JP2000085257A - Stencil printing base paper and its processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stencil printing base paper of superior uniformity of solid sections, improved in density unevenness and set-off, and superior in resolution of small characters, and provide further its processing method. SOLUTION: A stencil printing base paper is formed of a thermoplastic resin film and a porous substrate composed mainly of thermoplastic fibers laminated together, and when a processing section of 20-50% opening rate is formed on a film, the average air permeability resistance of the processing section of the stencil printing base paper satisfies 0.05-0.15 Kpa.s/m. The wet stencil strength of the base paper is desirably 200 gf/cm or more in one direction. The thermoplastic resin film is desirably composed of polyester film, and thermoplastic fibers are desirably composed of polyester resin. When a number of fine pores corresponding to an image to be printed on the stencil printing base paper are formed and processed, the pores are so formed as to satisfy the condition of 0.05-0.15 Kpa.s/m average filtration resistance of the processing section to form a good image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil sheet and a stencil making method, and more particularly, to flash light irradiation with a halogen lamp, a xenon lamp, a flash bulb or the like, infrared irradiation, pulse irradiation such as a laser beam, or a thermal head. The present invention relates to a stencil sheet which is suitable for heat-sensitive plate making, has excellent printing characteristics, particularly excellent uniformity of a solid portion of a printed image, and has no density unevenness and set-off, and a plate making method thereof.

[0002]

2. Description of the Related Art Conventionally, stencil sheets used for stencil printing include thermoplastic paper films such as polyester films, vinylidene chloride films, and polypropylene films, and thin papers, nonwoven fabrics, and gauze made of a mixture of natural fibers and synthetic fibers. It is known that a porous support is laminated with an adhesive.

However, images printed with these conventional stencil papers have not always been satisfactory in terms of sharpness, particularly the uniformity of solid portions. There are various reasons why the clarity of the printed image is not enough,
When a thin paper made of natural fibers is used as the porous support,
Since the fiber diameter is relatively large and uneven, the ink permeability tends to be uneven, and the smoothness of the laminated film surface is reduced by the effect of the thick fiber. Contact is poor and unperforated portions are likely to occur. As a result, the image is blurred, and white spots occur in solid portions. Furthermore, in the manufacturing process of the support, the foreign matter derived from the natural fiber is not sufficiently removed, so that there is also a drawback that the passage of the ink is hindered and white spots are generated on the printed image. Further, even when thin paper mixed with natural fibers and synthetic fibers is used as the porous support, the effect is still insufficient. (JP-A-59-2896, JP-A-59-1679)
3 and JP-A-2-67197. )

A stencil sheet in which a nonwoven fabric made of synthetic fiber is bonded to a film has also been proposed. However, density unevenness called "fiber mesh" occurs, and the strength of the base paper cannot be sufficiently secured, so that it has not been put to practical use. . (JP-A-2-67197
Reference, JP-A-5-309967 and the like. )

Further, a stencil sheet is proposed in which a porous support made of an unstretched thermoplastic resin fiber is thermocompression-bonded to an unstretched thermoplastic resin film and then biaxially stretched so as to be laminated without using an adhesive. Have been. Then, in such a stencil sheet, by using a porous support that satisfies a specific aperture area fraction and a specific aperture average diameter,
It has been proposed to improve the sharpness and set-off of printed images. (See JP-A-7-205564)

However, even in this case, depending on the fiber distribution in the cross-sectional direction of the support, the uniformity of the solid portion is still insufficient, and set-off may occur. Further, during printing, when the printing paper is peeled from the drum, the base paper may expand and contract to cause density unevenness.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and provides excellent uniformity of a printed image, particularly, a solid portion, improved density unevenness and set-off, and improved fine character resolution. It is another object of the present invention to provide an excellent stencil sheet and a stencil making method.

[0008]

Means for Solving the Problems In order to achieve the above-mentioned object, the present inventor has focused on the mechanism when ink passes through the base paper, and as a result, has studied the distribution of fibers in the plane direction of the support. In addition, it has been found that the ink permeability of the base paper should be taken into consideration in consideration of the distribution in the cross-sectional direction, that is, in consideration of the three-dimensional distribution of the fibers of the support. Furthermore, it has been found that by focusing on the strength of the base paper, an excellent printed image without defects can be obtained as compared with the prior art.

That is, according to the present invention, the average airflow resistance of the stencil sheet of the stencil sheet is 0.05 to 0.15 Kpa · s / m, preferably
0.06-0.14Kpas / m, more preferably 0.07-0.12Kpas
At / m, the ink passes well through the perforations in the plate making section. If the average airflow resistance is lower than 0.05 Kpa · s / m, the amount of ink passing through becomes excessive, causing problems such as set-off and rubbing during printing. On the other hand, if the average airflow resistance is higher than 0.15 Kpa · s / m, a portion through which ink does not pass is generated, which causes white spots during printing, which is not preferable. Here, if the opening ratio of the plate making section is 20 to 50%, preferably 29 to 45%,
The ink that has been transferred to the printing paper through the perforations in the plate making
The original is faithfully reproduced as a stencil image in which dense pixels are formed and the density is uniform. In particular, solid portions are reproduced without white spots. If the aperture ratio is less than 20%, a large number of unperforated portions are generated, and the portion through which ink does not pass becomes extremely large, regardless of the density of the support, the dispersion state of the fibers, the density, and the thickness. In this case, white spots are caused, which is not preferable. On the other hand, if the opening ratio is higher than 50%, the ink easily passes through regardless of the dense / dense state, the dispersed state of the fiber, the density, and the thickness, and undesirably causes set-off in the printed matter.

Thus, according to one aspect of the present invention, there is provided a stencil sheet formed by laminating a thermoplastic resin film and a porous support mainly composed of thermoplastic fibers, wherein the film has an aperture ratio of 20 to When a 50% stencil sheet is formed, the stencil sheet is provided, wherein the average airflow resistance of the stencil sheet satisfies 0.05 to 0.15 Kpa · s / m.

According to another aspect of the present invention, a stencil sheet formed by laminating a thermoplastic resin film and a porous support mainly composed of a thermoplastic fiber is used for an image to be printed. A stencil making method for making a stencil sheet by performing a number of fine perforations on the film to make a stencil, wherein the stencil making part is stenciled so that an average airflow resistance satisfies 0.05 to 0.15 Kpas / m. A stencil sheet making method is provided.

According to still another aspect of the present invention, an image to be printed is formed using a stencil sheet formed by laminating a thermoplastic resin film and a porous support mainly composed of thermoplastic fibers. A stencil making method for making a stencil sheet by making a corresponding number of fine perforations in said film, wherein said stencil making section is made so as to have an aperture ratio of 29 to 45%. Is provided.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The stencil paper of the present invention is obtained by laminating a thermoplastic resin film and a porous support mainly composed of thermoplastic fibers.

Examples of the thermoplastic resin film in the present invention include conventionally known films made of polyester, polyamide, polypropylene, polyethylene, polyvinyl chloride, polyvinylidene chloride or a copolymer thereof. A polyester film is preferred from the viewpoint.

The thermoplastic fibers in the present invention include, for example, conventionally known fibers made of polyester, polyamide, polyphenylene sulfide, polyacrylonitrile, polypropylene, polyethylene or a copolymer thereof. Polyester fibers are preferred in terms of stability.

The polyester constituting the polyester film and the polyester fiber in the present invention is polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, a copolymer of ethylene terephthalate and ethylene isophthalate, polyethylene-2, Examples thereof include 6-naphthalate, polyhexamethylene terephthalate, and a copolymer of hexamethylene terephthalate and 1,4-cyclohexane dimethylene terephthalate.

The thermoplastic resin film in the present invention is preferably stretched, and particularly preferably biaxially stretched. Such a stretched film, for example, to produce an unstretched film by extruding a polymer onto a cast drum by a conventionally known T-die extrusion method,
Next, the film can be produced by longitudinal stretching by a group of heating rolls and, if necessary, by supplying it to a tenter or the like and transversely stretching. Cap slit width, polymer discharge rate,
By adjusting the rotation speed of the cast drum, an unstretched film having a desired thickness can be produced. In addition, by adjusting the rotation speed of the heating roll group or changing the set width of the tenter, stretching can be performed at a desired stretching ratio.

In the present invention, the thickness of the thermoplastic resin film is appropriately determined depending on the required sensitivity and the like.
It is usually 0.1 to 10 μm, preferably 0.1 to 5 μm, more preferably 0.1 to 3 μm. If the thickness exceeds 10 μm, the piercing property may decrease, and if the thickness is less than 0.1 μm, the film formation stability may deteriorate.

The porous support in the present invention may be papermaking paper, nonwoven fabric, woven fabric, or screen gauze made of a single fiber made of the above thermoplastic fiber. A nonwoven fabric is preferred from the viewpoint.

In the present invention, the average fiber diameter of the porous support is preferably 2 to 10 μm. Average fiber diameter is 2μ
If it is less than m, wrinkles easily enter the base paper and unperforated at the time of perforation, which is not preferable. On the other hand, when the thickness exceeds 10 μm, unevenness in ink passage occurs, which is not preferable.

In the present invention, the density of the porous support is
0.1 g / m ^{3 to} 0.2 g / m ³ , preferably 0.12 g / m ³ to
More preferably, it is 0.17 g / m ³ . The density of the support can be arbitrarily adjusted depending on the fiber diameter and processing conditions such as drawing and heating. At this time, if it is 0.1 g / m ³ or less, the amount of ink passing through becomes excessive, and problems such as set-off and rubbing during printing occur. On the other hand, if it is 0.2 g / m ³ or more, a portion through which ink does not pass is generated, which causes white spots during printing, which is not preferable.

In the present invention, the basis weight of the porous support is preferably 1 to 30 g / m ² , more preferably ² to 30 g / m 2.
20 g / m ^2, particularly preferably 3~16g / m ^2.

The nonwoven fabric used as the porous support of the present invention can be produced by a conventionally known direct melt spinning method such as a melt blow method or a spun bond method. In the melt blow method, the nonwoven fabric, when discharging the molten polymer from the die, by blowing hot air from the peripheral portion of the die, and finely polymerized by the hot air,
It is manufactured by spraying and collecting on a net conveyor arranged at a predetermined position to form a web. Since the web is sucked together with the hot air by the suction device provided on the net conveyor, the individual fibers are collected before they are completely solidified. That is, the fibers of the web are collected in a fused state. By appropriately adjusting the collection distance between the base and the net conveyor, the degree of fusion of the fibers can be adjusted. Also, by appropriately adjusting the polymer discharge amount, hot air temperature, hot air flow rate, conveyor moving speed, etc.,
Web weight and single yarn fiber diameter can be arbitrarily set. The fiber spun by the melt blow method is finely fined by the pressure of hot air and solidified in a non-oriented or low-oriented state. The thickness of the fibers is not uniform, and the web is formed in a state where the thick fibers and the thin fibers are appropriately dispersed. Further, the polymer discharged from the die is rapidly cooled from a molten state to a room temperature atmosphere, so that the polymer is solidified in a low-crystalline state close to an amorphous state.

The non-woven fabric constituting the porous support of the present invention is preferably stretch-oriented, and the birefringence (Δn) of each fiber is preferably 0.1 or more, more preferably 0.1.
It is 12 or more, particularly preferably 0.14 or more. The crystallinity of the fiber is preferably at least 15%, more preferably at least 20%, particularly preferably at least 25%.

In the present invention, the thermoplastic resin film and the porous support may be laminated by using an adhesive under the condition that the perforation sensitivity of the film is not reduced. It is preferred that the layers are laminated by thermal fusion without any intervening. The peel strength between the film and the support is preferably 3 g / cm or more, more preferably 5 g / cm or more, and particularly preferably 10 g / cm or more.

The heat fusion can be achieved, for example, by thermocompression bonding the unstretched film and the unstretched nonwoven fabric before the longitudinal stretching step obtained by extrusion casting, with a heating roll. The fusion temperature is usually preferably between the glass transition temperature (Tg) and the melting point (Tm) of the thermoplastic resin film, more preferably the glass transition temperature (Tg) and the cold crystallization temperature (Tcc). In the case of a polyester film, the temperature is preferably in the range of Tg + 10 ° C. to Tg + 50 ° C.

In the present invention, it is particularly desirable that the non-stretched thermoplastic film and the nonwoven fabric are heat-sealed and then co-stretched. By co-stretching in the state of heat fusion,
The film and the nonwoven fabric can be preferably stretched without being peeled off integrally. At this time, the nonwoven fabric is fused to each other at the entanglement points and the contact points to form a mesh having the contact points.

The polyester non-woven fabric used for heat fusion is most preferably unstretched, but even if stretched, it is preferably one having a low magnification and a low degree of orientation. In this state, the birefringence (Δn) of the fibers of the nonwoven fabric is preferably 0.1.
03 or less, more preferably 0.02 or less, particularly preferably 0.01
And the crystallinity is preferably 20% or less, more preferably 15% or less, and particularly preferably 10% or less.

The method of co-stretching is not particularly limited, but biaxial stretching is preferred, and any of a sequential biaxial stretching method and a simultaneous biaxial stretching method may be used. In the case of the successive biaxial stretching method, stretching is generally performed in the order of the longitudinal direction and the transverse direction, but may be performed in the reverse order. The stretching temperature is preferably between the glass transition temperature (Tg) and the cold crystallization temperature (Tcc) of the thermoplastic resin film. The stretching ratio is not particularly limited, and is appropriately determined depending on the type of the polymer constituting the thermoplastic resin film, the sensitivity required for the base paper, and the like.
88 times, more preferably 3 to 8 times.

After the co-stretching, the base paper is preferably subjected to a heat treatment, usually at 80 to 260 ° C. for about 0.5 to 60 seconds.

In the present invention, non-woven fabrics having different or the same kind of fiber diameter and basis weight may be stretched by multi-layer superposition.

In the present invention, the stencil sheet can be stenciled by any means capable of forming a number of fine perforations corresponding to the image to be printed in the thermoplastic resin film. Flash irradiation, infrared irradiation with a halogen lamp, xenon lamp, flash valve, etc.
Alternatively, it is suitable for thermal plate making using a thermal head or the like. When using the stencil sheet of the present invention as a heat-sensitive stencil sheet, the melting point of the thermoplastic resin film (Tm ₁₎ the melting point of the porous support (Tm _2), it is preferable that the Tm ₁ ≦ Tm _2.

In the present invention, in order to realize the aperture ratio of the base paper of 20 to 50%, for example, when a thermal head is used for plate making means, the temperature and area applied to the film depend on the element size, the pitch between the elements and the input energy. May be appropriately adjusted.

In the present invention, it is preferable to provide a release layer on the surface of the thermoplastic resin film opposite to the porous support side in order to prevent fusion with plate making means such as a thermal head. The release layer may be formed at any stage before or after the film is stretched, but it is preferable to apply the film before the stretching in order to more remarkably exert the effects of the present invention. As the release agent, one composed of silicone oil, silicone resin, fluorine resin, surfactant or the like can be used. The release layer can be formed by applying a coating material containing such a release agent using a coating means such as a roll coater, a gravure coater, a reverse coater, or a bar coater. Various additives such as a dispersing aid, a surfactant, a preservative, and an antifoaming agent may be added to the coating composition for the purpose of improving the dispersibility of the release agent in a medium such as water.
The thickness of the release layer is preferably 0.005 μm or more and 0.4 μm or less,
More preferably, the thickness is 0.01 μm or more and 0.4 μm or less. When the thickness of the release agent is 0.4 μm or less, the running property at the time of perforation is good, and the contamination of the thermal head is small.

Further, the base paper of the present invention may contain various additives such as an antistatic agent as long as the effects of the present invention are not impaired.
Heat-resistant agents, antioxidants, organic particles, inorganic particles, pigments and the like may be contained.

When stencil printing is performed using the stencil sheet of the present invention, the ink used is preferably a water-in-oil (W / O) emulsion ink. The W / O emulsion ink comprises, for example, about 10 to 70% by weight of an oil phase and about 90 to 30% by weight of an aqueous phase. Further, a colorant is contained in the oil phase or the aqueous phase, and the amount of the colorant is 1 to 30% by weight based on the total amount of the emulsion ink.
More preferably, it is 3 to 10% by weight. The average particle size of the colorant is preferably in the range of 0.1 to 12 μm. The particle size is
If it is smaller than 0.1 μm, even if the ink passes through the base paper, the coloring agent easily penetrates into the inner layer of the printing paper, and a satisfactory printing density cannot be obtained. Conversely, when the particle size is 12
If it is larger than μm, the colorant is liable to cause clogging between the fibers of the support of the base paper, and it is not preferable because white spots are formed on the printed matter.

The stencil sheet of the present invention preferably has a wet tensile strength in at least one direction of at least 200 gf / cm, more preferably at least 250 gf / cm, particularly preferably at least 300 gf / cm. is there. Here, the wet tensile strength is the tensile strength when the porous support surface of the stencil paper is impregnated with water, and when used, the direction satisfying the wet tensile strength is the longitudinal direction, that is, the base paper is supplied to the printing press. It is preferable to set the traveling direction in this case. The strength is
If it is lower than 200 gf / cm, the strength at the time of printing is not sufficient, and when the printing paper peels from the drum, the base paper expands and contracts, causing uneven release, resulting in uneven density in the printed image. May appear. On the other hand, when the strength is 300 gf / cm or more, the strength of the stencil paper is secured, and no expansion or contraction occurs at the time of release, and stable printing performance without density unevenness is obtained.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments, but the present invention is not limited to only the embodiments. First, methods for measuring and evaluating the characteristics of the stencil paper used in the following examples will be described.

(1) Average airflow resistance A black solid manuscript having a printing rate of 100% was stencil-produced by a rotary stencil printing machine RISOGRAPH (registered trademark) GR377 manufactured by Riso Kagaku Kogyo KK to prepare a master. Next, the master plate making section was cut into a size of 10 cm × 10 cm, and measured with a “breathability tester (KES-F8-API manufactured by Kato Tech Co., Ltd.)” in a measuring area of 30 mm in diameter (φ). Was done. The measurement was repeated five times, and the average value was defined as the average airflow resistance.

(2) Wet tensile strength of base paper The base paper was cut in the longitudinal direction (ie, in the transport direction in the printing press), and a sample having a width of 1.5 cm and a length of 10 cm was collected. The sample was immersed in water so that it would fit well, and pulled with a universal testing machine (Shimadzu Autograph AGS-D type) at a test speed of 10 mm / min until the sample ruptured. And the strength was determined.

(3) Measurement of the opening ratio of the plate making part The base plate made in the above step (1) was photographed using an optical microscope, and the perforated part was scanned with a scanner (HEWLETT PACKARD).
After reading by Scanjet 4C) and performing binarization processing, the perforated area was determined and the aperture ratio was calculated.

(4) Measurement of Support Fiber Diameter Photographs were taken at 10 arbitrary locations on the nonwoven fabric sheet of the stencil paper with an electron microscope, and for each photograph, the diameter of 15 arbitrary fibers was measured. A total of 150 fiber diameters were measured, and the average value was determined.

(5) Measurement of the basis weight of the support The stencil paper was cut into 210 × 297 mm, and its weight was measured and converted per m ² . The weight of the film was subtracted therefrom to obtain the basis weight.

(6) Measurement of base paper thickness Ten base papers are superimposed and PEACOCK (DIAL THICKNESS GAUG
E; Ozaki Manufacturing Co., Ltd.). And one
The thickness per sheet was calculated.

(7) Evaluation Method of Printed Material Plate making and printing were performed by RISOGRAPH (registered trademark) GR377, a rotary stencil printing machine manufactured by Riso Kagaku Kogyo Co., Ltd. that time,
As the original, an original having a printing rate of 100% in a completely solid state, and an original having a printing rate of 25% in which characters of 6 points to 10.5 points and a solid portion were mixed were used. Solid uniformity and density unevenness were evaluated on a document with a printing rate of 100%, and fine character resolution and set-off were evaluated on a document with a printing rate of 25%.

Example 1 Using a rectangular die having a hole diameter of 0.35 mm and 80 holes, the die temperature was set to 285 ° C., and the polyethylene terephthalate raw material (η
= 0.60, Tm = 254 ° C) by melt blow method.
The fibers are dispersed and collected on a conveyor, and the average fiber diameter is 8.0μ.
m, and a nonwoven fabric having a basis weight of 110 g / m ² was prepared.

Next, a raw material of a copolymer polyester resin composed of 85 mol% of polyethylene terephthalate and 15 mol% of polyethylene isophthalate (η = 0.65, Tm = 225)
C.) using a 40 mm screw diameter extruder at a T-die die temperature of 275 ° C., and cast on a cooling drum to produce an unstretched film. Then, the nonwoven fabric was superimposed on the unstretched film, supplied to a heating roll, and thermocompression-bonded at a roll temperature of 80 ° C. to produce a laminated sheet.

After the laminated sheet is stretched three times in the flow direction between the heating rolls, it is sent to a tenter-type stretching machine, and then stretched three times in the width direction, and further heat-treated at 140 ° C. in a tenter. Was prepared.

The base paper thus obtained has a film thickness of 1.
5 μm, average fiber diameter of support 4.0 μm, basis weight 9.7 g /
m ² and the thickness of the base paper were 76 μm. Further, in order to have a releasability from the thermal head, the base paper was coated with silicone oil by a roll coater so as to have a thickness of 0.01 μm.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results.

Example 2 A stencil sheet was produced in the same manner as in Example 1 except that the nonwoven fabric having an average fiber diameter before stretching of 9.5 μm was used. The base paper thus obtained has a film thickness of 1.5 μm,
The average fiber diameter of the support was 4.75 μm, the basis weight was 9.7 g / m ² , and the thickness of the base paper was 75.0 μm.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results.

Example 3 A stencil sheet was produced in the same manner as in Example 1, except that the nonwoven fabric had an average fiber diameter before stretching of 10.5 μm and a basis weight of 90 g / m ² . The base paper thus obtained has a film thickness of 1.6 μm, an average fiber diameter of the support of 5.2 μm, and a basis weight.
The thickness of the base paper was 8.1 g / m ² and the base paper thickness was 65.0 μm.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results.

Example 4 A stencil sheet was produced in the same manner as in Example 1 except that the nonwoven fabric having a basis weight before stretching of 90 g / m ² was used.
The base paper thus obtained had a film thickness of 1.3 μm, an average fiber diameter of the support of 5.0 μm, a basis weight of 11.5 g / m ² , and a base paper thickness of 87.3 μm.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results.

Example 5 A stencil sheet was prepared in the same manner as in Example 1 except that a nonwoven fabric having an average fiber diameter before stretching of 7.0 μm and a basis weight of 103 g / m ² was used. The base paper thus obtained has a film thickness of 1.6 μm, an average fiber diameter of the support of 3.4 μm, and a basis weight.
The base paper had a thickness of 8.6 g / m ² and a thickness of 60.0 μm.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results.

Example 6 A stencil sheet was prepared in the same manner as in Example 1 except that the nonwoven fabric having a basis weight before stretching of 130 g / m ² was used.
The base paper thus obtained had a film thickness of 1.6 μm, an average fiber diameter of the support of 3.4 μm, a basis weight of 12.0 g / m ² , and a base paper thickness of 89.6 μm.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results.

Example 7 The average fiber diameter obtained by the same spinning method as in Example 1 was 6.6 μm.
m, a nonwoven fabric with a basis weight of 90 g / m ² and an average fiber diameter of 16 μm,
A nonwoven fabric having a basis weight of 30 g / m ² was laminated on each other, the nonwoven fabric was laminated on the film so that the former nonwoven fabric was in contact with the film, and co-stretched in the same manner as in Example 1 to produce a stencil sheet. The base paper thus obtained has a film thickness of 1.5μ.
m, the average fiber diameter of the first layer support is 3.3 μm, and the basis weight is 8.2.
g / m ² , the average fiber diameter of the second layer support was 8.0 μm, the basis weight was 2.7 g / m ² , and the thickness of the base paper was 83 μm.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results.

Comparative Example 1 In the stretching method of Example 1, a single film was stretched in advance to a film thickness of 1.7 μm to produce a film.
And, the basis weight obtained by mixing natural fibers and synthetic fibers is 10.5
At 5 g / m ² , a 59.0 μm-thick support was laminated with an adhesive to produce a stencil sheet.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results. As shown in Table 1, white spots appeared on solid portions of the printed matter, and the image quality was insufficient.

Comparative Example 2 According to the method of Example 1, the film thickness was 1.3 μm, the average fiber diameter of the support was 5.0 μm, the basis weight was 9.0 g / m ² , and the thickness of the base paper was 3
A stencil sheet of 9.6 μm was produced.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results. As shown in Table 1, due to insufficient strength of the base paper, uneven density occurs due to uneven transfer of horizontal stripe-shaped ink on the printed matter, and the ink passage resistance is too low because the passage resistance of the ink is too low.
Set-off has occurred.

Comparative Example 3 According to the method of Example 1, the film thickness was 1.3 μm, the average fiber diameter of the support was 6.1 μm, the basis weight was 9.8 g / m ² , and the thickness of the base paper was 4
A stencil sheet of 2.2 μm was produced.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results. As is clear from Table 1, similarly to Comparative Example 2, density unevenness occurred in the printed matter, and set-off occurred.

Comparative Example 4 According to the method of Example 1, the film thickness was 2.7 μm, the average fiber diameter of the support was 4.3 μm, the basis weight was 17.9 g / m ² , and the thickness of the base paper was
A stencil sheet of 105 μm was produced.

This base paper was subjected to the measurement and evaluation methods described above. Table 1 shows the results. As is evident from Table 1, since the passage resistance of the ink was too high, an image having many white spots was obtained, and the resolution of fine characters was low.

[0071]

[Table 1]

Evaluation criteria ◎: extremely good ：: good Δ: no problem in practical use ×: impractical

As can be seen from Table 1, when the aperture ratio of the stencil sheet obtained by the stencil making is 20 to 50%, by setting the average airflow resistance of the stencil making part to 0.05 to 0.15 Kpa · s / m,
It can be seen that an image with no white spots and set-off and excellent in fine character resolution can be obtained. Further, when the wet strength of the base paper in the longitudinal direction is 200 gf / cm or more, uneven transfer of the ink is prevented, and uneven density is also reduced. Further, it is understood that the aperture ratio of the plate making section is preferably set to 29 to 45%.

[0074]

According to the present invention, ventilation that includes not only the distribution of fibers in the plane direction of the support but also the depth (three-dimensional) state of the ink permeability in the stencil part of the stencil paper. Since the concept of resistance is used, it is possible to provide a high-quality printed image that is excellent not only in solid image quality but also in fine character resolution and has no set-off.

Continued on front page F-term (reference) 2H084 AA11 BB04 CC09 2H114 AB22 BA05 DA56 DA76 EA04 FA02 4F100 AK01A AK01B AK42A AK42B BA02 BA16 BA33 DC11 DC11A DC11B DG00B EA061 EC012 EH012 EJ192 EJ372J02J02J02J02A02

Claims (7)

[Claims] 1. A stencil sheet obtained by laminating a thermoplastic resin film and a porous support mainly composed of thermoplastic fibers, wherein a stencil sheet having an aperture ratio of 20 to 50% is formed on the film. , The average ventilation resistance of the plate making part is 0.05 ~ 0.15Kpa
stencil paper characterized by satisfying / m. 2. The wet tensile strength is 200 g in one direction.
2. The stencil sheet according to claim 1, wherein the stencil sheet is at least f / cm. 3. The stencil sheet according to claim 1, wherein the thermoplastic resin film is a polyester resin film. 4. The stencil sheet according to claim 1, wherein the thermoplastic fiber comprises a polyester resin. 5. Using a stencil sheet in which a thermoplastic resin film and a porous support mainly composed of thermoplastic fibers are laminated, a large number of fine perforations corresponding to an image to be printed are formed on the film. A stencil making method for making and making a stencil, wherein the stencil making section has an average airflow resistance of 0.05 to 0.15 Kp.
A method of making a stencil sheet, wherein the stencil sheet is made to satisfy a · s / m. 6. The stencil making method according to claim 5, wherein an aperture ratio of the stencil making section is 20 to 50%. 7. Using a stencil sheet in which a thermoplastic resin film and a porous support mainly composed of thermoplastic fibers are laminated, a large number of fine perforations corresponding to an image to be printed are formed on the film. A stencil making method for stencil making and stencil making, wherein the stencil making part is made so as to satisfy an opening ratio of 29 to 45%.