JPH0858261A - Stencil paper for thermal screen printing and production thereof - Google Patents

Abstract

PURPOSE: To obtain a stencil paper for thermal screen printing excellent in image sharpness and low in production cost without using an adhesive at all. CONSTITUTION: In stencil paper fo.r thermal screen printing consisting of a polyester film layer and a porous support layer composed of a polyester fiber formed into a reticulated structure wherein fibers are mutually fused at the contact points thereof, the polyester fiber forming the porous support layer has a core-sheath structure and the porous support layer has pleats at fused parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive stencil printing base paper which is perforated by a halogen lamp, a xenon lamp, a flash bulb or the like for flash or infrared irradiation, pulsed irradiation of a laser beam or the like, or a thermal head. The present invention relates to a manufacturing method.

[0002]

2. Description of the Related Art Conventionally, as a base paper for heat-sensitive stencil printing,
A thermoplastic resin film such as a polyester film, a vinylidene chloride film, or a polypropylene film is attached to a porous support made of natural fiber, chemical fiber or synthetic fiber, or thin paper, non-woven fabric, gauze or the like made of these fibers with an adhesive. Those having a different structure are known (for example, JP-A-51-2512 and JP-A-57-152).
182495).

However, these conventional heat-sensitive stencil printing base papers have the following drawbacks. That is, (1) since the film and the porous support are bonded together by using an adhesive, the adhesive impedes the transmission of ink, resulting in poor image clarity.

(2) Also, regarding the adhesive itself used, for example, acrylic resin and vinyl acetate resin adhesives are easily softened, swelled and dissolved by printing ink, so that they have poor ink resistance and are heat-cured. When a heat-sensitive adhesive is used, the uncured material is likely to remain, so that the thermal head is likely to cause fusion during plate making.When a chlorine-based adhesive is used, the thermal head heats the poisonous chlorine. There is a problem such as releasing.

(3) Since the film is thin, problems such as film tears and wrinkles are likely to occur during the bonding process.

(4) Furthermore, when an adhesive is used, an adhesive step is required in the manufacturing process of the base paper, and a solvent is used when the adhesive is applied, so a solvent recovery facility is required. Cost increases, and the work environment deteriorates.

In order to improve these drawbacks, it has been proposed to use as little adhesive as possible (for example, JP-A-58-147396 and JP-A-4).
However, the current situation is that the above drawbacks have not been completely eliminated.

As a method without using an adhesive, in Japanese Patent Laid-Open No. 4-212891, there is formed a fiber layer formed by spraying synthetic fibers on one surface of a thermoplastic resin film and thermocompression bonding. A heat-sensitive stencil sheet has been proposed. However, this method is
Since the synthetic fibers of 0 mm or less are scattered by wind force or static electricity, the fibers are non-uniformly dispersed, resulting in uneven ink permeability and insufficient image clarity. Further, in this method, since the adhesiveness between the resin film and the fiber layer is not always sufficient, there is a problem that wrinkles and tears are likely to occur during film transport. In order to complete the adhesiveness, mix the binder fiber into the fiber layer,
Although it has been proposed to apply a small amount of an adhesive to the film surface, the use of binder fibers or adhesives has a drawback in that the ink permeability is impaired, resulting in a decrease in image clarity. To eliminate such drawbacks,
At present, there is a demand for a heat-sensitive stencil printing base paper that does not use an adhesive or a binder at all.

On the other hand, Japanese Patent Application Laid-Open No. 61-276048 proposes a mesh fabric for a printing screen, which comprises a core-sheath type composite filament having a sheath component having good adhesiveness and a core component having good dimensional stability. However, this method is also expensive because it is made into a mesh fabric and then combined with a film. Furthermore, there is a problem that wrinkles and tears tend to occur when pasting with the film,
It was not always satisfactory.

[0010]

SUMMARY OF THE INVENTION The present invention solves the above problems and integrates a film and a porous support without using an adhesive as another component to obtain an image sharpness. The present invention is intended to provide a heat-sensitive stencil printing base paper which is excellent in manufacturing cost and is inexpensive.

[0011]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have carried out thermocompression bonding of a specific polyester film and a porous support made of a polyester fiber non-woven fabric. The inventors have found that by biaxially stretching both of them together, a heat-sensitive stencil printing base paper can be produced all at once without using an adhesive as another component, and have reached the present invention.

The base paper for heat-sensitive stencil printing of the present invention which achieves the above object has the following constitution.

That is, there is provided a heat-sensitive stencil printing base paper comprising a polyester film layer and a porous support layer made of a polyester fiber formed by forming a net body in which fibers are fused to each other at their contact points. In the heat-sensitive stencil printing paper, the polyester fiber forming the support layer has a core-sheath structure and has a fold in the fused portion.

The method for producing a heat-sensitive stencil printing base paper of the present invention has the following constitution.

That is, an unstretched polyester film and a nonwoven fabric made of unstretched polyester fiber having a core-sheath structure whose sheath component has a lower melting point than the polyester film are thermocompression-bonded and then biaxially stretched. This is a method for producing a stencil printing base paper.

The present invention will be described in detail below.

The polyester used for the film and fiber in the present invention is a polyester containing an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid and a diol as main constituent components. Although not particularly limited, from the viewpoints of film forming properties of the film, yarn forming properties and physical properties of the fiber, and sensitivity and thermal dimensional stability when perforating the base paper, cost, etc., for example, terephthalic acid, isophthalic acid, adipic acid, etc. Acid component, ethylene glycol, 1,3-butanediol,
Examples include diol components such as 2,2'bis (4'-β-hydroxyethoxyphenyl) propane. These components can be used as a copolymer of two or more types due to the design of the melting point of the polymer. Further, a part of oxy acid such as hydroxybenzoic acid may be copolymerized.

The above-mentioned polyester can be produced by a conventionally known method. For example, a method in which an acid component is directly esterified with a diol component and then the product of this reaction is heated under reduced pressure to polycondense while removing the excess diol component, or a dialkyl as the acid component There is a method in which an ester is used, an ester exchange reaction is carried out between the ester and a diol component, and then polycondensation is carried out in the same manner as described above. At this time, if necessary,
As the reaction catalyst, conventionally known alkali metals, alkaline earth metals, manganese, cobalt, zinc, antimony, germanium, titanium compounds and the like can be used. Also,
If necessary, a flame retardant, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, an organic lubricant such as a pigment, a dye, a fatty acid ester or wax, or an antifoaming agent such as polysiloxane may be added. it can.

Furthermore, slipperiness can be imparted depending on the intended use (particularly for the polyester forming the film layer). The method for imparting slipperiness is not particularly limited, but examples thereof include clay, mica, titanium oxide, calcium carbonate, kaolin, talc, inorganic particles such as wet or dry silica, organic particles containing acrylic acid, styrene and the like as constituent components. And the like, and a method of so-called internal particles in which a catalyst or the like added during the polyester polymerization reaction is precipitated.

The polyester film layer constituting the base paper for heat-sensitive stencil printing of the present invention is preferably a biaxially stretched film from the viewpoint that the strength as the base paper for heat-sensitive stencil printing can be secured and a uniform film can be obtained. The thickness of the film is appropriately determined depending on the sensitivity required for the heat-sensitive stencil printing base paper and the like, but is preferably 0.1 to 10 μm from the viewpoint of improving the perforation property and securing the film-forming stability, More preferably, it is 0.3 to 5 μm.

Next, it is important that the porous support constituting the base paper for heat-sensitive stencil printing of the present invention is made of polyester fiber and has a core-sheath structure. that is,
For example, it is possible to melt a plurality of polymers from a composite spinning machine, measure a predetermined amount of each with a gear pump, and discharge the polymer from a core-sheath composite spinneret.

The porous support layer is preferably a polyester non-woven fabric, more preferably a polyester long-fiber non-woven fabric. In that case, the basis weight of the nonwoven fabric, from the viewpoint of retaining the uniform and to improve the image clearness and strength permeability of the ink is preferably from 2 to 20 g / m ^2, at 5 to 15 g / m ² More preferably.

The sheath component of the fibers forming the porous support is
It is preferable that the component has good adhesiveness to the polyester film. Specific examples include low crystalline polymers, polymers having a glass transition temperature or a cold crystallization temperature close to those of the polyester film layer, hygroscopic polymers having a lower softening point, and the like. The melting point of the sheath component is preferably lower than the melting point of the film, from the viewpoint of improving the adhesiveness of the film and the adhesiveness between the porous support and the film to improve the morphological stability of the base paper, It is more preferable that the melting point is lower than 0 ° C.

The ratio of the sheath component in the fiber is from the viewpoint of improving the spinnability and the adhesiveness with the film layer.
It is preferably 5% by weight or more, and more preferably 10% by weight. On the other hand, from the viewpoint of maintaining the strength as a porous support and improving the heat resistance when punching the heat-sensitive stencil sheet, the ratio of the sheath component in the fiber is 70.
It is preferably not more than 40% by weight, more preferably not more than 40% by weight.

The monofilament fineness of the fiber forming the porous support layer is preferably 0.3 to 10 denier from the viewpoint of making ink permeability uniform and maintaining strength. In the present invention, all the fibers forming the porous support may have the same fineness, or fibers having different fineness may be mixed. Further, it may have a multi-layer structure in which fibers having different fineness are laminated stepwise.

Next, the porous support layer which constitutes the heat-sensitive stencil printing base paper of the present invention is made of polyester fibers which form a network in which fibers are fused to each other at their contact points. Further characteristically, the portion where the fibers are fused together forms a fold. The folds are present in the form of a thin film between the fused fibers. By having the fused portion formed by forming the folds, the strength of the support can be stabilized, and a uniform opening form can be formed, and the heat sensitivity is well balanced between the retention of the printing ink and the permeability. It can be used as a stencil printing base paper.

In the present invention, the fusion point formed by forming such a fold maintains the strength as a support on the average surface of the support and makes the shape of the openings of the support uniform, and the ink is formed. From the viewpoint of ensuring the retention of the above and preventing the show-through of the printed image, the number is preferably 10 or more, and more preferably 100 or more per 1 mm ² .

Next, a method for producing the heat-sensitive stencil printing base paper of the present invention will be described.

First, the film layer constituting the base paper for heat-sensitive stencil printing of the present invention comprises first using polyester,
An unstretched film is produced by a conventionally known method. For example, an unstretched film can be produced by extruding a molten polyester polymer by a T-die extrusion method onto a cast drum. By adjusting the slit width of the die, the discharge amount of the polymer, and the rotation speed of the cast drum, an unstretched film having a desired thickness can be obtained.

Next, the porous support constituting the base paper for heat-sensitive stencil printing of the present invention is prepared by first melting the melted polyester polymer into a plurality of polymers from a composite spinning machine.
A gear pump measures each predetermined amount and discharges it from the core-sheath type composite die to obtain an unstretched fiber structure. It is preferably obtained by a conventionally known spunbond method using polyester. That is, a polyester melt-spinning machine generally used melts a polyester polymer, measures a predetermined amount with a gear pump, and discharges it from an orifice mouthpiece. The polymer discharged from the die is pulled by an air ejector, collided with a collision plate to open the fibers, and collected into a conveyor shape to form a web. The basis weight of the web can be arbitrarily set by appropriately setting the web-making width, the polymer discharge amount, and the conveyor speed. The web can be heat-fixed with a heating roll to obtain a nonwoven sheet. The term "heat fixing" used herein means that the sheet is bonded to the extent that it is separated into fibers when the sheet is rubbed and loosened by hand, and the temperature of the heating roll is set to an arbitrary value for pressure bonding. In addition, the take-up speed can be arbitrarily adjusted by appropriately adjusting the pressure and flow rate of the ejector air and the air ejecting part of the ejector, and the crystallinity is different by adjusting the cooling conditions of the discharged polymer. Can take By adjusting these, the physical properties of the fiber can be arbitrarily set.

It is preferable to use a low melting point polymer as the sheath polymer because it facilitates the stretching (hereinafter sometimes referred to as "co-stretching") after the compounding with the unstretched film described later. That is, when the low melting point polymer covers as a sheath, the cooling of the core component at the time of spinning is slowed down, a fiber with higher elongation can be obtained and easily stretched, and the spinning tension is applied to the core component to The oriented crystals of the components are suppressed to a low level, which facilitates adhesion during co-stretching. In addition, the breaking elongation of the unstretched yarn is preferably 250% or more in terms of breaking elongation after the composite with the unstretched film is improved.
It is more preferably 80% or more. On the other hand, since the core component plays a role of supporting and reinforcing the base paper for heat-sensitive stencil printing, it preferably has a higher melting point than the polymer of the film and the sheath component.

The composite of the unstretched film thus obtained and the porous support is carried out by thermocompression bonding in which the film is directly attached while being heated. The method of thermocompression bonding is not particularly limited, but thermocompression bonding with a heating roll is particularly preferable from the viewpoint of processability. The thermocompression bonding in the present invention is preferably performed after the polyester film is formed and before the stretching step. The thermocompression bonding temperature is preferably between the glass transition temperature (Tg) of the film and the cold crystallization temperature, and Tg + 10
C to Tg + 50 ° C. is particularly preferred.

In the present invention, the polyester film and the porous support made of a fibrous nonwoven fabric are co-stretched in a state of being thermocompression bonded. By co-stretching in a thermocompression-bonded state, the film and the support can be suitably stretched as one body without peeling. Further, by co-stretching the both integrally, the polyester fiber serves as a reinforcing body, the film is not torn, and excellent in film forming stability,
As a result, a low-cost heat-sensitive stencil sheet can be obtained.

The stretching method is not particularly limited, but biaxial stretching is preferable from the viewpoint of improving the perforation sensitivity of the film and the uniform dispersibility of the fibers forming the porous support. The biaxial stretching may be either a sequential biaxial stretching method or a simultaneous biaxial stretching method. In the case of the sequential biaxial stretching method, it is general to stretch in the longitudinal direction and then in the transverse direction, but the stretching may be reversed. The stretching temperature is preferably between the glass transition temperature and the cold crystallization temperature of the polyester film. The draw ratio is not particularly limited and may be appropriately determined depending on the type of the polyester film polymer used, the sensitivity required for the heat-sensitive stencil printing base paper, etc.
About 5 times is appropriate. Further, after biaxial stretching, it may be re-stretched longitudinally or laterally or longitudinally and laterally.

Further, the heat-sensitive stencil printing base paper of the present invention after biaxial stretching may be heat-treated. The heat treatment temperature is not particularly limited and may be appropriately determined depending on the type of the polyester film polymer used, but is usually 100 to
It is suitable that the temperature is 240 ° C. and the time is about 0.5 to 60 seconds.

Further, the heat-sensitive stencil printing base paper of the present invention preferably has a release agent layer on the film surface in order to stabilize the running property during perforation. As the release agent, silicone oil, silicone resin, fluorine resin, surfactant,
Conventionally known materials such as petroleum waxes and vegetable waxes can be used, and the coating method is not particularly limited, and they can be coated using a roll coater, a gravure coater, a reverse coater, a bar coater, or the like. Various additives may be used in combination in the above composition within a range that does not impair the effects of the present invention. Examples thereof include antistatic agents, heat-resistant agents, antioxidants, organic particles, inorganic particles and pigments. Further, various additives such as a dispersion aid, a surfactant, a preservative, an antifoaming agent and the like may be added to the coating agent for the purpose of improving dispersibility in water.

[0037]

EXAMPLES The present invention will be described in more detail below with reference to examples. The measuring method used in this example will be described below.

<Melting point (° C.)> A peak of the endothermic curve when 5 mg of a sample was sampled using a differential scanning calorimeter RDC220 type manufactured by Seiko Denshi Kogyo Co., and heated from room temperature at a heating rate of 20 ° C./min. It was calculated from the temperature.

<Single fiber fineness (d; denier)> The single fiber fineness during spinning was measured by the method (1) below, and the single fiber fineness as the heat-sensitive stencil printing base paper was measured by the method (2) below. .

(1) Before forming fibers into a non-woven fabric sheet, long fibers for measurement are taken into blocks and sampled for 10 pieces each having a length of 0.9 m, and each is weighed to obtain the fineness, which is expressed as an average value. did.

(2) An arbitrary 10 spots of the sample were photographed with an electron microscope at a magnification of 500 and 10 photographs were taken, and the diameters of 15 fibers were measured per photograph. The photographs were taken, and a total of 150 fiber diameters were measured. Determine the fineness with a density of 1.38 g / cm ³ ,
The average value is shown.

<Fabric weight (g / m ² )> Test piece 20 cm
A sample of x20 cm was taken, and its weight was measured and converted into a weight per m ² .

<Intrinsic viscosity> Using a mixed solvent of equal weight of phenol and carbon tetrachloride, the sample was measured at 0.5 g / 100 cc and the measurement temperature was 20 ° C. (Yamatrabotic AVM-
10S type automatic viscosity meter).

<Formation and number of folds at fiber fusion points> The sample was observed with a Topcon Scanning Electron Microscope DS130 at a magnification of 300, and the number of fusion points was counted.

<Evaluation of Adhesiveness> The sample was observed with an optical microscope.

<Evaluation of printability> The prepared heat-sensitive stencil printing base paper was supplied to “Lisograph” manufactured by Riso Kagaku Kogyo Co., Ltd.
By the thermal head type plate making method, JIS 1st level characters of 2mm square and 5mm square and 2-10mmφ with black filled circles, and ruled lines with different thickness are used as originals. did.

A printed matter using a plate-making original was visually evaluated for character sharpness, uneven thickness of ruled lines, white spots on solid black portions, and the like.

Example 1 An unstretched polyester fiber non-woven fabric was produced as follows.

As the sheath component, chips of isophthalic acid 25 mol% copolymerized polyethylene terephthalate (intrinsic viscosity = 0.70) having a melting point of 190 ° C. were used after vacuum drying at 140 ° C. for 5 hours, and the core component was used. , Homopolyethylene terephthalate (intrinsic viscosity = 0.62, melting point = 26
(0 ° C.) The chips were vacuum dried at 160 ° C. for 5 hours. Both components are put into a composite spinning machine, the sheath component is melted by a melter at 250 ° C. to melt the chips, and the gear pump measures 8 g / min, and the core component is melted by a melter at 290 ° C. and the gear pump measures 32 g / min. And the hole diameter is 0.2
It was fed and spun into a core-sheath type composite spinneret having 3 mmφ and 66 holes.
The temperature of the flow path of the molten polymer and the die was 290 ° C. After the polymer discharged from the die is cooled and solidified, it is sucked with an air ejector with an air pressure of 0.5 kg / cm ² and collected on the net conveyor while opening the single yarn through the collision plate,
An unstretched nonwoven fabric sheet having a basis weight of 120 g / m ² was obtained by passing through a 70 ° C. hot roll. The fineness of the fibers ejected from the air ejector was 295 denier-66 filament (single yarn fineness 4.5d), breaking strength 1.0g / d, and elongation 326%.

On the other hand, polyethylene terephthalate copolymerized with 14 mol% of isophthalic acid (intrinsic viscosity = 0.68,
The melting point of 225 ° C.) chips were vacuum dried at 150 ° C. for 5 hours and put into an extruder having a screw diameter of 40 mm. T
It was extruded at a die die temperature of 280 ° C. and cast on a cooling drum having a diameter of 300 mm to produce an unstretched film. Next, the unstretched nonwoven fabric was placed on the unstretched film, supplied to a heating roll, and thermocompression bonded at a roll temperature of 80 ° C. The laminated sheet thus obtained was stretched 3.5 times in the length direction with a heating roll at 90 ° C., then fed into a tenter type stretching machine, stretched 4 times in the width direction at 95 ° C., and further 160 ° C. in a tenter. Heat treatment for 5 seconds, thickness 30μ
m heat-sensitive stencil printing base paper was prepared. On the film surface of the heat-sensitive stencil printing base paper, a wax-based mold release agent was applied in a gravure coater at a dry weight of 0.1 g / m ² at the inlet of the tenter. The fiber basis weight of the obtained heat-sensitive stencil printing base paper was 9.5 g / m ² , and the average fineness was 1.1.
It was denier. The thickness of the film alone is 2 μm
Met. This stretching process could be performed without any problems.

The obtained heat-sensitive stencil printing base paper was observed with an optical microscope. As a result, the contact portion between the film and the fiber and the entanglement point between the fibers formed a firmly fused network and A thin film fold was formed on the attachment.

The heat-sensitive stencil printing base paper was evaluated by printing.
The heat-sensitive stencil printing base paper also has good runnability, the printed matter has no unevenness in density, the characters are clear, and the thickness of ruled lines does not vary.
The black solid part had no white spots.

Comparative Example 1 In Example 1, homopolyethylene terephthalate (intrinsic viscosity = 0.62, melting point 2)
(60 ° C.) The chips were put into a single-component spinning machine, melted with a melter at 290 ° C., weighed with a gear pump at 40 g / min, and fed into a spinneret having a hole diameter of 0.23 mmφ and 66 holes for spinning. The spinning temperature of the molten polymer flow path and the spinneret is 290 ° C, and the polymer discharged from the spinneret is cooled and solidified, then sucked by an air ejector (air pressure 0.5 kg / cm ² ) and put on a net conveyor through a collision plate. The yarn was opened and collected, and passed through a hot roll of 80 ° C. to obtain an unstretched nonwoven fabric sheet having a basis weight of 120 g / m ² . The fineness of the fibers ejected from the air ejector was 305 denier-66 filament (single yarn fineness 4.6d), breaking strength 1.6g / d, and elongation 240%.

Then, in the same manner as in Example 1, the above-mentioned unstretched nonwoven fabric was placed on the unstretched film, and after thermocompression bonding, co-stretching was performed. However, the same draw ratio stretching as in Example 1 could not be performed, and the stretching was carried out 2.5 times in the length direction and 3 times in the width direction to prepare a heat-sensitive stencil printing base paper having a thickness of 45 μm.

The resulting heat-sensitive stencil printing base paper had a fiber areal weight of 17 g / m ² and an average fineness of 1.5 denier.
The thickness of the film alone was 2.5 μm.

Observation of this heat-sensitive stencil printing base paper with an optical microscope showed that the contact portion between the film and the fiber was firmly fused, but the entanglement points between the fibers were in a temporarily fixed state.
It was observed that the fibers were lifted from the film surface. Therefore, the thin film-like folds at the fused portion were not recognized.

The heat-sensitive stencil printing base paper was evaluated by printing.
Probably because the dimensional stability of the heat-sensitive stencil printing base paper was slightly inferior, the printed matter had uneven density, lacked sharpness, and had white spots in the black solid portions.

Comparative Example 2 In Example 1, homopolyethylene terephthalate (intrinsic viscosity = 0.62, melting point 2)
(60 ° C.) The chips were put into a single-component spinning machine, melted with a melter at 290 ° C., weighed with a gear pump at 40 g / min, and fed into a spinneret having a hole diameter of 0.23 mmφ and 66 holes for spinning. The spinning temperature of the molten polymer flow path and spinneret is 290 ℃, and the polymer discharged from the spinneret is cooled and solidified, then sucked with an air ejector (air pressure 4 kg / cm ² ) and the single yarn is put on the net conveyor through the collision plate. The fibers were collected by opening and passed through a hot roll at 130 ° C. to obtain a nonwoven sheet. This nonwoven fabric sheet had a basis weight of 8 g / m ² . The fineness of the fibers ejected from the air ejector is 75 denier-66 filament (single yarn fineness 1.1d), breaking strength 4.5g / d, elongation 6
It was 0%.

On the other hand, as in Example 1, isophthalic acid 14
Polyethylene terephthalate copolymerized by mol% was extruded from the T-die die onto the cast drum, and the length was 3.5.
The film was biaxially stretched twice and four times in the width direction to produce a polyester film having a thickness of 2 μm. Next, the fibrous nonwoven fabric and the polyester film were bonded together using a vinyl acetate resin. The amount of adhesive applied was 1 g / m ² . Next, a wax-based release agent was applied to the film surface to give a weight of 0.1 g / m ² after drying.
It was applied to prepare a heat-sensitive stencil printing base paper. This laminating process, the film and the non-woven fabric sheet were also thin, and sometimes wrinkled. This heat-sensitive stencil printing base paper was evaluated for printability. Permeability of the printing ink was hindered by the adhesive, and the clearness of the printing interface was lacking.

[0060]

INDUSTRIAL APPLICABILITY The heat-sensitive stencil printing base paper of the present invention does not use any adhesive to bond the polyester film and the porous support. Moreover, the porous support is configured without using a binder or the like. Therefore, since the adhesive does not impede the transmission of the printing ink at all, the printed matter obtained by stencil printing using the heat-sensitive stencil printing base paper of the present invention has high imageability and is excellent in printing sharpness. . Further, the fibers constituting the support are fused to each other at the entanglement point to form a net-like body, and since the thin film folds are formed at the fused portion, the support is excellent in strength, and Excellent balance between printing ink retention and transparency.

According to the manufacturing method of the present invention, since the adhesive coating step, the drying step, the solvent recovery step and their equipment are not required in the manufacturing process, the manufacturing cost can be greatly reduced. Further, since the film and the porous support are thermocompression-bonded and integrally co-stretched,
The support fiber exerts a reinforcing effect to prevent film breakage during stretching, resulting in a reduction in manufacturing cost.

Claims (7)

[Claims] 1. A heat-sensitive stencil printing base paper comprising a polyester film layer and a porous support layer made of a polyester fiber formed by forming a network in which fibers are fused to each other at their contact points, wherein A base paper for heat-sensitive stencil printing, characterized in that the polyester fiber forming the support layer has a core-sheath structure and has a fold in the fused portion. 2. The base paper for heat-sensitive stencil printing according to claim 1, wherein the porous support layer is made of polyester long-fiber nonwoven fabric. 3. The melting point of the sheath component of the polyester fiber is lower than that of the film layer, and 5 to 7 of the polyester fiber.
The heat-sensitive stencil printing base paper according to claim 1 or 2, wherein 0% by weight is a sheath component. 4. A polyester fiber having a single fiber fineness of 0.3 to
10 denier, the basis weight of the porous support is 2 to 20 g / m
^2. The heat-sensitive stencil printing base paper according to claim 1, 2, or 3. 5. A polyester film having a thickness of 0.1 to 10
The heat-sensitive stencil printing base paper according to claim 1, which is a biaxially stretched film having a thickness of μm. 6. A heat-sensitive material characterized in that an unstretched polyester film and a nonwoven fabric made of unstretched polyester fiber having a core-sheath structure having a melting point lower than that of the polyester film are thermocompression bonded and then biaxially stretched. Manufacturing method of stencil printing base paper. 7. The method for producing a base paper for heat-sensitive stencil printing according to claim 6, wherein the non-woven fabric comprises a polyester long-fiber non-woven fabric.