JPS6114989A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To provide the titled transfer material for a thermal printer improved in an ink exuding property and imparting sharp recording, by dispersing a mixture consisting of a specific colorant medium and a colorant in a resin solution and applying said mixture to a support to volatilize and dry the same. CONSTITUTION:A colorant comprising pigment (B) is mixed with a colorant medium (A) consisting of an oil-soluble metal sulfonate (i) and waxes (ii) and the resulting mixture is dispersed in a solution prepared by dissolving a resin (D) in a volatile solvent (C) while the obtained dispersion is applied to a support (E) and the component (C) is volatilized and dried to obtain an objective transfer material. For example, as the component (i), petroleum sulfonate represented by formula [wherein R is aromatic hydrocarbon having a paraffin side chain or a naphthene ring, (n) is 1, 2 and M is a metal] is pref. used and, as the component (ii), paraffin wax is pref. used. As the component (C), toluene is pref. used, as the component (D), vinyl chloride is pref. used and, as the component (E), polyethylene terephthalate is pref. used.

Description

DETAILED DESCRIPTION OF THE INVENTION +a) Industrial Application Field The present invention relates to a thermal transfer material. More specifically, in the present invention, the thermal transfer layer on the support forms a sponge-like structure, the solid ink is contained inside the sponge, and the thermal energy of the thermal head causes the solid ink to be contained inside the sponge. The present invention relates to a heat-sensitive transfer material in which ink can be melted and oozed out onto the heat-sensitive transfer material for transfer.

(bl) Prior Art and Problems The technology related to this type of thermal transfer material is already known. In this conventional thermal transfer material, resin forms a sponge-like structure, and solid ink is contained inside this sponge-like structure. Because of this, the thermal energy of the thermal head causes the ink in the thermal transfer layer to ooze out little by little, rather than being transferred all at once, and then transferred to plain paper, making it possible to record multiple times on the thermal transfer material. This thermal transfer material has a remarkable advantage over so-called one-time thermal transfer media, in which a heat-sensitive transfer layer containing pigments is applied directly to a support. When waxes are simply used as a medium, even if the solid ink is melted by the thermal energy of the thermal head, it does not bleed onto the thermal transfer material. Even with ink that uses a dispersant like this, the bleeding of the ink is not improved (see comparative example), so when used for multiple recording applications, the recording density is low, and the clarity of the transferred recording is poor. It had the disadvantage of lacking in.

In addition, when used for density gradation recording, there is a drawback in that density gradation changes are poor.

(C1 Purpose of the Invention The present invention provides a thermal transfer material that improves the ink bleeding performance, which is the above-mentioned drawback, allows clear recording, and can also be used for density gradation recording.

+dl Structure of the Invention That is, the present invention involves mixing a pigment colorant into a colorant medium consisting of an oil-soluble sulfonic acid metal salt and a wax, and dispersing this mixture in a solution of a resin dissolved in a volatile solvent. This is a heat-sensitive transfer material obtained by coating a support with this material and then drying it by evaporating a volatile solvent.

That is, the thermal transfer material of the present invention contains a solid ink in which a pigment colorant is mixed in a colorant medium consisting of an oil bath metal sulfonic acid salt and a wax, and this sponge-like structure has a resin. It is created when the volatile solvent in the solution evaporates and forms a dry film.

One feature of the present invention is that an oil-based sulfonic acid metal salt having a molecular weight of 400 or more is used. This oil-soluble sulfonic acid metal salt is called a sulfonate, and is broadly classified into petroleum sulfonate and synthetic sulfonate depending on the raw material.

Petroleum sulfonate is a metal salt obtained by neutralizing, extracting, and optionally refining oil-soluble sulfonic acid obtained by sulfonating a lubricating oil fraction of petroleum, and is represented by the following general formula.

(R8O3)nM...(1) (wherein, R is a 1- to 2-ring aromatic hydrocarbon group having a paraffin side chain and a naphthene ring in the molecule, n is 1 to 2,
M has a valence of n, for example, Na, Ca, Ba,
Indicates a metal element such as Mg. ) Synthetic sulfonates are obtained by sulfonating synthetic dialkylbenzenes, and can usually be represented as alkylarylsulfonic acid metal salts having one aromatic ring and mainly two alkyl side chains in the molecule.

Thus, when an oil-soluble metal sulfonate is included in the colorant medium, the ink oozes out onto the thermal transfer material to a satisfactory degree. -s of ionic group.

, M is adsorbed to the pigment and stably dispersed in the wax, so the pigment does not migrate into the resin film but oozes out with the wax when heated, resulting in good recording. .

Specifically, in the present invention, the oil-soluble sulfonic acid metal salts include product names Sulhole 400 (@I Matsumura Oil Research Institute), Sulhole 43o (the same company), Sulhole 465 (the same company), and Sulhole 500 (the same company). Sulfol Ca45N (Company), Sulfol Ca45 (Company), Sulhol Ba3ON (Company), Sulhol BaMB (Company), Sulhol R-10 (Company), Sulfomix #1 (Company), Sulfol Mix #1
00 (Company), Sulfomics #200 (Company),
Sulfomics #3 (Company), Morescoa 7 Bar 5C-45N (Company), Morescoa Anha-5C-
45 (Company), Morescore 7 Bar 5B-5ON (
(Company), Morescore 7)' Knee 5M-5ON (Company)
, same loop reseal #2152 (Japan loop reseal system, same Ca-5ON (Chuo Kasei 1lII), same same Ca-L
B30 (company), Ba-3ON (company), Ba-L
Examples include B70 (manufactured by the same company), Ba-No.

The waxes used in the thermal transfer material of the present invention include petroleum waxes such as paraffin wax, microcrystalline wax, and petrolactam wax; natural waxes such as carnauba wax, candelilla wax, rice wax, beeswax, and lanolin; montan wax,
Synthetic waxes such as polyethylene wax, Castor Wax, fatty acid amide, etc.; various other oxidized waxes, ester waxes, etc. are also used. Preferred are paraffin wax, microcrystalline wax, and polyethylene wax. The amount used is 40 to 60% by weight, preferably 45 to 55% by weight based on the total amount of the heat-sensitive transfer layer.

Further, as the pigment, a wide range of organic pigments and inorganic pigments can be used. The amount used is 10 to 30, preferably 15 to 25, 2 by weight based on the total amount of the heat-sensitive transfer layer.

The resins used in the present invention include vinyl polymers such as vinyl chloride, vinyl chloride/vinyl acetate copolymer, vinylidene chloride, acrylic ester, methacrylic ester, polyvinyl butyral, styrene, and styrene/maleic acid copolymer. ; Cellulose polymers such as cellulose acetate and cellulose nitrate; and other materials such as polyamides are used. Two or more of the above resins may be used, but combinations that are compatible with waxes should be avoided.The amount used is 20 to 50, preferably 20 to 50, based on the total amount of the thermal transfer layer.
It is preferably 0 to 40% by weight.

Volatile solvents used in forming the sponge-like structure of the thermal transfer material of the present invention include toluene, ethyl acetate, MEK
, methanol, and other organic solvents are used.

As the support, a plastic film made of polyethylene terephthalate, polyimide, polycarbonate, nylon, etc., capacitor vapor, or the like is used.

A heat-resistant layer may be provided on the side of the support opposite to the side on which the heat-sensitive transfer layer is provided, and an adhesive layer may be further provided between the heat-sensitive transfer layer and the support to bond the two.

tel Examples Hereinafter, examples of the present invention will be shown. In the examples, parts are parts by weight.

Example 1 A resin liquid is prepared by dissolving 20 parts of vinyl chloride/vinyl acetate copolymer in a mixed volatile solvent of 40 parts of toluene and 40 parts of MEK.

On the other hand, polyethylene wax (product name, WBISSEN
-0453, 18.5 parts of Nippon Tank 11all), 1°5 parts of Thruhole Ca45N (trade name, the above-mentioned company), 5 parts of carbon blank, and a mixed volatile solvent of 25 parts of toluene and 50 parts of MEK were mixed in an attritor for 60 minutes. ℃ for 2 hours, and 100 g of this mixture was added to the previously prepared resin solution 62.
5 g and uniformly dispersed for an additional hour at room temperature.

The ink composition obtained by the above operation is uniformly applied to a PET film of 6 microns to a coating thickness of about 10 microns, and the volatile solvent is evaporated and dried to obtain a heat-sensitive transfer material.

Printing was repeated on the same spot on the resulting thermal transfer material using a thermal printer, and the density was measured using a Macbeth reflection densitometer. The difference in the print density of the printed character pattern is that the optical reflection density is 0.35, which is a small decrease of 10.
The character patterns after the first printing were also sufficiently readable.

Separately, when we printed on thermal transfer material by changing the head temperature of the thermal head in five stages, we found that the print density of the transferred character pattern changed linearly in proportion to the head temperature, which was satisfactory. A progressive density gradation record was obtained.

Comparative Example Example 1 except that 4 parts of pentaerythritol diester lanophosphate (trade name: Pentalan DSE, Daiichiri Roda Chemical ■) was used instead of Sulhole Ca45N, 12 parts of polyethylene wax, and 9 parts of carbon blank. A thermal transfer material for comparison was prepared in the same manner.

Printing was repeated on the same location on the obtained thermal transfer material using a thermal printer, and the density was measured in the same manner as in Example 1. It was found that the first printed character pattern and the fifth printed character pattern were transferred to the plain paper to be transferred. The difference in print density of the printed character pattern was such that the optical reflection density was 0.6, which was a large decrease, which was a practical problem.

Example 2 In Example 1, moresco amber-3 (, -43N (described above)) was used at 14.5
A heat-sensitive transfer material was prepared in the same manner, except that the amount of polyethylene wax was 14.5 parts, and the carbon blank was 9 parts.

Printing was repeated on the same spot on the resulting thermal transfer material using a thermal printer, and the density was measured in the same manner as in Example 1. It was found that the first printed character pattern and the tenth printed character pattern were transferred to the plain paper to be transferred. As for the difference in the print density of the printed character pattern, the optical reflection density was 0°4, which was a small decrease, and good results were obtained.

Example 3 In Example 1, Hoechst wax KST (trade name, Hoechst Javan@
), 2.5 parts of through-hole Ca45N, and 6.3 parts of carbon blank were used as a thermal transfer material. A thermal printer was used on the same part of the obtained thermal transfer material. When printing was repeated and the density was measured in the same manner as in Example 1, the difference in print density between the first printed character pattern and the fifth printed character pattern transferred to the plain paper was that the optical reflection density was 0. Good results were obtained with a small decrease of 0.4, but the difference in print density between the first printed character pattern and the 10th printed character pattern showed a relatively large decrease and a slight lack of density was observed.

Example 4 In Example 1, polyethylene wax was 12.2 parts, Throughhole Ca 45N was 3.8 parts, carbon blank was 9 parts, and the amount of Throughhole Ca 45N was 10.1% by weight based on the total amount of the thermal transfer layer. A thermal transfer material was prepared in the same manner except for the following.

Printing was repeated on the same spot on the resulting thermal transfer material using a thermal printer, and the density was measured in the same manner as in Example 1. It was found that the first printed character pattern and the tenth printed character pattern were transferred to the plain paper to be transferred. Regarding the difference in print density of the printed character pattern, the optical reflection density was 0°4, which was a small decrease and good results were obtained. It was observed that stains were partially generated due to scratches.

(f) Effect of the invention

Claims (1)

[Claims] A pigment coloring agent is mixed into a coloring agent medium consisting of an oil-soluble metal sulfonic acid salt and waxes, and this mixture is dispersed in a solution of a resin dissolved in a volatile solvent, and this is coated on a support. A thermal transfer material made by volatilizing and drying a solvent.