JPS60245594A - Heat transfer recording medium - Google Patents

Abstract

PURPOSE:To prevent a recording paper from being contaminated, by a construction wherein a lubricant solid at normal temperature and melted when being heated by a thermal head is made to separate out at the surface of a heat- fusible ink layer. CONSTITUTION:The lubricant must be capable of being mixed in a heat-fusible ink layer, be solid at normal temperature, be heat-fusible, separate out upon solidification of the ink layer, and have such a melting point that it is melted when being heated by a thermal head. The amount of the lubricant used is preferably 1-20pts.wt. per 100pts.wt. of the dried weight of the heat-fusible ink exclusive of the lubricant. If the amount of the lubricant is excessively large, the ink layer as a whole becomes crystalline, and scaling of the ink layer occurs. If the amount of the lubricant is less than the above range, the desired effect can not be obtained. Accordingly, since the contact frictional resistance between the surface of the ink layer and a recording paper is markedly lowered, printed images are not easily broken even when being rubbed by fingers or the like, and durability of the printed images can be enhanced.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is an image forming apparatus such as a typewriter or a computer printer, in which heat-melting ink is transferred to recording paper by heating a thermal head to form an image. The present invention relates to a thermal transfer recording medium that holds the above-mentioned heat-melting ink and is used to form a thermal transfer recording medium.

[Prior art] Conventionally, this type of thermal transfer recording medium has been formed by coating a base material such as a resin film or high-density paper with a heat-melting ink layer that is solid at room temperature and is a mixture of a binder agent such as wax and a colored pigment. This heat-melting ink layer is pressed against a recording paper, heated by a thermal head, and the ink in the heated areas is melted and transferred to the recording paper.

[Problems to be Solved by the Invention] In such conventional technology, due to sliding contact or pressure contact between the heat-melting ink layer and the recording paper, the ink is recorded in areas that are not heated by the thermal head. There was a problem in that it transferred to paper and stained the recording paper.

[Means for Solving the Problems] In order to solve these problems, the present invention provides a structure in which a lubricant that is solid at room temperature and melts when heated by a thermal head is deposited on the surface of a heat-fusible ink layer. That is.

[Function] Due to the printing structure, the contact friction resistance between the surface of the heat-melting ink layer and the recording paper is significantly reduced.

[Effects of the Invention] As a result of exhibiting such an effect, the ink layer in a solid state does not adhere to the recording paper, resulting in the effect that staining of the recording paper is prevented.

Furthermore, since the lubricant is deposited on the surface of the ink after it has been transferred to the recording paper, even when the printed image is rubbed with a finger, the printed image does not easily crumble and the durability of the printed image can be improved.

[Embodiments of the Invention] The lubricant is a heat-fusible substance that is solid at room temperature and is mixed with the heat-fusible ink layer and precipitates when the ink layer solidifies, and is melted by heating with a thermal head. It must have a similar melting point.

The amount of lubricant to be used is preferably 1 to 20 parts by weight per 100 parts by weight of the dry weight of the heat-melting ink excluding the lubricant, and if the amount of lubricant used is too much than this range, The entire ink layer becomes crystalline, the adhesion of the ink layer to the substrate is impaired, and the ink layer peels off. In addition, if the amount of lubricant used is too less than this range, the desired effect will not be achieved.

Examples of such lubricants include the following.

(2) Fatty acid-based lubricant General formula: Straight chain saturated fatty acids represented by the formula % (in the formula, n is an integer from 6 to 28) are preferred.

Side chains or unsaturated bonds or other functional groups (-Ko, -N
12) is also effective, but as the number of side chains increases, the amount of precipitation on the surface decreases, so it is necessary to increase the amount added.

Typical examples of fatty acid-based lubricants include stearic acid, lauric acid, palmitic acid, behenic acid, stearic acid, lignocene phosphoric acid, melisic acid, montanic acid, cerotic acid, and 12-hydroxystearic acid.
It is not limited to these.

(2) Aliphatic dibasic acid lubricant General formula: Straight chain saturated aliphatic dibasic acids represented by the formula % (in the formula, n is an integer from 3 to 28) are preferred.

Side chains or unsaturated bonds or other functional groups (-OH, -
Nl2, etc.) are also effective.

Representative examples of the aliphatic dibasic acid lubricant include, but are not limited to, adipic acid, sebacic acid, glutaric acid, pimelic acid, and azelaic acid.

(2) Aliphatic alcohol lubricant General formula: Straight chain saturated aliphatic alcohols represented by the formula % (where n is an integer from 10 to 30) are preferred.

Side chains or unsaturated bonds or other functional groups (-OH, -
Nl2, etc.) are also effective.

Typical examples of the aliphatic alcohol lubricant include stearyl alcohol, lauryl alcohol, cetyl alcohol, ceryl alcohol, rough cell alcohol, etc., but are not limited to these.

■Fatty acid ester lubricant general formula: % formula% (In the formula, m and n are integers, and m+n is 10 to 35
A straight chain saturated aliphatic alcohol ester of a straight chain saturated fatty acid represented by the following formula is preferred.

Side chains or unsaturated bonds or other functional groups (-ON, -
Nl2, etc.) are also effective.

Typical examples of fatty acid ester lubricants include ethyl stearate, lauryl stearate, ethyl behenate,
Examples include, but are not limited to, hexyl behenate and behenyl myristate.

(2) Fatty acid amide lubricant Amides and bisamides of fatty acids mentioned in (2) above are preferred. Typical examples of fatty acid amide lubricants include stearamide, lauric acid amide, etc., but are not limited to these.

Note that among the compounds represented by the above general formulas, those which are not solid at room temperature are not included in the lubricant referred to in the present invention.

In addition to the lubricants exemplified above, any lubricant having the same performance as these may be used, and not only one type of these lubricants may be added, but multiple types may be appropriately mixed and used. .

The other components of the heat-melt ink are not particularly limited, and waxes and heat-melt resins similar to those in conventional heat-melt inks are used as the main components of the binder, and colored pigments and dyes are used as the main components of the colorant. It is fine as long as it is done.

Moreover, conventional materials can be used for the base material and others, and the ink application method and coating thickness may be the same as conventional ones.

Regarding the components other than the lubricant of this heat-melting ink,
As mentioned above, the present invention is not explained in detail because it is the same as the conventional one, but the present invention is not limited to the following embodiments.

[Examples] Next, Examples 1 to 14 and Comparative Examples 1 to 2 will be described with reference to Examples and Comparative Examples to explain the thermal transfer recording medium of the present invention. A heat-melt ink is prepared by dispersing and mixing the lubricant components, and the ink is coated with a thickness of 6 mm by a hot-melt coating method.
A thermal transfer recording medium was manufactured by applying the mixture to a thickness of 4μ on a polyester film having a thickness of 4μ.

Table 1 (Note): Paraffin wax manufactured by Etsuso Standard Table 2 In the recording media of Examples 1 to 14, it was observed that crystalline lubricant was present on the entire surface of the ink layer, but in the comparative example In Comparative Example 1, no lubricant was present on the surface of the ink layer, and in Comparative Example 2
The precipitated lubricant was in liquid form.

Each of the above-mentioned recording media was cut into a ribbon shape with a width of 20M and a length of 300M, and the obtained ribbon was overlapped with a high-quality paper on the ink layer side, and 100g/cIA2 of pressure was applied.
The ribbon was moved linearly with respect to the high-quality paper at a speed of 00 m+/Sec, and it was examined whether the high-quality paper was stained or not.

As a result, in Examples 1 to 14, no stains were observed on the high-quality paper, but in Comparative Example 1, the ink was transferred to the traces of the sample on the high-quality paper and the paper was stained. Furthermore, in Comparative Example 2, the lubricant soaked into the traces of the ribbon on the high-quality paper.

Using ribbons newly made from each of the recording media mentioned above, an image was formed on high-quality paper using a word processor equipped with a thermal transfer printer (Gear Node 45 manufactured by Canon). No stains were observed, but in Comparative Example 1, there were linear black marks from dragging the ribbon on the high-quality paper. Furthermore, in Comparative Example 2, the lubricant had soaked into the entire surface of the high-quality paper where the ribbon was in contact with the paper, making it dirty.

Claims (1)

[Claims] 1. A thermal transfer recording medium in which a lubricant that is solid at room temperature and melts when heated by a thermal head is deposited on the surface of a heat-melting ink layer.