JPH0460438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to dye-donor elements used in thermal transfer dyeing, and more particularly to the use of a specific slipping layer on the backside thereof to prevent chatter marks and tearing of the donor element during printing operations. Concerning what to do.

In recent years, thermal transfer systems have been developed to obtain prints from images obtained electronically from color video cameras. According to one method of obtaining such prints, the electronic image is first color separated with color filters. Each color-separated image is then converted into an electrical signal. These signals are then manipulated into cyan, magenta and yellow electrical signals. These signals are then sent to a thermal printer. To obtain a print, a cyan, magenta or yellow dye-donor member is placed face-to-face with a dye-receiver member. These two are then placed between the thermal print head and the platen roller. A line type thermal print head is used to apply heat from the back of the dye-donor sheet. The thermal print head has a number of heating elements and is heated in response to sequential cyan, magenta and yellow signals. This process is then repeated for the other two colors. A color hard copy corresponding to the original image seen on the screen is thus obtained.

US Pat. No. 4,567,113 relates to a slipping layer containing fatty acids and fatty alcohol derivatives. US Pat. No. 4,572,860 relates to a slipping layer made of urethane or vinyl chloride resin or higher fatty acid.

The use of dye-donor elements in thermal transfer printing is problematic because a thin support is required for effective thermal transfer. For example, when using a thin polyester film, heating during the printing operation will cause the film to soften and then stick to the thermal print head. For this,
Transport across the thermal head is intermittent rather than continuous. The transferred dye does not appear as a uniform area, but as a series of alternating bands (chatter marks).
Friction often occurs during printing to the extent that it tears the dye-donor member. It is desirable to eliminate such problems in order to obtain a commercially acceptable system.

A problem with many of the slipping layer materials that have been proposed for use in thermal transfer printing is that they do not always have sufficient performance.

It is an object of the present invention to provide a slipping layer material for dye-donor elements that does not stick or tear when passed through a thermal head.

These and other purposes essentially require a dye layer on one side and a number average molecular weight on the other side.
This is achieved according to the invention, comprising a dye-donor element for thermal transfer dyeing of dyes, comprising a support having a slipping layer of a lubricant of a fatty acid ester of polyethylene glycol or polyvinyl alcohol of 6000 or more.

The polyethylene glycol useful in the present invention having a number average molecular weight of 6000 or more can be any commercially available material, such as Carbowax 20M.
Polyethylene glycol (molecular weight 20,000) (Union Carbide) or Eastman 15415
Polyethylene glycol 8000 (molecular weight 7000~
9000) (Eastman Kodatsu Co.), may be used.

Any fatty acid ester of polyvinyl alcohol can be used in the present invention. For example, repeat unit: poly(vinyl octoate) with (R=
C ₇ H ₁₅ ), poly(vinyl pelargonate) (R=
C ₈ H ₁₇ ), poly(vinyl laurate) (R=
C ₁₁ H ₃₅ ) or poly(vinyl stearate) (R
= C ₁₇ H ₃₅ ) is used. In a preferred embodiment of the invention, the lubricating material is poly(vinyl stearate). This material is commercially available from Polysciences (No. 3169).

The lubricant used in the slipping layer of the present invention can be used in any amount effective for the intended purpose. Generally, good results are between 1 and
A coating weight in the range of 2000 mg/m ² is obtained.

Any dye that can be transferred to the dye-receiving layer by the action of heat can be used in the dye layer of the dye-donor element of this invention. Particularly good results were obtained with sublimable dyes such as: or any of the dyes described in U.S. Pat. No. 4,541,830. The above dyes can be used alone or in combination to obtain a single color. Dye is 0.05-1g/ ^m2
It can be used in a coating amount of 100% and is preferably hydrophobic. A dye barrier layer may be used in the dye-donor elements of the present invention to improve the concentration of transferred dye.

The dye in the dye-donor moiety is a polymeric binder, such as cellulose derivatives such as cellulose acetate hydrogen phthalate, cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose triacyl; polycarbonate; (styrene-acrylonitrile) copolymer, poly( sulfone) or poly(phenylene oxide). The binder can be used in a coverage of 0.1 to 5 g/m ² .

The dye layer of the dye-donor member may be coated onto the support or printed thereon by printing techniques such as gravure.

Any material that is dimensionally stable and capable of withstanding the heat of the thermal print head can be used as the support for the dye-donor member of this invention. Such materials include polyesters such as poly(ethylene terephthalate); polyamides; polycarbonates; glassine paper; capacitor paper; cellulose esters; fluoropolymers; polyethers; polyacetals; polyolefins; and polyimides. The support generally has a thickness of 2 to 30 μm. It may also be coated with a subbing layer if necessary.

Dye-receiving members for use with the dye-donor members of this invention typically consist of a support having a dye image-receiving layer thereon. For example, the support can be a transparent film such as poly(ethylene terephthalate), or a reflective film such as flash paper or white polyester (polyester mixed with white pigments).

The dye image-receiving layer may be made of, for example, polycarbonate, polyurethane, polyester, polyvinyl chloride, styrene-acrylonitrile copolymer,
Consists of poly(caprolactone) or mixtures thereof.

As mentioned above, the dye-donor member of the present invention comprises:
Used to form dye transfer images. Such methods consist of an imaging process in which a dye-donor member as described above is heated and a dye image is transferred to a dye-receiver member to form a transferred image.

The dye-donor elements of this invention may be used in sheet form or in continuous roll or ribbon form.
If a continuous roll or ribbon is used, it has only one dye on it or, as described in U.S. Pat. No. 4,541,830,
It has alternating regions of different dyes, such as sublimable cyan, magenta, yellow, black, etc. Accordingly, one, two, three or four colored members (or even more) are within the scope of the present invention.

In a preferred embodiment of the invention, the dye-donor member consists of a poly(ethylene terephthalate) support coated with sequentially repeating regions of cyan, magenta and yellow dye, and the above process steps are applied to each color. A three-color transfer image is obtained. Of course, when this process is performed only for a single color, a single color transfer image is obtained.

Thermal print heads that can be used to transfer dyes from the dye-donor elements of this invention are commercially available. For example, Fujitsu thermal head (FTP-
040MCS001), TDK Thermal Head F415 HH7
−1089 or ROHM Thermal Head KE 2008−
F3 can be used.

The thermal transfer dyeing combination for use in the present invention comprises (a) a dye-donor member as described above and (b) a dye-receiver member as described above, wherein the dye layer of the dye-donor member is a dye-donor member as described above. The dye-receiving member is in overlapping relationship with the dye-donor member in contact with the dye image-receiving layer of the receiver member.

The above-mentioned combination of these two members may be pre-assembled as an integral unit when a monochromatic image is to be obtained.
This can be done by temporarily gluing the two parts together at their ends. After the metastasis,
Peeling off the dye-receiving member reveals the transferred image.

When a three-color image is to be obtained, the above combination is formed in three cases while heat is applied by the thermal print head. After transferring the first dye, the member is peeled off. A second dye-donor member (or another area of the donor member with a different dye area) is then properly aligned with the dye-receiver member and the process is repeated. The third color is obtained in the same way.

EXAMPLES The following examples are presented to illustrate the invention.

Example 1 A magenta dye-donor member was prepared by coating a 6 μm poly(ethylene phthalate) support with the following layers in the order listed: (1) dye-barrier layer of gelatin nitrate ( In solvents of acetone, methanol and water, approx. 20:
gelatin, nitrocellulose and salicylic acid) (0.17 g/m ² ) and (2) 8% cyclohexanone in 2-butanone (0.22 g/m ² ) and hydrogen acetate in a weight ratio of 50:2. Dye layer containing cellulose phthalate (18-21% acetyl, 32-36% phthalyl) (0.39 g/ ^m2 ).

A slipping layer was coated on the back of the dye-donor member with the lubricant shown in Table 1 (0.86g/
^m2 ).

The dye-receiving member is 2.9 g/m ² Macrolon.
5705 Polycarbonate resin (Bayer),
Prepared by coating onto ICI Melinex 990 white polyester support using a solvent mixture of dichloromethane and trichloroethylene or chlorobenzene.

The dye side of each 0.75 inch (19 mm) wide dye-donor member strip was placed in contact with the dye image-receiving layer of the same width dye-receiver member. This combination was secured to the jaw of a stepper motor driven tensioner. The combined body has a diameter of 0.55 inch (14
mm) on top of a rubber roller, press a Fujitsu thermal head (FTP-040 MCS001) against the dye-strong solid material side of the combination with a spring with a force of 35 pounds (1.6Kg), and then press this with a spring on the rubber roller. pressed against.

The imaging electronics were activated and the tensioning device pulled the printhead and roller combination at 0.123 inches/second (31 mm/second). At the same time, the resistor in the thermal print head is heated from 0 to 4.5 msec in 0.5 msec increments.
A scale density test pattern was obtained. The voltage supplied to the print head was approximately 19V, which was approximately 1.75 Watts/
It meant dot. Estimated head temperature is 250-400℃
It was hot.

The passage of the combination through a thermal head was evaluated. If no tearing was observed, the combination was separated, the dye-donor was discarded, and the dye transferred to the dye-receiver was visually evaluated. The following data were obtained: Table 1 Lubricant performance Inventive poly(vinyl stearate) (Polyscience Seeds) G Carbo Wax 20M Poly(ethylene glycol) (molecular weight 20000) (Union Carbide)
G Eastman 15415 Polyethylene glycol
8000 (molecular weight 7000-9000) (Eastman Kodatsu) G Control Eastman 1305 Beeswax (Eastman Kodatsu) P Tone PCL-700 Polycaprolactone (Union Carbide) F Eastman 15414 Polyethylene glycol
1450 (Eastman Kodatsu) F Parafine Wax P21 (Fitsiya Scientific) T Eastman 1306 Carnauba wax (Eastman Kodatsu) P Hexacosane P Octacosane T Eicosane T Stearic acid F Tergitol 15-S-30 Polyethylene Blocked Polyethylene Glycol (Union Carbide) PE - Excellent Performance - Moves smoothly through the head and creates a uniform record.

G - Excellent Performance - Produces a homogeneous record although occasionally a little sticky when passing through the head.

F - Good performance - Occasionally sticky when passing through the head. The image has variations in density.

The performance of the P-head passage is poor and the image is homogeneous.

Tears when passing through T-head. Not evaluable.

The above data promotes smooth passage of the thermal head. Figure 2 illustrates the unique capabilities of the lubricant used in the slipping layer of the present invention. Control materials either tore or had good or poor performance.

Example 2 A dye-donor member was prepared with 0.32% of the cyan dye described above.
It was produced as in Example 1 except that g/m ² was used. A slipping layer was coated with a dye-donor member having the lubricant shown in Table 2 (0.11 g/m ² ).

A dye-receiving member was prepared as in Example 1.

1 inch (25 mm) wide of each dye-dye side of the donor member and the same width of dye-the dye image of the receiver member.
It was placed in contact with the receptor layer. This combination was secured to the jaw of a stepper motor-driven tensioner. Place the assembly on top of a 0.55 inch (14 mm) diameter rubber roller and place a TDK thermal head (No. L-133) on the dye-donor member side of the assembly.
A force of 8.0 pounds (3.6 Kg) was used to press it against a rubber roller.

The imaging electronics were activated and the tensioner pulled the printhead and roller combination at 0.123 inches/second (3.1 mm/second). At the same time, the resistor in the thermal print head was pulse heated from 0 to 8.3 msec to obtain a scale density test pattern. The voltage supplied to the print head was approximately 22V, which meant approximately 1.6 Watts/dot (13 millijoules/dot) for maximum power to a 0.1 mm ² area image.

Passage of the assembly through the thermal head was evaluated as in Example 1. If no tearing was observed, the assembly was separated, the dye-donor was discarded, and the dye transferred to the dye-receiver was visually evaluated. The following data were obtained: Table 2 Lubricant Performance Poly(vinyl octoate) G Poly(vinyl perylgonate) G Poly(vinyl laurate) (Scientific Polymer Products) G Poly(vinyl stearate) (Polysciences, Inc.) G None (Control) T The above data again shows that the lubricant used in the slitting pink layer of the present invention promotes smooth passage to the thermal head, in contrast to the torn control material. Demonstrates unique abilities.

As can be seen from the foregoing description, use of the slipping layer material of the present invention results in dye-donor elements that do not stick or tear when passed through a thermal head.

Claims (1)

[Claims] 1. A dye for thermal transfer dyeing consisting of a support having a dye layer on one side and a slipping layer on the other side.
In the donor member, the slipping layer has the formula A dye-donor element as defined above, characterized in that it consists of a lubricating substance of a fatty acid ester of polyvinyl alcohol having repeating units of (R is an alkyl group of at least 7 carbon atoms).