JPS61139489A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To prevent the staining of the ground of a thermal transfer recording medium by providing a heat-meltable ink layer containing a colorant and a binder as main components to be almost thermally transferred by one-time operation and 0.01-5wt% silicon oil on a supporter. CONSTITUTION:A heat-meltable ink layer containing a colorant and a binder (e.g., vinyl acetate-ethylene coplymer, polyvinyl acetate, etc.) as main components to be almost thermally transferred by one-time operation and 0.01-5wt% silicon oil is provided ona supporter to form a thermal transfer recording medium. As the supporter, a polyestrer film (e.g., of polyethylene terephthalate), cellophane film, condenser paper, etc., may be used. The colorant used includes, besides carbon black, dis-azo pigments, phthalocyanine pigments, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a thermal transfer recording medium used in printers, facsimile machines, copying machines, and the like.

A conventional thermal transfer recording medium has a heat-sensitive transfer layer on a support that is transferred by heat, and this heat-sensitive transfer layer is made by adding a softening agent such as oil to pigment and wax. Mineral oil (Japanese Unexamined Patent Publication No. 59-2469
Publication No. 3, JP-A-59-81185, JP-A-59-Sho.
-33175, etc.), vegetable oil, and a surfactant (see JP-A-59-81185) are known.

However, when oil or the like is added to the thermal transfer ink layer, the transfer start temperature is lowered and there is a problem that background smearing is likely to occur.

Further, it has been proposed in Japanese Patent Application Laid-Open No. 58-101 to provide a heat-melting ink layer containing an oil lubricant such as silicone oil on thin paper.
This is known from Japanese Patent No. 095, but when the support is thin paper, there is a drawback that scumming is likely to occur.

1-Ichie The object of the present invention is to prevent the occurrence of scumming on a thermal transfer recording medium having a heat-melting ink layer that is thermally transferred in most of the operations.

Structure The present invention provides a recording medium having a heat-fusible ink layer mainly composed of a colorant and a binder that can be thermally transferred onto a support in a single operation, in which a silicone oil is inked in the heat-fusible ink layer. 0.01 to 5% by weight based on the total amount of the layer
A thermal transfer recording medium characterized by comprising:

In the above, as the support, a polyester film such as polyethylene terephthalate, a polyimide film, cellophane, capacitor paper, glassine paper, etc. are used. A heat-resistant film is preferred as the support.

In addition to carbon black, disazo pigments are used as coloring agents.
Already known coloring pigments such as phthalocyanine pigments are used.

As a binder, wax W4 wax such as carnauba wax, paraffin wax, ester wax, etc. and acetic acid and heat softening or heat softening such as nyl-ethylene copolymer, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, petroleum resin etc. Mixtures with meltable resins are used.

As these resins, vinyl polymers or copolymers such as vinyl acetate-ethylene copolymer, polyvinyl acetate, vinyl chloride-vinyl acetate are preferred, and vinyl acetate-vinyl acetate is particularly preferred.
Ethylene copolymers and polyvinyl acetate are preferred.

Furthermore, by using silicone oil, the transfer start temperature increases, making it difficult for scumming to occur.

The reason for this is thought to be that when the hot-melt ink is heated by the thermal head, the silicone oil prevents it from getting wet (transfer) with the paper even at the temperature at which transfer would normally begin, thereby preventing background smudges. In the case of image information, the thermal energy from the thermal head is large, so the ink melts sufficiently and is transferred to paper with high fluidity.

Moreover, the peeling noise generated when the ink layer is peeled off from the base material after transfer is also reduced.

The appropriate amount of this silicone oil is 0.01 to 5%,
More preferably, it is 0.1 to 21 ffi%; if it exceeds 5% by weight, uneven printing will occur, and if it is less than 0.01% by weight, scumming will occur during continuous printing or at high temperatures.

Next, examples will be described. % is by weight.

Example 1 Carbon black 15% paraffin wax 140°F (melting point 60°C) 53% Carnauba wax (melting point 83°C) 20% vinyl acetate
Ethylene copolymer 10% silicone oil (trade name KF-96, manufactured by Shin-Etsu Chemical@J) 2% toluene 400% or more were well dispersed in a ball mill to prepare an ink liquid. Add this ink liquid to a drying material @maximum 4g/l112,
It was coated on a PET film to make a thermal transfer recording medium.

Example 2 Carbon black 15% carnauba wax (melting point 83°C) 30% ester wax (melting point 5
6℃) 44% polyvinyl acetate 10%
Silicone oil (TSF-451, manufactured by Tokyo Shibaura Electric @) 1% or more was well kneaded with a hot roll to prepare an ink liquid. This ink liquid was coated onto a PET film to a thickness of 4 μm to prepare a thermal transfer recording medium.

Comparative Example 1 The silicone oil of Example 1 was mixed with liquid paraffin (reagent).
A thermal transfer recording medium was prepared in the same manner except for the following changes.

Comparative Example 2 A thermal transfer recording medium was prepared in the same manner as in Example 2 except that the silicone oil was changed to castor oil.

The obtained product is printed on a Ricoh serial printer TP.
I did a printing test using -2220. The condition of scumming was determined visually using a magnifying glass.

Further, the transfer start temperature was measured using a thermal gradient tester manufactured by Toyo'R Kikai.

The results are shown in the table.

Effect: The product of the present invention reduces background smearing during thermal transfer.
This has the effect of reducing the peeling sound generated when the ink layer is peeled off from the substrate after transfer.

Claims (3)

[Claims] (1) In a recording medium having a heat-fusible ink layer mainly composed of a colorant and a binder that are mostly thermally transferred onto a support in a single operation, silicone oil is added to the entire ink layer in the heat-fusible ink layer. A thermal transfer recording medium characterized by containing 0.01 to 5% by weight. (2) The thermal transfer recording medium according to claim (1), wherein the support is a heat-resistant film. (3) The thermal transfer recording medium according to claim (1), wherein the binder of the heat-melting ink layer contains a vinyl acetate-ethylene copolymer or polyvinyl acetate.