JPH09123384A - Thermal plate making equipment - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To attach a resin in the vicinity of a heating element for perforation and to cause a printing failure. SOLUTION: A heat sensitive stencil sheet 7 having a thermal head having a perforation heating element R1 and having a resin layer 9 deposited on a porous support 8 is provided with the perforation heating element R1 of the thermal head.
In the heat-sensitive plate making apparatus, the resin layer 9 of the heat-sensitive stencil sheet 7 is melted by the heat generated by the perforation heating element R1 while being conveyed upward, and the predetermined holes 7a are formed in the resin layer 9 of the heat-sensitive stencil sheet 7. The head is a heating element R1 for drilling.
On the downstream side of the heat-sensitive stencil sheet 7 in the conveying direction (direction A), there is a heat retaining heating element R2 having an electric resistance value smaller than that of the perforation heating element R1, and the heat retaining heating element R2 is caused to generate heat. As a result, the heat-sensitive stencil sheet 7 located between the heat-generating element R1 for perforation and the heat-generating element R2 for heat retention is maintained at a temperature higher than the glass transition point of the resin layer 9 of the base sheet 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a heat-sensitive plate making apparatus for making holes in a heat-sensitive stencil sheet using a thermal head.

[0002]

2. Description of the Related Art In a conventional thermal head incorporated in a thermal plate making apparatus, a glaze layer 12 made of glass is deposited on a substrate 11 made of an electrically insulating material such as alumina ceramics as shown in FIG. Layer 1
A resistive layer 13 made of tantalum nitride or the like and a pair of conductive layers 14 are sequentially deposited on the upper surface 2 to form a heating element R between the pair of conductive layers 14, and the heating element R or the like is further covered. It has a structure in which a protective film 15 made of silicon nitride or the like is deposited.

A thermal plate making apparatus incorporating such a thermal head applies a predetermined electric power between a pair of conductive layers 14 of the thermal head based on a print signal from the outside, and a resistance sandwiched between the pair of conductive layers 14. A body layer 13 (heating element R) is selectively heated by Joule heat, and the generated heat is applied to a heat-sensitive stencil sheet (a porous support 17 made of Japanese paper or the like, and a resin layer 18 made of wax or the like is applied thereto). ), The resin layer 18 of the heat-sensitive stencil sheet 16 is partially melted to form the holes 16a, thereby functioning as a heat-sensitive plate making apparatus.

The heat-sensitive stencil sheet 16 is used in, for example, a stencil printing machine after the holes 16a are formed as described above, and printing ink is provided on one main surface side of the heat-sensitive stencil sheet 16. Is arranged on the other main surface side, and by adhering the ink to the material to be printed through the holes 16a formed in the heat-sensitive stencil sheet 16, predetermined characters and images are formed on the material to be printed. There is.

[0005]

However, in this conventional heat-sensitive plate making apparatus, the heating element R of the thermal head is caused to generate Joule heat, and the resin layer 18 of the heat-sensitive stencil sheet 16 is used.
When the holes 16a are formed in the heat-sensitive stencil paper 16, the heat-sensitive stencil sheet 16 is conveyed in a predetermined direction and a part where the holes are formed is moved a little from above the heating element R. When it is cooled to a temperature lower than the glass transition point, its viscosity rapidly increases and it becomes highly tacky. As a result, a part of the highly adhesive resin layer 18 is transferred and adhered in the vicinity of the heating element R of the thermal head, and dust or the like is further adhered to the adhered resin to stabilize the heat-sensitive stencil sheet 16. It may cause a great obstacle in running, or the heat-sensitive stencil sheet 16 cannot be brought into good contact with the heating element R due to the adhered resin, so that desired holes 16a can be well formed in the heat-sensitive stencil sheet 16. It had the disadvantage of becoming impossible.

[0006]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and has a thermal head having a heating element for perforation, and a heat-sensitive stencil sheet having a resin layer deposited on a support. In the heat-sensitive plate making apparatus for transporting on the heat-generating body for perforation of the thermal head, melting the resin layer of the heat-sensitive stencil sheet by heat generated by the heat-generating body for perforation, and forming predetermined holes in the resin layer of the heat-sensitive stencil sheet. The thermal head has a heat retaining heating element having an electric resistance value smaller than that of the perforating heating element, on the downstream side of the perforating heating element in the transport direction of the heat-sensitive stencil sheet. The heat-sensitive stencil sheet located between the heat-generating element for perforation and the heat-generating element for heat retention is kept at a temperature higher than the glass transition point of the resin layer of the base sheet by heating the heat-generating element.

[0007]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a plan view of a thermal head incorporated in the heat-sensitive plate making apparatus of the present invention, and FIG. 2 is a sectional view taken along line XX of FIG.

Reference numeral 1 in the drawing is a substrate of the thermal head,
On this substrate 1, a glaze layer 2, a resistor layer 3, a conductive layer 4
The thermal head is formed by attaching a to 4c, the driver IC 6 and the like. The heat-sensitive stencil sheet shown by 7 in FIG. 2 is obtained by coating a resin layer 9 made of a resin such as wax on one main surface of a porous support 8 made of Japanese paper.

The substrate 1 of the thermal head is made of an electrically insulating material such as alumina ceramics, and the glaze layer 2, the resistance layer 3, the conductive layers 4a to 4c, the driver IC 6 and the like are deposited on the upper surface of the substrate 1 to support them. Functions as a support member.

The substrate 1 made of alumina ceramics or the like is formed into a sludge form by adding and mixing an organic solvent and an organic solvent to a raw material powder such as alumina, silica or magnesia. A ceramic green sheet is obtained by adopting, and thereafter, the ceramic green sheet is punched into a predetermined shape by a punching method and fired at a high temperature (about 1600 ° C.).

A glaze layer 2 made of glass or the like is partially adhered to the surface of the substrate 1, and the glaze layer 2 has a heating element R1 for perforation and a heating element R2 for heat insulation provided on the upper surface thereof. The effect of keeping the thermal response characteristics of the thermal head good by projecting it toward the heat-sensitive stencil sheet 7 and making them closely adhere to the heat-sensitive stencil sheet 7, and by storing and dissipating the heat generated by the perforation heating element R1 and the like. To do.

When the glaze layer 2 is made of, for example, glass, a glass paste of a predetermined component is mixed with an appropriate organic solvent or an organic solvent, and a glass paste obtained by mixing the glass paste is conventionally formed on a predetermined region of the upper surface of the substrate 1. It is partially applied to the upper surface of the substrate 1 by applying it to a predetermined thickness by a known screen printing method and baking it at a temperature of about 1700 ° C.

On the upper surface of the substrate 1 on which the glaze layer 2 is deposited, a resistance layer 3 made of an electric resistance material such as tantalum nitride and conductive layers 4a to 4c made of a metal material such as aluminum are sequentially formed. A heat-generating body for perforation R1 and a heat-generating body for heat retention R2 are provided in the region which is adhered and sandwiched by these conductive layers 4a to 4c.

The perforation heating element R1 and the heat retention heating element R2 are arranged such that the heat retention heating element R2 is located downstream of the perforation heating element R1 in the transport direction (direction of arrow A) of the heat-sensitive stencil sheet 7. It is located on the glaze layer 2 and has a length of 0.
They are connected in series by a conductive layer 4b having a thickness of about 1 to 0.3 mm.

The perforation heating element R1 is a heat-sensitive stencil sheet 7.
When a plurality of perforation heating elements R1 generate heat, a plurality of them are arranged at a predetermined interval in a direction orthogonal to the transport direction of
High temperature (heat-sensitive stencil paper 7
The temperature of the heat generating portion R1 does not spread to the area of the adjacent heat generating element R1.
10 or more per 1 mm so that it is only around 1,
The distance between adjacent heating elements R1 is 25 μm or more.

The perforation heating element R1 heats the resin layer 9 of the heat-sensitive stencil sheet 7 conveyed thereon at a predetermined temperature, and melts the resin layer 9 so that the resin layer 9 of the heat-sensitive stencil sheet 7 has predetermined holes. If the resin layer 9 of the heat-sensitive stencil sheet 7 is formed of wax having a melting temperature of 120 ° C., it will generate heat at a predetermined temperature (eg, 180 ° C.) higher than the melting temperature. Is set. For example, when the electric resistance value of the perforation heating element R1 is set to 3 kΩ, the perforation heating element R1 can be heated to a temperature of 180 ° C. by setting the applied energy to 25 mJ / mm ² .

On the other hand, the heat-retaining heating element R2 is adjusted to have an electric resistance value smaller than that of the perforating heat-generating element R1, and Joule heat is generated when a predetermined electric power is applied through the conductive layers 4a-4c. And the heat-sensitive stencil sheet 7 positioned between the perforation heating element R1 and the heat retention heating element R2.
Is kept at a temperature higher than the glass transition point of the resin layer 9 of the base paper 7 and lower than the melting point of the resin layer 9. For example, when the resin layer 9 is formed of wax having a glass transition point of 80 ° C., the electric resistance value of the heat retaining heating element R2 is set to 1.25 kΩ and the applied energy is 10 mJ.
By setting it to be / mm ² , the heat retaining heating element R2 can be heated to a temperature (90 ° C.) higher than the glass transition point of the resin layer 9 and lower than the melting point.

The surface temperature of the heat-sensitive stencil sheet 7 heated by the perforation heating element R1 and the heat retention heating element R2 is as shown in FIG. In the heating element R1 for perforation and the heating element R2 for heat retention of the thermal head used for the measurement of the surface temperature, the resistance layer 3 is formed of TiSiO ₂ to a thickness of 500 Å, and the perforation heating element R1 has a length of 170 mm. μm × width 100μ
The size of m, and the heat-generating heating element R2 is 70 μm in length × width
As shown in the figure, the surface of the heat-sensitive stencil sheet has a resin layer in an area corresponding to the heat-generating body R1 for perforation (area located on the heat-generating body R1). The temperature is higher than the melting point of the resin forming 9 and is higher than the glass transition point of the resin forming the resin layer 9 over a wide area including the heating element R1 for perforation and the heating element R2 for heat retention.

As described above, the heat-sensitive stencil sheet 7 is conveyed in the conveying direction (direction A) with respect to the heat-generating body R1 for perforation of the thermal head.
On the downstream side, a heat retaining heating element R2 having an electric resistance value smaller than that of the perforation heating element R1 is arranged, and the heat generation of the heat retaining heating element R2 causes heat generation from the perforation heating element R1 to the heat retaining heating element R.
By holding the heat-sensitive stencil sheet 7 located up to 2 to a temperature higher than the glass transition point of the resin layer 9 of the base sheet 7, the heat-generating body R1 for perforation is heated to generate the resin layer of the heat-sensitive stencil sheet 7. When the hole 7a is formed in the hole 9, even if the heat-sensitive stencil sheet 7 is conveyed in a predetermined direction and the holed portion is moved to a position slightly apart from the heat-generating body R1 for perforation,
The resin layer 9 melted by the heat from is kept at a temperature higher than the glass transition point by the heat-retaining heating element R2 arranged on the downstream side of the heat-sensitive stencil sheet 7 in the conveying direction (direction A), and the heat-retaining heating element R2. It is not cooled until it is transported to the downstream side of the above. As a result, the resin layer 9 that has been melted by the heat from the heat generating element R1 for punching is heated
1 does not become highly viscous in the vicinity of 1, and the heating element R for perforation
It is possible to effectively prevent the resin from adhering to the vicinity of 1. As a result, the heat-sensitive stencil sheet 7 is made into the perforating heating element R1.
It becomes possible to always run stably while making good contact with the heat sensitive stencil sheet 7, and it is possible to satisfactorily form the desired hole 7a in the heat-sensitive stencil sheet 7.

The reason why the surface temperature of the heat-sensitive stencil sheet 7 heated by the heat retaining heating element R2 is set higher than the glass transition point of the resin layer 9 is that the resin layer 9 is provided with appropriate fluidity. The purpose of this is to effectively prevent the sticking of 9 in the vicinity of the perforation heating element R1 and to lower the melting point of the resin layer 9 to prevent retransfer to the heat-sensitive stencil sheet 16 and unnecessary holes. This is because it is possible to effectively prevent the formation of holes and the shape of the holes becoming vertically long. The surface of each of the heat-generating element R1 for perforation and the heat-generating element R2 for heat retention is covered with a protective film 5 made of silicon nitride, and the protective film 5 causes abrasion due to sliding contact of the heat-sensitive stencil sheet 7 and is contained in the atmosphere. The resistance layer 3 and the conductive layers 4a to 4c are protected from corrosion caused by contact of moisture contained therein and Na ⁺ , Cl ⁻ contained in the resin layer 9 of the heat-sensitive stencil sheet 7.

The thermal plate making apparatus incorporating such a thermal head applies a predetermined electric power to the resistance layer 3 sandwiched between the conductive layers 4a, 4b and 4c of the thermal head based on a print signal from the outside to punch a hole. The heating element R1 and the heating element R2 for heat retention are selectively caused to generate Joule heat, and the generated heat is conducted to the heat-sensitive stencil sheet 7, and a part of the resin layer 9 of the heat-sensitive stencil sheet 7 is melted to perforate the holes 7a. When installed, it functions as a thermal plate-making device.

The heat-sensitive stencil sheet 7 is used, for example, in a stencil printer after the holes 7a are formed as described above, and is used for printing on one main surface side of the heat-sensitive stencil sheet 7. The ink is placed on the other main surface side, and the ink is adhered to the print object through the holes 7a formed in the heat-sensitive stencil sheet 7 so that predetermined characters and images are formed on the print object by printing. ing.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the gist of the present invention. For example, in the above-described embodiment, perforation is provided. Only one heat-generating heating element was provided downstream of the heat-generating stencil sheet in the conveying direction of the heat-sensitive stencil sheet. By providing two or more heat-generating stencil sheets, the glass transition of the resin layer on the surface of the heat-sensitive stencil sheet was performed. The region maintained at a temperature higher than the point may be formed wider.

[0025]

According to the present invention, when the heat-generating element for perforation is heated to form holes in the resin layer of the heat-sensitive stencil sheet, the heat-sensitive stencil sheet is transported and the perforated portion is placed on the heat-generating element for perforation. The resin layer that had been melted by the heat from the heat-generating element for perforation even if moved a little away from is higher than the glass transition point by the heat-generating element for heat retention that is arranged on the downstream side in the transport direction of the heat-sensitive stencil sheet. Hold at temperature. For this reason, the heat-sensitive stencil sheet is not cooled until it is conveyed to the downstream side of the heat retaining heating element, effectively preventing the resin layer of the heat-sensitive stencil sheet from adhering to the vicinity of the perforation heating element. can do. As a result, the heat-sensitive stencil sheet can be always stably run while being brought into close contact with the perforation heating element, and desired holes can be satisfactorily formed in the heat-sensitive stencil sheet.

[Brief description of the drawings]

FIG. 1 is a plan view of a thermal head used in a heat-sensitive plate making apparatus of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a graph showing a temperature state of the heat-sensitive stencil sheet heated by the thermal head of FIG.

FIG. 4 is a sectional view of a thermal head used in a conventional thermal plate making apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Glaze layer 3 ... Resistive layer 4a-4c ... Conductive layer 5 ... Protective film 6 ... Driver IC 7 ... Heat-sensitive stencil base paper 8 ... Porous Support 9 ... Resin layer

Claims (1)

[Claims] 1. A thermal head having a heat-generating element for perforation, wherein a heat-sensitive stencil sheet having a resin layer coated on a porous support is conveyed onto the heat-generating element for perforation of the thermal head and perforated. In the heat-sensitive plate making apparatus that melts the resin layer of the heat-sensitive stencil sheet by heat generated by the heat-generating element to form predetermined holes in the resin layer of the heat-sensitive stencil sheet, the thermal head is a heat-generating element for perforation, of the heat-sensitive stencil sheet. On the downstream side in the conveying direction, a heat retaining heating element having an electric resistance value smaller than that of the perforating heating element is provided, and the perforation heating element to the heat retaining heating element are heated by heating the heat retaining heating element. A heat-sensitive plate making apparatus, characterized in that the heat-sensitive stencil sheet located between the two is held at a temperature higher than the glass transition point of the resin layer of the sheet.