JP2001191652A - Thermal transfer medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer medium enabling formation of a transfer pattern having a clear print, with excellent fixing properties and abrasion resistance, on any object of transfer constituted of a material of every sort. SOLUTION: In the thermal transfer medium formed by laminating two or more hot-melt layers on a base, the surface layer of these layers positioned on the outermost surface is constituted of terpene-series resin of 60-90 wt.% and ethylene-vinyl acetate copolymer resin of 10-40 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermal transfer medium, and more particularly to a thermal transfer medium having a surface layer having an improved material composition.

[0002]

2. Description of the Related Art Hitherto, a thermal transfer medium has been used for transfer recording on a transfer member made of various materials including a packaging material. Such a thermal transfer medium is generally formed by laminating two or more heat-melting layers on a base material. Of these heat-melting layers, the material of the so-called surface layer located on the outermost surface and the material of the object to be transferred are There is a difference in the fixability of the colored pattern transferred to the transfer object depending on the combination of the above. To obtain good fixability, for example, if the material of the transfer object is a PP (polypropylene) resin, the surface layer If the material of the object to be transferred is a nylon resin, a material having a good fixability to the nylon resin is used as the surface layer. The fixing property and the abrasion resistance are ensured by individually corresponding to the material of the transfer-receiving body, for example, by using the compounded material. In particular, there is a large difference in the fixability of the transferred colored pattern between the case where the material of the transfer object is a PP resin such as OPP (biaxially oriented polypropylene) and the case where the material is a nylon resin. There was no thermal transfer medium exhibiting good fixability to both the toner and the nylon resin.

[0003]

SUMMARY OF THE INVENTION The present invention relates to OPP, C
It is excellent for any transfer material made of various materials such as PP resin such as PP (cast polypropylene), nylon resin, PET (polyethylene terephthalate) resin, PE (polyethylene) resin, and UV coated paper. It is an object of the present invention to provide a thermal transfer medium capable of transferring a colored pattern with fixability.

[0004]

Means for Solving the Problems The thermal transfer medium according to the present invention is characterized in that when a composition having a predetermined mixing ratio of a terpene-based resin and an ethylene-vinyl acetate copolymer resin is used as a material for the surface layer, various materials are used. Is based on the discovery that the toner can be transferred with excellent fixing properties to any one of the transfer-receiving members, and that the abrasion resistance is remarkably improved.

According to the present invention based on such a finding, in a thermal transfer medium comprising two or more heat-melting layers laminated on a base material, the surface layer which is the outermost layer of the heat-melting layers is a terpene resin 60 A thermal transfer medium comprising from about 90% by weight to about 10% by weight of an ethylene-vinyl acetate copolymer resin.

Hereinafter, a thermal transfer medium according to the present invention will be described.
A description will be given based on the general layer configuration. [Substrate] Examples of the substrate used in the thermal transfer medium of the present invention include polyester film, polysulfone film, polystyrene film, polyamide film, polyimide film, polycarbonate film, polypropylene film, cellophane, polyethylene film,
Examples include a synthetic resin film such as a polyethylene terephthalate film, a polyethylene naphthalate film, and a cellulose triacetate film, and thin paper such as condenser paper, glassine paper, and tracing paper. As the substrate, a heat-resistant film is preferable, and particularly, a polyester film is preferable from the comprehensive standpoint of price, mechanical strength, dimensional stability, heat resistance and the like.

[0007] These substrates usually have a thickness of 1 to 30 µm, preferably 2 to 15 µm. Also,
On the surface of the substrate opposite to the surface on which the hot melt layer is laminated,
A so-called heat-resistant protective layer containing a silicone resin, a fluorine-based resin, a reaction product of a polyvinyl butyral resin and an isocyanate resin, or an acrylic-based resin containing heat-resistant particles, etc., to protect the base material and the like from heating during transfer. Preferably, it is formed.

[Heat-melting layer] The present invention is characterized in that at least two heat-melting layers are laminated on the above-mentioned base material, and a surface layer thereof is constituted by the above-mentioned predetermined composition. The reason for providing two or more heat melting layers is as follows.
That is, if there is only one hot-melt layer, this layer is inevitably colored mainly. 1) This layer is in direct contact with a transfer object such as paper, and so-called smudge stain is likely to occur;
2) When printing on rough paper or the like having large surface irregularities, so-called voids (white spots) occur, and printing quality cannot be ensured;
3) it is not possible to ensure sufficient adhesiveness to the transfer target;
4) In the case of a roll ribbon type product, a so-called blocking phenomenon in which the surface of this layer adheres to an adjacent substrate surface during storage at a high temperature or the like is likely to occur; 5) Peelability from the substrate However, there is a problem that the thermal transfer sensitivity is insufficient. Therefore, generally, at least one heat-melting layer is further provided from the viewpoint of function separation, and the layer is provided with a function for solving and preventing such a problem. The present invention has been made mainly to solve the above-mentioned problem 3), in which at least two heat-melting layers are laminated on a base material, and a sufficient function as an adhesive layer is formed on the surface layer. , It is possible to ensure good adhesiveness to the transfer object.

[Surface Layer] As described above, the surface layer in the present invention functions as an adhesive layer, and is structurally the uppermost layer of the hot-melt layer, It plays a role in sufficiently securing the adhesive strength of the colored pattern. According to the present invention, as a material for the surface layer, a terpene-based resin (60 to 90% by weight) and an ethylene-vinyl acetate copolymer resin (hereinafter abbreviated as EVA as required) 10 to 4 are used.
By using a composition comprising 0% by weight, preferably a composition comprising 65 to 75% by weight of a terpene-based resin and 25 to 35% by weight of an ethylene-vinyl acetate copolymer resin, the material of the material to be transferred is obtained. Irrespective of whether or not it is possible, it is possible to transfer with good fixability to both a PP resin and a nylon resin.

[0010] When the terpene resin component in the resin composition is less than 60%, the fixability and transferability to the PP resin are particularly reduced. In particular, the fixing property and the transfer property to the nylon resin are lowered, and in any case, the selectivity to the material to be transferred is exhibited, which is not preferable. Further, the surface layer may contain a coloring agent as described below. In this case, the content of the coloring agent is preferably 30 to 50% by weight based on the total of 50 to 70% by weight of the terpene resin component and the EVA component. When the content of the colorant is less than 30% by weight, the fixability as the overall performance is excellent, but the transferability is poor. On the other hand, when the content is more than 50% by weight, the fixability and the transferability as the overall performance are inferior. Results.

The terpene resin used in the surface layer of the present invention includes terpene resins, modified terpene resins, hydrogenated terpene resins and terpene phenol resins.
Particularly, an aromatic modified terpene resin or terpene phenol resin is preferable. The softening point (Vicat softening point) is 9
It is preferable to use a material having a temperature of 0 to 130 ° C. because good fixability to various materials including a PP resin is exhibited.
It is more preferable to use one having a temperature of from 05 to 130 ° C. because the storage stability is further improved.

As the ethylene-vinyl acetate copolymer resin used in the surface layer of the present invention, those having a melt flow rate (melt flow rate) of 150 dg / min or less are preferably used. Further, the vinyl acetate content is preferably from 10 to 35%. The reason is that when an ethylene-vinyl acetate copolymer resin that satisfies such criteria is used, the balance between the storage stability of the resulting transfer pattern and the abrasion resistance can be well achieved. Furthermore, it is preferable to use one having a hardness (JIS K-6301) of 80 or more, since good sensitivity and scratch resistance can be obtained, and storage stability is improved. It is considered that these properties are improved because the higher the hardness of EVA, the larger the cohesive force. When the surface layer of the present invention is formed, the coating amount is preferably 0.5 to 3.0 g / m ² . The reason is that if the coating amount is less than 0.5 g / m ² , there is a possibility that the adhesive strength to the transferred object or the like may be insufficient,
On the other hand, if it is more than 3.0 g / m ^2, the storage stability of the thermal transfer pattern may be reduced. As used herein, the term “coating amount” refers to the weight of a solid content adhered per unit area when a solution containing each component of a layer to be formed is applied and dried, and is expressed in g / m 2. ^It shall be expressed in units of ² .

[0013] In the thermal transfer medium of the present invention, the layers other than the above-mentioned surface layer among the thermal fusion layers laminated on the base material may be a thermal fusion ink layer. The hot-melt ink layer mainly serves to color the thermal transfer pattern, and forms a colored pattern on the transfer target by being thermally transferred to the transfer target. This layer generally contains a colorant and a resin.
As the colorant contained in the hot-melt ink layer, pigments and dyes conventionally used in thermal transfer media can be suitably used, and examples thereof include carbon black, iron oxide, ultramarine, lake red, titanium oxide, and a basic base. , Neozapon,
Disazo, azo, anthraquinone, indigoid, soluble dye, sulfurized, phthalocyanine, quinone imine, cyanine, nitroso, nitro, stilbene, quinoline, pyrazolone, metal complex, benzoquinone, Examples include naphthoquinone-based pigments and dyes. In addition to the above colorants, the hot-melt ink layer includes thermoplastic resins such as polyethylene resins, poly (meth) acrylic resins, ethylene vinyl acetate resins, vinyl chloride resins, polyester resins, and thermosetting acrylic resins. A thermosetting resin such as a resin, an unsaturated polyester resin, an epoxy resin, or a polyamide resin, or an ultraviolet curable resin may be added.

Further, if necessary, an antioxidant such as a chroman compound or a phenol compound, a benzotriazole compound, a benzophenone compound, a 4-thiazolidone compound or an ultraviolet absorbing polymer may be added to the hot melt ink layer. May be contained. In addition, fine particles such as organic and / or inorganic fillers,
Release agents, plasticizers, dispersants, infrared absorbers, antistatic agents,
It may contain an antifoaming agent, a leveling agent, and the like. The coating amount of the hot-melt ink layer is preferably from 0.1 to 10.0 g / m ² , but may be appropriately determined depending on the specific gravity and the amount of the coloring agent such as a dye or pigment.

[0015] In the thermal transfer medium of the present invention, the layers other than the above-mentioned surface layer among the heat-melted layers laminated on the base material may be so-called release layers. The release layer is mainly provided to adjust the adhesive force between the hot-melt layer provided thereon and the substrate and to obtain a clear transfer pattern. That is, when heated from the back side of the base material (the side opposite to where the hot melt layer is laminated) by a thermal head or the like, the hot melt layer thereon plays a role of facilitating uniform peeling from the base material.

As the material of the release layer, those whose melting point or softening point is usually in the range of 50 to 150 ° C., especially 60 to 120 ° C., or those which can be in the range by mixing two or more kinds are preferably used. Usually, the main component is wax, but if necessary, a resin such as a thermoplastic resin or a thermosetting resin may be added. As the wax, for example, polyethylene wax, carnauba wax, bead wax, sasol wax, montan wax, rice wax, candelilla wax, rias wax, auricurie wax, microcrystalline wax, paraffin wax, ester wax and the like can be used. However, the present invention is not limited to these. Examples of the thermoplastic resin include polyethylene resin, poly (meth) acrylic resin, ethylene vinyl acetate resin, vinyl chloride resin, and polyester resin, and examples of the thermosetting resin include thermosetting acrylic resin and non-thermoplastic resin. Saturated polyester resin, epoxy resin, polyamide resin and the like,
It is not limited to these.

The release layer may optionally contain other components in addition to the above components, if necessary. For example, fillers such as organic fillers, alumina, clay and calcium carbonate, higher fatty acids, higher alcohols, higher fatty acid esters, amides, higher amines and the like can be mentioned. These may be used alone or in combination of two or more. Further, the release layer may contain a surfactant for controlling the release property. Examples of the surfactant include a polyoxyethylene chain-containing compound. Further, inorganic or organic fine particles (metal powder, silica gel, etc.) or oils (linseed oil, mineral oil, etc.) may be added.

In the formation of the release layer, it is preferable that the coating amount is 0.1 to 5.0 g / m ² .

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The thermal transfer medium of the present invention can be manufactured as follows. One side of a substrate such as a polyethylene terephthalate (PET) film or a polyester film having a thickness of 1 to 30 μm is coated with a liquid containing wax such as carnauba wax or polyethylene wax as a main component at 0.1 to 5.0 g / m ^2. , And dried to form a release layer. In this case, a solution containing a silicone resin or the like is applied to the surface on the opposite side of the substrate by 0.1%.
It is preferable to form a heat-resistant protective layer by applying the coating so as to have a coating amount of 0.8 g / m ² and drying the coating.

Next, on the release layer, a pigment or dye for producing a desired color, a thermosetting resin such as an amino resin or a thermoplastic resin such as a polyester resin, a cellulose resin, an acrylic resin, and the like, A solution containing a curing agent such as an isocyanate-based or urea-based resin and a resin that inhibits the reaction between the above-mentioned resin such as an epoxy resin and polyacrylamide and the curing agent is applied in an amount of 0.1 to 10 g / m ^2. After being applied, it is dried to form a hot-melt ink layer.

On this hot-melt ink layer, a solution containing the above-mentioned terpene resin and ethylene-vinyl acetate copolymer resin in a predetermined ratio, and further containing a predetermined amount of After coating so as to have a coating amount of about 3.0 g / m ^2, the coating is dried to form a surface layer. Thus, the thermal transfer medium of the present invention can be manufactured.

Materials such as resin used for forming each layer are added to water or an organic solvent such as toluene, methyl ethyl ketone, cyclohexane, butyl acetate or dioxane by a solvent coating method, and if necessary, a ball mill, a basket mill or the like. After it is uniformly dispersed using an attritor or the like, it is applied and dried on a layer located on or below a substrate, or is applied by a conventional hot melt coating method. In the application, conventionally used gravure coater, flexographic gravure coater, reverse coater, various blade coater, roll coater, air knife coater, bar coater, rod coater, gate roll coater, curtain coater, short dwell coater, etc. Various coating apparatuses can be used as appropriate. After application,
The finishing may be performed using a calendar such as a machine calendar, a TG calendar, a super calendar, and a soft calendar.

[0023]

(Example 1) A coating solution having the following composition (1) was applied to one surface of a PET film having a thickness of 5 μm at a coating amount of 0.1 μm.
The composition was applied using a direct gravure coater to a concentration of 3 g / m ² and dried to form a heat-resistant protective layer. Composition (1) Silicone resin 10% by weight Toluene 45% by weight MEK 45% by weight A coating solution of the following composition (2) was directly applied to the other surface of the PET film so that the coating amount was 0.5 g / m ^2. It was applied using a gravure coater and dried to form a release layer. Composition (2) 9% by weight of polyethylene wax 1% by weight of ethylene-vinyl acetate copolymer 90% by weight of toluene 90% by weight On this release layer, a coating solution of the following composition (3) is applied in an amount of 1.5 g / m ^2. Was applied using a direct gravure coater and dried to form a hot-melt ink layer. Composition (3) Polyester resin 18% by weight Carbon black 12% by weight Toluene 35% by weight MEK 35% by weight The following composition (4) [terpene resin (terpene phenol resin) and ethylene-vinyl acetate Table 2: Compounding ratio of polymer resin = 90% by weight: 10% by weight;
A-2] was applied using a direct gravure coater so that the coating amount was 1.0 g / m ^2, and dried to form a surface layer, thereby preparing a thermal transfer medium A-2. Composition (4) [A-2 in Table 3] Terpene phenol resin 18% by weight Ethylene-vinyl acetate copolymer resin 2% by weight Toluene 80% by weight

Example 2 In forming the surface layer, the composition was such that the compounding ratio of the terpene phenol resin and the ethylene-vinyl acetate copolymer resin was B-2 and C-2 in Table 2 [B in Table 3]. -2 and C-2] were used in the same manner as in Example 1 except for using the coating liquids of C-2 and C-2], respectively.

(Comparative Example 1) In forming the surface layer, the composition was such that the compounding ratio of the terpene phenol resin and the ethylene-vinyl acetate copolymer resin was D-2 in Table 2 [D- in Table 3
A thermal transfer medium D-2 was prepared in the same manner as in Example 1 except that the coating liquid of [2] was used.

(Comparative Example 2) In forming the surface layer, terpene phenol resin, polyester resin, epoxy resin and ethylene-vinyl acetate copolymer resin were independently contained as resin components [A-1 to D-1 in Table 1]. Thermal transfer media A-1 to D- in the same manner as in Example 1 except that the coating solutions having the compositions [A-1 to D-1 in Table 3] were used.
1 were prepared respectively.

[Table 1]

[Table 2]

[Table 3]

[Evaluation Test 1] The thermal transfer media A-1 to D-1 and A-2 to obtained in Examples 1-2 and Comparative Examples 1-2.
Using D-2, a thermal transfer printer (TEC B47
According to 4), a transfer pattern was formed on a packaging material composed of various materials, and the transferability of the transfer pattern was evaluated by visually confirming the transfer sensitivity. The evaluation was evaluated as ◎ when the print was clearly sharp, ○ when the print was clear, Δ when the print was faint, and × when the print was not clear. The results are shown in Table 4 using PP and nylon as typical packaging materials.

[Evaluation Test 2] The scratch resistance of the transfer pattern formed in the same manner as in Evaluation Test 1 was evaluated. JI
Scratch tester based on SL-0823 (Electric clock meter No. 416-TMI, manufactured by Yasuda Seiki Seisakusho)
A 10.9 mm diameter steel ball stuck to the tip of a friction element is brought into contact with the surface of the printing surface, and the terminal is loaded with a load lever at 88.2 kPa (converted value of 900 gf / cm ² ) and reciprocally slid on the surface. Was. The evaluation was performed by visually observing the change in the state of printing during 30 reciprocations, and ◎ indicates that there was no problem in printing, ○ indicates that there was no problem in printing, but を indicates that there was a trace of slight scratching, and A symbol that was legible but was scraped off by rubbing and was thin was marked as Δ, and a symbol that was indecipherable for printing and was scraped off by rubbing was rated as x. Table 4 shows the results.

[Comprehensive Evaluation] Table 4 also shows the evaluation results of the fixing property as a comprehensive evaluation item in consideration of the evaluation results of the transferability to each packaging material and the abrasion resistance.

[Table 4]

[Evaluation Results] As is apparent from Table 4, P
The thermal transfer medium A- showed good transferability, abrasion resistance and fixability for both the P-based packaging material and the nylon-based packaging material.
2, B-2 and C-2, and among them, B-
2 showed particularly excellent results. Among the other thermal transfer media, D-2 showed slightly inferior results in transferability, abrasion resistance and fixability to both PP-based packaging materials and nylon-based packaging materials. For the remaining thermal transfer media, P
The transferability to at least one of the P-based and the nylon-based was inferior, and none showed good scratch resistance or fixability. From the above, in the present invention, as the material of the surface layer, 60 to 90% by weight of the terpene resin and ethylene-
Good results are obtained when a composition comprising 10 to 40% by weight of a vinyl acetate copolymer resin is used, and 70% by weight of a terpene resin and 30% by weight of an ethylene-vinyl acetate copolymer 30
It has been found that particularly excellent results are obtained when a composition consisting of 5% by weight is used. The reason is considered to be that the balance between the adhesiveness and the sensitivity is well balanced in the case of such a composition.

Next, the effect of the addition of a coloring agent on the fixability and transferability of the thermal transfer medium was examined at the resin compounding ratio of the thermal transfer medium B-2 which showed particularly excellent evaluation results in the above evaluation.

Example 3 In forming the surface layer, Table 6 was used.
Of B-2-2 [mixture of terpene phenolic resin and ethylene-vinyl acetate copolymer resin (referred to as resin part)
And a colorant (referred to as a pigment part) = 50% by weight: 50
% By weight; a thermal transfer medium was prepared in the same manner as in Example 1 except that the coating solution of B-2-2 in Table 5 was used.

Comparative Example 3 In forming the surface layer, Table 6
In the same manner as in Example 3 except that the coating liquid of the composition B-2-1 [compounding ratio of the resin part and the pigment part = 40% by weight: 60% by weight; B-2-1 in Table 5] was used. A thermal transfer medium was made.

Example 4 In forming the surface layer, Table 6 was used.
In the same manner as in Example 3 except that the coating solution of the composition B-2-3 (the mixing ratio of the resin part and the pigment part = 70% by weight: 30% by weight; B-2-3 in Table 5) was used. A thermal transfer medium was made.

Comparative Example 4 In forming the surface layer, Table 6
In the same manner as in Example 3 except that the coating liquid of the composition B-2-4 of [Compound ratio of resin part and pigment part = 80% by weight: 20% by weight; B-2-4 in Table 5] was used. A thermal transfer medium was made.

[Evaluation Test and Comprehensive Evaluation] Examples 3 and 4
The transferability and the fixability of the thermal transfer media obtained in Comparative Examples 3 and 4 were evaluated in the same manner as described above. The results are shown in Table 5.

[Table 5]

[Table 6]

[Evaluation Results] As is clear from Table 5, in the thermal transfer medium according to the present invention, even when the surface layer having the material composition within the above-mentioned specific range further contains a coloring agent, the coloring does not occur. When the content of the agent is within the range of 30 to 50% by weight with respect to the total of 50 to 70% by weight of the terpene resin component and the EVA component, good transferability and fixability to various materials to be transferred are achieved. Is shown.

[0038]

According to the thermal transfer medium of the present invention, OP
P, CPP and other PP-based resins, nylon-based resins, PET-based resins, PE-based resins, UV-coated paper, etc. A transfer pattern having clear printing can be formed, and its industrial applicability is extremely large.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshiyuki Tomita 2-15-20 Chuo, Joto-ku, Osaka-shi, Osaka Prefecture General Co., Ltd. (72) Yoshikazu Ishihara 2--15 Chuo, Joto-ku, Osaka-shi, Osaka No. 20 F term in General Co., Ltd. (reference) 2H111 AA01 AA10 AA26 BA02 BA03 BA12 BA53 BA78

Claims (4)

[Claims] 1. A thermal transfer medium comprising two or more heat-melting layers laminated on a base material, wherein the surface layer located on the outermost surface of the heat-melting layer comprises 60 to 90% by weight of a terpene resin and ethylene-acetic acid. A thermal transfer medium comprising 10 to 40% by weight of a vinyl copolymer resin. 2. The thermal transfer medium according to claim 1, wherein the surface layer comprises 65 to 75% by weight of a terpene-based resin and 25 to 35% by weight of an ethylene-vinyl acetate copolymer resin. 3. The thermal transfer medium according to claim 1, wherein the surface layer further contains a coloring agent. 4. The content of the colorant is 50 to 70 in total of the resin.
4. The thermal transfer medium according to claim 3, wherein the amount is 30 to 50% by weight based on the weight.