophthalic acid derivative Azelaic acid Derivatives Maleic acid derivatives Trimellitic acid derivatives Itaconic acid derivatives Ricinoleic acid derivatives, other fatty acid derivatives Phosphoric acid derivatives Glycol derivatives Paraffin derivatives Polymerization plasticizers Isophthalic acid derivatives Adipic acid derivatives Sebacic acid derivatives Fumaric acid derivatives Citric acid derivatives Oleic acid derivatives Stearic acid Derivatives Sulfonic acid derivatives, other monoester plasticizers Glycerin derivatives Epoxy derivatives (softeners) Mineral oil-based softeners sub (factices) Vegetable oil-based softeners Fatty acids and fatty acid salts On the other hand, the core of the above (2) according to the present invention is It is constructed mainly of plastic material, and part or all of the inner wall has an uneven shape. This can be manufactured, for example, as follows.

■A method in which when extruding a plastic core, the mold is modified so that unevenness is created in the circumferential direction of the inner wall.

■A method of making scratches (recesses) on the inner wall of a regular plastic core using a cutting tool.

■A method of attaching plastic pieces to the inner wall of a regular plastic core.

There are other methods, but method (■) is low cost and suitable for mass production.

The depth of the recess is preferably 0.1 tumor or more. If it is shallower than 0.1 mm, the slip prevention plate of the printer's delivery-side shaft may not be caught, causing slippage.

The number of recesses is 1 to several dozen.

In order to maintain the roundness of the core, it is desirable that the recesses be located at uniform intervals in the circumferential direction of the inner wall of the core.
This is not the case when the core thickness is sufficient. Further, it is necessary that a recess exists at least at a position that contacts the slippage prevention plate.

〔Example〕

Here, both parts are based on weight.

Example 1 A large number of plastic tubes were produced by extrusion molding a vinyl chloride resin into a cylindrical tube having an inner diameter of 24.4 mm and cutting it into a length of 80 mm. A core having a thickness of approximately 500 cm, which was prepared by adding 10% plasticizer to low-density polyethylene resin, was adhered to the entire inner wall of the plastic tube using an adhesive.

Separately, a plate made from the above-mentioned polyethylene resin and plasticizer was attached to the same vinyl chloride resin flat plate using an adhesive.
The hardness was measured using ASTM D2240 (S-709) and found to be 93 degrees.

Next, an ink having the following composition was coated on one side of a PET film having a width of 1 m and a thickness of about 4.5 mm by gravure coating so that the thickness after drying was about 3.5 μs.

(Ink composition liquid) Carnauba wax 6 parts Paraffin wax (m, p, 70°C) 6 parts EV
A 1 part carbon black 2 parts toluene
85 parts Furthermore, the above-mentioned P
A heat-resistant layer (thickness after drying: approximately 0.03 tones) having the following composition was provided on the surface of the ET film opposite to the ink-coated surface.

(Heat-resistant layer coating liquid) Silicone resin 9.9 parts Crosslinking agent 0.1 part Toluene 99.0 parts The ink film thus obtained is slit into 80 mm width with a slitter and wound around the core by a length of 300111 mm. It was used as a thermal transfer recording medium.

Example 2 A tube having a cross section as shown in FIG. 3 was produced by extrusion molding using ABS resin, and cut into a length of 80 m++ to form a core. In addition, in Fig. 3, Q=32.0III
Il, do26.4+u+, n=25.4mm.

Next, the ink film produced in Example 1 was wound around this core in the same manner as in Example 1 to obtain a thermal transfer recording medium.

Comparative Example 1 A thermal transfer recording medium was obtained in the same manner as in Example 1 except that a general paper tube made of spirally wound paper was used as the core. The moisture content of this paper tube was 9% and the wall hardness was 95 degrees.

Comparative Example 2 A thermal transfer recording medium was obtained in the same manner as in Example 1, except that the core was a plastic tube processed into a cylindrical shape by extrusion molding using vinyl chloride resin. The wall hardness of this plastic tube was 100 degrees.

100 thermal transfer recording media were produced using each of these methods and evaluated for (1) image blanking, (2) core omission, (3) soft winding, and (4) blocking.

The results were as shown in Table-1.

Table 1 (Note 1) Image blanks are printed on mirror coated paper using a commercially available barcode printer (BCJ manufactured by Autonics) using 10 thermal transfer recording media. Use all 300m of ink sheet. At this time, the inner wall of the core and the printer's feeding side (supply side)
Observe the occurrence of white spots in the image due to wrinkles and meandering caused by slipping or misalignment with the shaft, and evaluate by the number of occurrences out of 10.

(Note 2) For core extraction, 10 pieces of each thermal transfer recording medium were removed at 25°C, 10% R11.
Leave it in an environment for 10 days. Thereafter, with the ink film roll fixed, a force of 1 kgf was applied to only the ends of the core in the length direction of the core. At this time, the number of cores that moved through the ink sheet film roll was counted.

(Note 3) Place 40 thermal transfer recording media each on a horizontally installed stainless steel plate, and place them on a stainless steel plate with a base of 10 CI.
A rectangular parallelepiped I x 10011 weight made of stainless steel weighing 4 kg is placed horizontally. At this time, the change in the outer diameter of the winding is In+m
Count the number of things there are.

(Note 4) Blocking 40 pieces of each thermal transfer recording medium were left in a constant temperature bath at 50°C for 72 hours. After that, the ink film 30+
1. Unwind all the layers and count the number of layers whose ink layer has been transferred (blocked) onto the heat-resistant layer due to hard winding.

〔Effect of the invention〕

Use of the core for thermal transfer recording media of the present invention brings about the following effects.

(1) Since the dimensional accuracy of the core is good and there is little dimensional change in the core due to environmental changes, the winding quality during slitting is stable.

(2) Since there is no slip on the printer's delivery-side shaft, the conveyance during printing is improved.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a thermal transfer recording medium. FIG. 2 is a schematic diagram of the ink film transport path within the printer. FIG. 3 shows a cross section of an example of a core for a thermal transfer recording medium according to the present invention. FIG. 4 is a perspective view and a side view of a device in which a slip prevention plate is attached to a feeding-side shaft. FIG. 5 is a perspective view of a conventional example in which a notch is provided at the end of the core. 1... Base material (resin film) 2... Ink coating section 3, core 11... Feeding side (supply side) core 12... Roll-shaped recording medium 13, Thermal head 14... Platen 15,... Ink film 16... Receiving paper 17... Receiving paper roll 18... Winding side shaft 21... Slip prevention 22... Mounting screw 31... Notch 32... Core patent applicant Rico Co., Ltd.

Claims (2)

[Claims] (1) A supply core of a thermal transfer recording medium, the core being made of a plastic material, and having a hardness of a part or the entire inner wall of 97° or less (according to the ASTM D2240 measurement method). Core for thermal transfer recording media. (2) A core for a thermal transfer recording medium, which is a supply side core for a thermal transfer recording medium, the core being made of a plastic material, and having an uneven shape on part or all of its inner wall.