JP3101345B2 - Thermal transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording material used for a thermal transfer ribbon used in a thermal transfer type hard code printer, and more particularly, to a layer directly in contact with a thermal head which does not contain ink melted by heat. It is about.

[0002]

2. Description of the Related Art In recent years, as a method of recording information created by a computer, a word processor, or the like, a recording method by a thermal transfer method in which ink is melted by the heat of a thermal head is low-cost, has low noise,
In addition, it is rapidly spreading because of its simplicity like thermal recording paper. Accordingly, higher performance of the heat-sensitive transfer film such as higher printing speed and higher sensitivity is required. For that purpose, it is required to improve the performance of the layer which is in direct contact with the thermal head and which is in contact with the thermal head on the opposite side of the substrate surface formed by polyester etc. Has been done many times. As a typical example, Japanese Patent Application Laid-Open No.
There is a method of providing a heat-resistant resin such as a silicone resin or an epoxy resin as disclosed in JP-A-55-7467, such as a method of evaporating a metal such as aluminum as shown in JP-A-143152. Japanese Patent Application Laid-Open No. 56-15579 discloses a means for improving the smoothness in order to cope with an increase in printing speed.
No. 4, as disclosed in JP-A-57-129789, a method in which a highly lubricious inorganic pigment such as talc, mica, silica or the like is contained in a resin having heat resistance. There is a method of incorporating a surfactant such as oxyethylene stearate into a resin.

[0003]

However, Japanese Patent Application Laid-Open No.
In the method of evaporating a metal such as aluminum as disclosed in JP-A-143152, it is difficult to sufficiently increase the printing sensitivity if the cost of the evaporation equipment is too high.
The method of providing a heat-resistant resin such as silicone disclosed in Japanese Patent No. -7467 has a problem that it is difficult to have sufficient activity and heat resistance for thermal transfer printing. In the method of incorporating an inorganic lubricating pigment such as talc into a resin as disclosed in JP-A-56-155794, the lubricity may certainly be improved, but the inorganic substance has a very high hardness, so that a large number of printings are performed. Over time, the thermal head, which is the life of the printer, may be significantly damaged. In the method of adding a surfactant such as sodium stearate to a resin as disclosed in JP-A-57-129789, the lubricity is improved, but the surfactant may migrate to the ink surface during storage and affect printed images. There is.

It is an object of the present invention to provide a heat-sensitive transfer sheet which solves the above-mentioned problems and has both lubricity and heat resistance which can sufficiently withstand high-speed printing at low cost.

[0005]

As a result of intensive studies to solve the above-mentioned drawbacks of the prior art, the present invention has found that the resin having a glycidyl group or a carboxyl group in the back layer of the thermal transfer sheet has a smaller molecular weight than the resin having a carboxyl group. Silicon oil containing a specific group reactive with these groups is dissolved and mixed with an organic solvent such as methyl ethyl ketone and mixed and coated to form a flexible steric cross-linking structure in the silicon component. The present inventors have discovered that both the heat resistance that can withstand the heat received from the thermal head and the good slip that is indispensable for high-speed printing have been completed, and the present invention has been completed.

The term "resin containing a glycidyl group" as used in the present invention refers to a resin containing a glycidyl group in the molecule or at the terminal of the resin, a block copolymer or a graft copolymer. It is a product containing a glycidyl group as one composition of a copolymer such as a copolymer.

Specifically, glycidyl methacrylate, glycylin ester acrylate, diglycidyl adipate, glycidyl phthalate, isophthalate, etc. are obtained by an esterification reaction of epichlorohydrin with an aliphatic, alicyclic or aromatic polycarboxylic acid. Acid diglycidyl ester, terephthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester and the like. In addition, glycidyl groups are condensed with urea resin and melamine resin by condensation reaction to contain 1,4-glycidyl melamine, diglycidyl urea and silicon.
-Bis-((2,3-epoxypropoxy) dimethylsilyl) benzene and the like.

The term "resin containing a carboxyl group" as used in the present invention means a resin mainly used as a super-absorbent water-soluble resin, a resin containing a carboxyl group in the molecule or at the terminal of the resin, a block copolymer or the like. The one containing a carboxyl group as one composition of a copolymer such as a graft copolymer.

[0009] Specifically, starch-based products such as starch-acrylonitrile graft products and starch-acrylic acid graft products, cellulose-based products such as cellulose-acrylonitrile graft products, cross-linked polyacrylic acid products, polyacrylonitrile-based products, and the like. An acrylic material such as a saponified polymer can be used.

As the organic solvent for dissolving the resin formed in the present invention, those usually used for dissolving ink can be used, and as the alcohol type, methanol, ethanol, isopropyl alcohol (IPA), butanol,
Isobutanol, etc., and ketones such as methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIB)
K), cyclohexanone (anone) and the like, aromatic compounds such as toluene and xylene, and halogen-based compounds such as dichloromethane and trichloroethane, dioxane and tetrahydrofuran are used alone or in combination.

The base film on which the heat-sensitive transfer material of the present invention is applied may be of any type as long as it has heat resistance and strength capable of withstanding continuous printing, and has a thickness of 0.40 μm to 0.1 μm.
Polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, polyethylene isolate A plastic film such as phthalate or paper such as condenser paper or paraffin paper may be used.

As a method of applying the thermal transfer material of the present invention, a special coating method such as reverse roll coating, gravure coating, lot coating, air doctor coating, and blade coating does not require any special equipment.

[0013] As a condition for applying the heat-sensitive transfer material of the present invention, coating weight is about the imparting heat resistance enough without compromising sensitivity falls to between 0.45 g / m ² of 0.10 g / m ² Preferably, the drying conditions are 5 seconds to 12 hours at a temperature of about 80 ° C. to 95 ° C. so that the amino group and the glycidyl group react immediately.
It is preferable to carry out in a short time of about seconds.

As the heat-fusible ink layer used in the present invention, a heat-fusible substance used in a usual thermal transfer recording medium,
It is formed by appropriately prescribing and dispersing and applying a thermoplastic substance and fats and oils.

Specific examples of the heat-fusible substance include waxes such as paraffin wax, carnauba wax, microcrystalline wax, beeswax, selenium wax, low molecular weight polyethylene, low molecular weight polystyrene, and the like.
Low molecular weight polymer materials such as low molecular weight polyamide, rosin, petroleum resin, terpene resin and the like can be mentioned.

Specific examples of the thermoplastic substance include cellulose resins containing a functional group such as methylcellulose, hydroxyethylcellulose and carboxymethylcellulose, polyvinylpyrrolidone, polyvinylalcohol, and the like.
Examples include vinyl resins such as vinyl acetate resin, vinyl chloride resin, and vinylidene chloride resin, and polyacrylamide, gelatin, acrylic resin, and methacrylic resin.

As the colorant, inorganic and organic dyes or pigments used in printing inks, dyes and the like can be used, and the color of the colorant is not limited. Specific examples include direct dyes such as carbon black, red iron red, disazo yellow, Priliant Carmine 6B, Lake Red C, Fast Sky Blue, and Phthalocyanine Green, oily dyes, and basic dyes.

In the present invention, if necessary, an intermediate layer for improving adhesion to the substrate, a mat layer for matting and an ink layer may be transferred between the hot-melt ink layer and the substrate. It is also possible to provide a release layer or the like for assisting, or to provide an over layer on the hot-melt ink layer in order to improve thermal sensitivity or fixability.

[0019]

The present invention will be described in more detail with reference to the following examples. Of course, the present invention gives an advantage over the conventional product in the examples. However, in the examples limited to the present example, the back layer of the thermal transfer sheet is replaced with the C liquid,
After applying each of the liquids in the same manner as in Example 1, the printing was evaluated in the same manner as in Example 1. Table 1 shows the results. Comparative Example 1 After the respective liquids were applied in the same manner as in Example 1 except that the reactive A-terminal group-containing silicone oil was not mixed with the liquid A applied to the back layer of Example 1, The printing was evaluated in the same manner. Table 1 shows the results.

Comparative Example 2 The same procedure as in Example 1 was carried out except that the silicone oil containing both reactive amino groups at both ends was changed to a substance containing no reactive functional group in the solution A applied to the back layer of Example 1. After applying each of the liquids, printing evaluation was performed in the same manner as in Example 1. Table 1 shows the results.

[0021]

[Table 1] Print evaluation results Heat resistance: Printing condition when the printing level is the highest ○ indicates that the ribbon is not cut by heat Runnability: running condition when printing at about 80 mm ○ indicates no sticking development Printed product: printed at every 80 mm printing, every 10 mm ○ all Comparative Example 2 has heat resistance, but the silicone oil does not have a reactive functional group, so the silicone oil easily transfers to the ink surface, and the printed state and runnability are good. Did not.

Example 3 Solution A Glycidyl methacrylate 135 parts Silicon oil containing 0.5 part of reactive carboxyl groups at both ends 780 parts of methyl ethyl ketone 87 parts of methyl isobutyl ketone 87 parts of the solution A were mixed well, and after the mixture was stirred well, the amount of adhesion was about
It was adjusted to 0.50 g / m ² and applied on a 0.45 μm-thick polyester film, and dried at 90 ° C. for 10 seconds to form a back layer of the thermal transfer sheet. Thereafter, the following mixture was dispersed at 110 ° C. for 8 hours using a sand mill to prepare a liquid B.

Solution B Paraffin wax 60 parts Carnauba wax 20 parts Carbon black 15 parts Ethylene-vinyl acetate copolymer resin 5 parts The amount of the solution B applied to the surface not coated with the solution A with a hot melt gravure coater is 4.0. g / m ² to form a thermal transfer ink to form a thermal transfer film.

After cutting this thermal transfer film into a printable form, a personal word processor NL-1 manufactured by Ricoh Co., Ltd.
Printed using high quality paper at, and evaluated. Even if the print level of the thermal head was adjusted from the lowest level to the highest level at any time, there was no abnormality in the printing state and running state. Turned out to have.

Example 4 Solution C Glycidyl ester acrylate 135 parts Reactive carboxyl terminal 0.5 part Silicon oil containing groups 780 parts Methyl ethyl ketone 87 parts Methyl isobutyl ketone 87 parts
After applying each of the liquids in the same manner as in Example 1, the printing was evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 3 The same procedure as in Example 3 was followed, except that among the A liquids to be applied to the back layer of Example 3, the silicone oil containing a reactive carboxyl group at both ends was not mixed, and the other liquids were applied in the same manner as in Example 3. Printing evaluation was performed in the same manner as in Example 3. Table 2 shows the results.

Comparative Example 4 The same procedure as in Example 3 was carried out except that the silicone oil containing a reactive carboxyl group at both ends was changed to a substance containing no reactive functional group in the solution A applied to the back layer of Example 3. After applying each of the liquids, printing evaluation was performed in the same manner as in Example 3. Table 2 shows the results.

[0028]

[Table 2] Print evaluation results Heat resistance: Printing condition when the printing level is the highest ○ indicates that the ribbon is not cut by heat Runnability: running condition when printing at about 80 mm ○ indicates no sticking development Printed product: printed at every 80 mm printing, every 10 mm ○ all Comparative example 4 has heat resistance, but the silicone oil has no reactive functional group, so the silicone oil easily transferred to the ink surface, resulting in poor printability and runnability. Was.

Example 5 Liquid A 135 parts starch grafted with acrylic acid 0.5 part reactive glycidyl groups at both ends Silicon oil containing 0.5 part glycidyl groups 780 parts methyl ethyl ketone 87 parts methyl isobutyl ketone 87 parts A liquid was thoroughly mixed and stirred.
It was adjusted to 0.50 g / m ² and applied on a 0.45 μm-thick polyester film, and dried at 90 ° C. for 10 seconds to form a back layer of the thermal transfer sheet. Thereafter, the following mixture was dispersed at 110 ° C. for 8 hours using a sand mill to prepare a liquid B.

Liquid B Paraffin wax 60 parts Carnauba wax 20 parts Carbon black 15 parts Ethylene-vinyl acetate copolymer resin 5 parts The amount of Liquid B applied to the surface not coated with Liquid A with a hot melt gravure coater is 4.0. g / m ² to form a thermal transfer ink to form a thermal transfer film.

After cutting the thermal transfer film into a printable form, a personal word processor NL-1 manufactured by Ricoh Co., Ltd.
Printed on high quality paper at, and evaluated. Even if the print level of the thermal head was adjusted from the lowest level to the highest level at any time, there was no abnormality in the printing state and running state. Turned out to have.

Example 6 Liquid C 135 parts of crosslinked polyacrylic acid salt 0.5 part of reactive glycidyl groups at both ends Silicon oil containing groups 780 parts Methyl ethyl ketone 87 parts Methyl isobutyl ketone 87 parts
After applying each of the liquids in the same manner as in Example 1, the printing was evaluated in the same manner as in Example 5. Table 3 shows the results.

COMPARATIVE EXAMPLE 5 The same procedure as in Example 5 was carried out, except that the silicone oil containing a reactive glycidyl group at both ends was not mixed with the liquid A applied to the back layer of Example 5, but the solution was applied. Printing evaluation was performed in the same manner as in Example 5. Table 3 shows the results.

Comparative Example 6 The same procedure as in Example 5 was performed, except that the silicone oil containing a reactive glycidyl group at both ends was changed to a substance containing no reactive functional group in the solution A applied to the back layer of Example 5. After applying each of the liquids, printing evaluation was performed in the same manner as in Example 5. Table 3 shows the results.

[0035]

[Table 3] Print evaluation results Heat resistance: Printing condition when the printing level is the highest ○ indicates that the ribbon is not cut by heat Runnability: running condition when printing at about 80 mm ○ indicates no sticking development Printed product: printed at every 80 mm printing, every 10 mm ○ all Comparative Example 6 has heat resistance, but the silicone oil has no reactive functional group, so the silicone oil easily transferred to the ink surface, and the printed state and runnability were poor. Was.

[0036]

As described above, when the heat-sensitive recording material of the present invention is used for the back layer of a heat-sensitive recording sheet, excellent heat resistance and sufficient lubricity are obtained even when any heat-melted ink is used for the ink layer. Excellent images can be created even for high-speed printing records.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-137977 (JP, A) JP-A-63-191680 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/40

Claims (3)

(57) [Claims] 1. A reaction between a resin having a glycidyl group in a back layer and a silicone oil containing an amino group at both ends in a molecule, wherein an ink layer which is melted by heat is disposed on one surface of a base sheet. A heat-sensitive transfer sheet comprising a product. 2. An ink layer which is melted by heat is disposed on one surface of a base sheet, and the back layer is formed from a reaction product of a resin having a glycidyl group and a silicone oil containing a carboxyl group in a molecule. A heat-sensitive transfer sheet characterized in that: 3. A reaction between a resin having a carboxyl group in the back layer and a silicone oil having glycidyl groups at both ends in a molecule, wherein an ink layer which is melted by heat is disposed on one surface of the base sheet. A heat-sensitive transfer sheet comprising a material.