JP3212440B2 - Thermal transfer recording material and heat-resistant image forming method - 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 for forming a heat-resistant stamped image and a method for forming a heat-resistant stamped image using the same.

[0002]

2. Description of the Related Art A thermal transfer recording material generally comprises a hot-melt ink comprising a colorant such as carbon black on a substrate and a vehicle comprising a wax and / or a hot-melt resin. The heat-meltable ink is 40 to 1 from the viewpoint of thermal transferability.
It has a melting point or softening point of about 20 ° C.

In recent years, thermal transfer recording materials have been used to print barcodes and the like used in the management of parts and products in the manufacturing process in manufacturing factories, product management in the distribution field, and article management in the field of use. Bar code printers and label printers are being used.

Some of such bar-coded articles are exposed to a high temperature after the bar-coded. For example, in the manufacturing process of a printed wiring board, 180 ° C.
Heat treatment is performed at about 250 ° C. in a semiconductor inspection process and about 450 ° C. in a cathode ray tube manufacturing process. Therefore, when a barcode or the like is printed on such an article by using a thermal transfer recording material and is to be managed, an image formed using a general thermal transfer recording material decomposes when heated to a high temperature as described above. Therefore, a thermal transfer recording material that can form a heat-resistant printed image that does not decompose or carbonize even when heated to a high temperature as described above is required.

Conventionally, a thermal transfer recording material for forming a heat-resistant image has been proposed, but an image which can withstand high temperatures as described above cannot be obtained.

For example, JP-A-63-179791 discloses a thermal transfer ink layer containing (a) a fatty acid amide or a fatty acid imide having a melting point of 120 ° C. or more, and (b) a polyamide resin or a vinyl resin having a melting point of 100 ° C. or more. Is described, but the heat resistance of the resulting image is only 140 ° C. at most.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a heat transfer recording material having excellent heat resistance and capable of forming an image capable of withstanding a high temperature of, for example, 250 to 600.degree. To provide.

[0008]

According to the first aspect of the present invention,
In a thermal transfer recording material in which a heat-fusible ink layer comprising a vehicle and a colorant is provided on a base material, the vehicle is a heat-fusible material, a polyphenylene sulfide resin,
Polyethersulfone resin, polysulfone resin, wholly aromatic polyimide resin, polyamideimide resin, polyetherimide resin, polyarylate resin, polyetheretherketone resin and fluorine resin , decomposition and carbonization temperature of 250 ° C The present invention relates to a thermal transfer recording material comprising at least one kind of heat-resistant resin, wherein the heat-resistant resin is contained in the heat-fusible ink layer in a fine particle state in an amount of 25 to 65% by weight.

A second aspect of the present invention relates to the thermal transfer recording material according to the first aspect of the present invention, which provides an image capable of withstanding a high temperature of 250 to 600 ° C.

The invention according to claim 3 relates to the thermal transfer recording material according to claim 1 or 2, wherein the heat-fusible material has a melting point or a softening point of 40 to 120 ° C.

[0011] Further, the invention according to claim 4 is characterized in that:
3. The thermal transfer recording material according to claim 3, wherein a release layer is provided between the hot-melt ink layer and the substrate.

[0012] The invention according to claim 5 provides the invention according to claims 1 to 5.
4. A printed image is formed on a transfer-receiving material using the thermal transfer recording material according to any one of 4. and then heated at a temperature not lower than the softening point or melting point of the heat-resistant resin and not higher than 600 ° C. to form the printed image. The present invention relates to a method for forming a heat-resistant stamped image, which comprises thermally fixing the image on a transfer-receiving member.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermal transfer recording material of the present invention is characterized in that the vehicle of the heat-fusible ink layer is a low-melting point or low softening-point heat-fusible material conventionally used as a vehicle component of this kind of ink layer. And the specific heat-resistant resin.

[0014] impression formed by using the thermal transfer recording material of the present invention Thus, the present because high temperature for a specific heat-resistant resin, be heated in example 2 50 ° C. or more high temperature,
It is not impossible to read due to decomposition or carbonization.

Therefore, the thermal transfer recording material of the present invention is:
Preferably used in the article to be heated in 2 50 ° C. or more high temperature to form the printed images, such as a bar code, for example.

The heat-fusible material used as a vehicle component in the present invention is for ensuring thermal transferability, abrasion resistance of an image before heat treatment, and the like. When the thermal transfer recording material of the present invention is used, a printed image can be formed under ordinary thermal transfer conditions.

In the method for forming a heat-resistant image of the present invention,
Using the thermal transfer recording medium, a printed image is formed on the transfer object, and then heated at a temperature not lower than the softening point or melting point of the heat-resistant resin and not higher than 600 ° C. to transfer the print image to the transfer object. Fix it.

By subjecting the formed image to the heat treatment, the specific heat-resistant resin in the image is partially softened or completely softened and melted. It is fixed and scratch resistance is improved. Therefore, a print image suitable for a bar code or the like can be obtained.

Next, the present invention will be described in detail.

The thermal transfer recording material of the present invention is provided with a heat-fusible ink layer comprising a vehicle and a colorant on a substrate,
The vehicle comprises a heat-fusible material, a polyphenylene sulfide resin, a polyether sulfone resin, a polysulfone resin, a wholly aromatic polyimide resin (which is a condensation polymer of an aromatic amino compound and an aromatic acid anhydride), a polyamide imide resin, It comprises at least one heat-resistant resin selected from the group consisting of ether imide resin, polyarylate resin, polyether ether ketone resin and fluororesin.

The hot-melt material is used as a vehicle for general hot-melt ink, and is mainly composed of waxes and / or hot-melt resins (including elastomers, hereinafter the same), and has a melting point or Softening point is 40 ~
It is about 120 ° C.

Examples of the waxes include natural waxes such as wood wax, beeswax, lanolin, carnauba wax, candelilla wax, montan wax and ceresin wax; petroleum waxes such as paraffin wax and microcrystalline wax; oxidized waxes and esters Synthetic waxes such as wax, low molecular weight polyethylene wax, wax α-olefin-maleic anhydride copolymer wax, urethanized wax, Fischer-Tropsch wax; higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid Higher fatty alcohols such as stearyl alcohol and docosanol; higher fatty acid monoglycerides, fatty acid esters of sucrose, fatty acid esters of sorbitan and the like; Amide such as amides and bisamides such as melting point can be used is of about 40 to 120 ° C.. These waxes can be used alone or in combination of two or more.

Examples of the heat-fusible resin include ethylene-vinyl acetate copolymer, ethylene-vinyl butyrate copolymer, ethylene- (meth) acrylic acid copolymer, and ethylene- (meth) acrylic acid alkyl ester copolymer. Merging (alkyl groups such as methyl, ethyl, propyl, butyl,
Hexyl, heptyl, octyl, 2-ethylhexyl,
Nonyl, dodecyl, hexadecyl and the like having about 1 to 16 carbon atoms), ethylene-acrylonitrile copolymer, ethylene-acrylamide copolymer, ethylene-N-methylolacrylamide copolymer, ethylene-styrene copolymer Such as ethylene-based copolymers; poly (meth) acrylates such as polylauryl methacrylate and polyhexyl acrylate; and chlorides such as polyvinyl chloride, vinyl chloride-vinyl acetate copolymer and vinyl chloride-vinyl alcohol copolymer. Vinyl (co) polymers; other polyester resins, polyamide resins, cellulose resins, petroleum resins, rosins, terpene resins, coumarone-indene resins, natural rubber, styrene-butadiene copolymers, isoprene polymers, chloroprene polymers Melting point or soft Point can be used is of about 40~120 ℃. These thermoplastic resins can be used alone or in combination of two or more.

Tables 1 and 2 show the structural formulas of typical examples of each of the heat-resistant resins together with physical properties.

[0025]

[Table 1]

[0026]

[Table 2]

These heat resistant resins do not decompose or carbonize even when heated to a high temperature of 250 ° C. or higher . But
If the heat temperature is too high, the heat-resistant resin will decompose,
Since the form is lost, the heating temperature is preferably 600 ° C or less.
New

From the viewpoint of the heat resistance of the image, it is preferable that the ratio of the heat-resistant resin in the vehicle is large. On the other hand, from the viewpoint of thermal transferability, the smaller the proportion of the heat-resistant resin, the better.

In consideration of the both, in the present invention, the content of the heat-resistant resin in the heat-fusible ink layer is preferably 25 to 65% by weight. When the content of the heat-resistant resin is less than the above range, the heat resistance of the printed image is not sufficient. On the other hand, when the content exceeds the above range, the thermal transferability is poor.

The heat resistant resin is contained in the ink layer in the form of fine particles.

In the present invention, in which the heat-resistant resin is dispersed in the form of fine particles, the ink has a relatively low melt viscosity at the time of thermal transfer, and thus has the advantage of good thermal transferability.
Therefore, the present invention is suitable when the content of the heat-resistant resin in the ink layer is relatively large in order to enhance the heat resistance of the printed image, for example, when the content is in the range of 25 to 65% by weight.

In the present invention, the average particle size is usually 0.1 to
50 μm, more preferably 0.1 to 25 μm is used.

Table 3 shows the usable modes (fine particle state) of the heat-resistant resin. In Table 3, the mark ○ means that the product can be used in that mode, and the mark X means that use is difficult or impossible.

[0034]

[Table 3]

As the colorant used in the present invention, various organic and inorganic pigments such as carbon black can be used. When the heat treatment temperature is as high as, for example, about 450 ° C. or more, carbon black and inorganic pigments are preferred. The content of the colorant in the ink layer is suitably 5 to 50% by weight, more preferably 10 to 20% by weight.

In the hot-melt ink layer of the present invention, in addition to the above components, a dispersant, a plasticizer, a surfactant (anionic, cationic, nonionic, amphoteric) and a coupling agent (silane, titanate). System, zirconate system, zircoaluminate system, etc.) can be appropriately blended.

The formation of the heat-fusible ink layer in the present invention can be carried out as follows.

The heat-fusible material is dissolved in a solvent in which the heat-fusible material dissolves but the heat-resistant resin does not. The heat-resistant resin powder is dispersed therein, and the colorant and other additives are dissolved and dispersed. A coating solution is prepared by applying the coating solution onto a base material (on a release layer if a release layer described later is provided), and then dried.

The coating amount of the hot-melt ink layer in the present invention is usually 2.5 to 7 g / m ² , more preferably 3 to 5 g.
/ M ² is appropriate.

Examples of the substrate include polyester films such as polyethylene terephthalate film, polybutylene terephthalate film, polyethylene naphthalate film, and polyarylate film, polycarbonate films, polyamide films, aramid films, polyethersulfone films, polysulfone films, polyphenylene sulfides. A film, a polyetheretherketone film, a polyetherimide film, a modified polyphenyleneether film, a polyacetal film, and various other plastic films generally used as a substrate film for this type of ink ribbon can be used. Alternatively, high-density thin paper such as condenser paper may be used. The thickness of the substrate is usually about 1 to 10 μm, and preferably 1 to 6 μm from the viewpoint that the thermal diffusion can be reduced and the resolution can be increased.

When the thermal transfer recording material of the present invention is used in a thermal transfer printer having a thermal head, a silicone resin, a fluororesin, a nitrocellulose resin, By providing a conventionally known stick prevention layer made of various heat-resistant resins modified by these, for example, silicone-modified urethane resin, silicone-modified acrylic resin, or a mixture of these heat-resistant resins with a lubricant. Is preferred.

In the thermal transfer recording material of the present invention, a release layer may be provided between the ink layer and the substrate.

In the case of the ink layer of the present invention, since the thermal transferability decreases as the proportion of the heat-resistant resin increases, the content of the heat-resistant resin in the ink layer is 47 to 65% by weight, particularly 55 to 65% by weight. %, It is preferable to provide a release layer.

As the release layer, a layer mainly composed of waxes can be generally used. A thermoplastic resin may be blended in an amount of 10% by weight or less of the release layer for adjusting the adhesiveness. As the wax and the thermoplastic resin, the wax and the heat-meltable resin exemplified as the heat-meltable material of the ink layer can be used.

The coating amount of the release layer is usually 0.3 to 1 g / m
^{About 2} is appropriate.

In order to form a printed image using the thermal transfer recording material of the present invention, an ink layer of the thermal transfer recording material is superposed on a transfer object, and thermal energy is applied to the ink layer in an image-like manner. A thermal head is generally used as a heat source for applying thermal energy, but any known one such as a laser beam, an infrared flash, and a hot pen can be used.

When the object to be transferred has a three-dimensional shape other than a sheet-like material, or when the surface thereof is a curved surface, thermal transfer using a laser beam is advantageous because heat energy can be easily applied.

The thermal transfer recording material of the present invention, because it gives the heat resistance of the good impression as above, preferably used to form printed images on the transfer member for receiving the heat treatment at 2 50 ° C. or more temperature Is done. If the temperature of the heat treatment applied to the transfer object is too high, the coloring agent or the heat-resistant resin is decomposed, and the form as a printed image is lost. It is particularly preferable that the temperature is 500 ° C. or lower.

Next, the method of forming a heat-resistant stamped image of the present invention will be described. In the method of the present invention, after forming a printed image on an object to be transferred, the softened point of the heat-resistant resin or A heat treatment is performed at a temperature not lower than the melting point and not higher than 600 ° C., and the image is thermally fixed on the transfer-receiving member to obtain a final heat-resistant image.

Here, the term "thermal fixing" means that the image is heated to a temperature higher than the softening point or the melting point of the heat-resistant resin so that the image is firmly fixed to the object to be transferred. By such heat fixing, a printed image having excellent abrasion resistance can be obtained.

The softening point of the heat-resistant resin is a temperature at which the resin starts to become tacky, and is usually higher than their glass transition point, for example, 50 to 50 degrees below their glass transition point.
It is higher by about 100 ° C, but may be higher. Therefore, for the heat fixing, it is preferable to heat the printed image to a temperature higher than the glass transition point of the heat-resistant resin, especially 50 to 100 ° C. higher than the glass transition point, or higher than such temperature. In particular, it is preferable to heat the resin to a temperature equal to or higher than the melting point of the heat-resistant resin to complete the heat fixing more completely.

On the other hand, if the temperature of the heat treatment is too high,
Since the colorant and the heat-resistant resin are decomposed and the form as an image is lost, the upper limit of the temperature of the heat treatment is usually about 600 ° C., more preferably about 500 ° C. from this point.

In the present invention, the above-mentioned heat treatment is usually carried out at the time of the heat treatment to be performed on the object to be transferred during the manufacturing process.

However, a heat treatment may be performed in advance separately from the heat treatment that the object to be transferred receives during the manufacturing process or the like. After the imprint is formed on the transfer object, it is transported before undergoing its own heat treatment.If the imprint receives external force such as rubbing during that time, it is subjected to heat treatment in advance to It is preferable to improve the properties. The thing of the present invention is inferior in the abrasion resistance before the heat treatment compared with the heat-fusible resin contained in the heat-fusible ink layer in a state compatible with the heat-fusible material, so that the heat-treated resin is subjected to heat treatment in advance. It is preferable to keep it. In this case, the heat treatment may be performed by heating the entire transfer-receiving body to the above-described temperature, or may be performed by heating the imprint by a heat iron, laser beam irradiation, or the like.

In the method of the present invention, as described above, a printed image may be directly formed on a target transfer object. However, after a print image is formed on a sheet-shaped transfer object (image receiving member) in advance, the image is formed. It may be affixed to an object to be transferred as an image receiving body by an appropriate means such as a heat-resistant adhesive. In this case, the heat treatment may be performed after the image receiving body on which the imprinted image is formed is attached to the transfer object, or the heat treatment may be performed before the image receiving body on which the imprint image is formed is stuck on the transfer object. You may.

As the sheet-shaped image receiving member, a heat-resistant sheet-like material is used. A cloth-like material of glass fiber or ceramic fiber, a material obtained by applying and impregnating a heat-resistant resin to this, or a sheet of glass or ceramic And a metal sheet.

Since the thermal transfer recording material of the present invention gives an image having excellent heat resistance, the transferred material can be used in the production process of a cathode ray tube, a fluorescent display tube, a printed wiring board, etc., in the inspection process of a semiconductor, etc., in the range of 250-600. ℃, especially 2
It is suitably used for forming a printed image on a material which is subjected to a heat treatment at a high temperature of 50 to 500 ° C.

Next, the present invention will be described with reference to experimental examples.

EXPERIMENTAL EXAMPLES 1-17 A 4 μm-thick polyethylene terephthalate film was coated on one side with a stick prevention layer made of silicone resin at a coating amount of 0.2 g / m ² , and the other side was coated with the ink shown in Table 4. Apply the liquid and dry it to apply 4 g / m
^{In 2} , an ink layer in which polyphenylene sulfide resin was dispersed in the form of fine particles was formed to obtain a thermal transfer recording material.

The ink coating solution was prepared by adding α-olefin-maleic anhydride copolymer wax (melting point: 74) to toluene.
℃) and ethylene-vinyl acetate copolymer (softening point 66 ℃)
Was dissolved therein, and a polyphenylene sulfide resin powder (average particle size: 24 μm) and carbon black were uniformly dispersed and prepared.

Experimental Examples 3, 5, 7, 9, 11, 13,
In Nos. 15 and 17, the following release layer coating solution was applied on the substrate and dried to form a release layer having an application amount of 0.9 g / m ² .
An ink layer was formed thereon.

Component Parts by weight Paraffin wax 20 Isopropyl alcohol 68 Toluene 12

Each of the thermal transfer recording materials obtained above is applied to a thermal transfer type bar code printer (B-30 manufactured by Tokyo Electric Co., Ltd.).
To form an image on a polyimide film under the conditions of applied energy of 30.5 mJ / mm ² , printing speed of 2 inch / sec, and strong platen pressure,
Heat treatment was performed at 10 ° C. for 1 hour. Heating for a short time is sufficient for heat fixing, but heating was performed for a long time of 1 hour for evaluation of heat resistance. The reflection density (OD value) of the image before the heat treatment and the image after the heat treatment were measured, and the scratch resistance was examined by the following method. Table 4 shows the results.

Abrasion Resistance An image of a checker flag pattern formed on a polyimide film (21 solid printed portions having a size of 4 mm × 4 mm and arranged in a checker flag pattern) was placed on a friction tester (Atlas). A cotton cloth was rubbed by reciprocating 30 times under a pressure of 510 g / cm ² using an AATCC clock meter (Model CM-1) manufactured by Electric Devices Co., Ltd. For the solid printing portion having the largest chipping among the 21 solid printing portions, the ratio (%) of the area of the notched portion to the original area (16 mm ² ) was determined, and the judgment was made according to the following criteria. 5: The ratio is 0%. 4: The ratio is less than 1%. 3: The ratio is 1% or more and less than 3%. 2: The ratio is 3% or more and less than 5%. 1: The ratio is 5% or more.

When the ratio is equal to or more than the reference value 3, there is no problem in reading with a bar code reader.

[0066]

[Table 4]

As is clear from Table 4, when the heat-resistant resin is contained in the ink layer in the form of fine particles, an image having a reflection density of 0.80 or more, which is a reflection density readable by a bar code reader, is obtained. To achieve this, the content of the heat-resistant resin in the ink layer is preferably 25 to 65% by weight. When the content of the heat-resistant resin in the ink layer is 47
When the weight is 65 to 65%, it is preferable to provide a release layer between the ink layer and the base material.
In the case of 5 to 65% by weight, it is necessary to provide a release layer.

Experimental Examples 18 to 25 In the same manner as in Experimental Examples 1 to 17, except that the ink layer coating liquid having the formulation shown in Table 5 was used, the heat-resistant resin was added to the ink layer. Was obtained in a dispersed state, and a test was conducted. Table 5 shows the results
Shown in

[0069]

[Table 5]

[0070]

According to the first to third aspects of the present invention,
By using a heat-fusible material and a specific heat-resistant resin in combination as a vehicle, an image having excellent heat resistance can be obtained while ensuring thermal transferability. The heat resistance is particularly good, and the scratch resistance of the image before the heat treatment is good.

According to the fourth aspect of the present invention, the heat transfer property is excellent by providing the release layer.

According to the fifth aspect of the present invention, by applying heat treatment to the obtained image, a heat-resistant image having excellent scratch resistance can be obtained.

Next, preferred embodiments of the present invention will be described.

(1) In the first aspect of the present invention, the content of the heat-resistant resin in the hot-melt ink layer is 47 to 65% by weight, and the content of the heat-resistant resin between the hot-melt ink layer and the substrate is And a thermal transfer recording material comprising a release layer.

Even when the proportion of the heat-resistant resin is large, the thermal transferability is good.

(2) The method according to claim 5, wherein the temperature of the heat treatment is 500 ° C. or less.

The abrasion resistance is improved while preventing the deterioration of the printed image.

(3) In the invention as set forth in claim 5, a sheet-shaped image receiving body is used as the object to be transferred, and an image formed on the image receiving body is attached to another object to be transferred, and then the heating is performed. A heat-resistant stamped image forming method for applying a process to fuse the stamped image to an image receiving member.

It is easy to form a printed image.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-211090 (JP, A) JP-A-1-255589 (JP, A) JP-A-58-16865 (JP, A) JP-A-59-865 67065 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (5)

(57) [Claims] 1. A thermal transfer recording material comprising a substrate and a heat-fusible ink layer comprising a vehicle and a colorant, wherein the vehicle comprises a heat-fusible material, a polyphenylene sulfide resin, a polyether sulfone resin, and a polysulfone. Resin, wholly aromatic polyimide resin, polyamideimide resin, polyetherimide resin, polyarylate resin, polyetheretherketone resin and fluororesin , the decomposition and carbonization temperature is 250 ° C or higher.
And at least one kind of heat-resistant resin, wherein the heat-resistant resin is contained in the heat-fusible ink layer in a fine particle state in an amount of 25 to 25%.
A thermal transfer recording material comprising 65% by weight. 2. The thermal transfer recording material according to claim 1, which provides an image which can withstand a high temperature of 250 to 600 ° C. 3. The thermal transfer recording material according to claim 1, wherein the heat-fusible material has a melting point or a softening point of 40 to 120 ° C. 4. The thermal transfer recording material according to claim 1, wherein a release layer is provided between the heat-fusible ink layer and the substrate. 5. A printed image is formed on an object to be transferred by using the thermal transfer recording material according to claim 1, and a temperature not lower than the softening point or melting point of the heat-resistant resin and not higher than 600 ° C. A method for forming a heat-resistant printed image, comprising heating the image at a temperature to thermally fix the printed image on the transfer object.