JPH10337974A - Thermosensible stencil printing base paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid occurrence of crease during a period of setting on plate by specifying a coefficient of static friction between a carrier surface and a metal plate into a specific value in a thermosensible stencil printing paper consisting of a polyester film and porous carrier. SOLUTION: At the time of measurement of a metal plate, a coefficient μS of the porous carrier surface of paper is made to be 0.3 or more and 1 or less. Preferably, it is made to be 0.35 or more and 0.9 or less and, more preferably, 0.4 or more and 0.8 or less. The coefficient of static friction μS is obtained from μS=Fs/Fd by making the degree of an initial shearing force into Fs when paper is cut out into 100 mm in length and 75 mm in width to thereby be in contact with regard to the metal plate having a surface roughness of 6.3S or more and 100S or less by its porous carrier surface, a weight (this is made into surface pressure Fp) is put on the film surface to subsequently be allowed to travel at 150 mm/min. Besides, the longitudinal orientation of paper mentioned herein is a longitudinal orientation (traveling orientation) of paper wound up in a roll shape, and the lateral orientation is a width orientation of paper.

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 sheet perforated by a thermal head or the like, and more particularly to a heat-sensitive stencil sheet which is free from wrinkles at the time of printing. Things.

[0002]

2. Description of the Related Art Conventionally, as heat-sensitive stencil base paper,
Polyester film, vinylidene chloride film, etc. thermoplastic resin film, natural fiber, synthetic fiber or synthetic fiber or a thin paper, nonwoven fabric, gauze, etc. made by mixing these are bonded with an adhesive. Structures are known (see, for example,
2513, JP-A-57-182495, etc.).

In recent years, heat-sensitive stencil printing machines have been improved to meet the demands for high-definition printing and high-speed plate making, such as increasing the density of thermal elements of a thermal head and reducing plate making energy. Highly sensitive base paper is required.

In order to improve the sensitivity, a film having a specified thickness (Japanese Patent Publication No. 3-65280) and a film having a biaxially stretched polyester film having specified thermal characteristics (Japanese Patent Application Laid-Open No. 62-282988). Japanese Patent Application Laid-Open No. Sho 62-149496), a film having a specified heat shrink characteristic (Japanese Patent Application Laid-Open No. 62-282983, Japanese Patent Application Laid-Open No. 63-160895), and the like. Although heat-sensitive stencil printing papers using these films have improved sensitivity, there is a problem that the paper is greatly curled during transportation or plate-making, although the base paper is greatly curled.

Japanese Patent Application Laid-Open No. Hei 6-305273 discloses that a base paper is obtained by co-drawing an undrawn polyester film and an undrawn polyester fiber. The base paper does not require the use of an adhesive and has high sensitivity, but it has been found that there is a problem that wrinkles are easily generated at the time of printing.

Further, a nonwoven fabric having a specified basis weight, thickness and flexural rigidity (Japanese Patent Laid-Open No. 3-76894) has been proposed in order to prevent wrinkles and wrinkles during lamination of a film and a nonwoven fabric. The base paper used as a support was still insufficient for preventing wrinkles during plate-making.

In heat-sensitive stencil printing, an image of an original is read by an optical sensor, sent as a digital signal to a thermal head, and the heat generated by the thermal head heats and melts the thermoplastic resin film of the base paper to form a perforated plate. After the master is wound around a drum and a printing sheet is supplied, the printing paper is supplied with pressure, and the printing ink is leached from the porous support side into the perforated portion to perform printing.

The above-mentioned conventional base paper has a disadvantage that wrinkles are easily generated when the master is wound around a drum. When observing the appearance of wrinkles, the master made is clamped at the leading end and wound around the drum as the drum rotates, but when the rear end of the master is cut by a cutter, the drum is placed in a tension-free state. Wrapped around. At this time, the master is landed on the drum in a state where the master bites air. Next, with the rotation of the drum, the master is pressed by the press roll via the printing paper. The press rolls crush the air-engaged portion, causing wrinkles in the master.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems in the conventional base paper and to provide a base paper free from wrinkling during plate formation.

[0010]

Means for Solving the Problems In view of the above-mentioned problems, the present inventors have made intensive studies and as a result, have set the coefficient of static friction between the surface of the porous support of the base paper and the surface of the metal plate to a specific range. The inventors have found that the problem is solved, and have reached the present invention.

That is, the present invention relates to a heat-sensitive stencil sheet comprising a polyester film and a porous support, wherein the coefficient of static friction μs between the surface of the porous support and the metal plate is 0.3 or more and less than 1.0. A heat-sensitive stencil printing base paper characterized in that:

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, when measured on a metal plate, the coefficient of static friction μ
s needs to be 0.3 or more and less than 1. Preferably it is 0.35 or more and less than 0.9, more preferably 0.4 or more and less than 0.8. If the coefficient of static friction μs is less than 0.3, wrinkles are likely to be generated at the time of printing, which is not preferable. On the other hand, if the coefficient of static friction μs is 1 or more, the ink permeability of the support and the image quality of the printed matter deteriorate, which is not preferable.

Here, the static friction coefficient μs means that a base paper is cut into a length of 100 mm and a width of 75 mm, and the surface roughness of a metal sheet having a surface roughness of 6.3S or more and 100S or less is measured using a slip tester manufactured by Toray Engineering Co., Ltd. Assuming that the magnitude of the initial elastic force when the film is run at 150 mm / min is Fs, a load of 200 g is applied to the film surface (this is referred to as a surface pressure Fp).
It is obtained from the following equation. μs = Fs / Fp In the present invention, the longitudinal direction of the base paper refers to the longitudinal direction (running direction) of the base paper wound in a roll shape, and the horizontal direction refers to the width direction of the base paper.

Further, in the present invention, the maximum bending torque in either the longitudinal direction or the lateral direction of the base paper is 0.5 N · when measured with a KES type pure bending tester at a clamp interval of 1 cm.
It is preferably at least cm / cm. More preferably 1.0 N · cm / cm or more, and still more preferably 1.4 N
-It is cm / cm or more. When the maximum bending torque in either the vertical or horizontal direction is 0.5 N · cm / cm or more,
Wrinkles are less likely to occur at the time of printing. On the other hand, if the maximum bending torque is less than about 4.0 N · cm / cm, the perforation sensitivity of the film and the ink permeability of the support become good.

The maximum bending torque referred to in the present invention is KES
Type pure bending tester (Kato-Tech Corporation KES-FB2)
Using a sample length 20 cm, clamp width 1 cm, in a range of curvature -2.5cm ^-1 ~ + 2.5cm ^-1, performs pure bending test of constant velocity curvature deformation rate 0.5 cm ^-1 / s , Means the maximum value of the bending moment in the obtained bending moment-curvature diagram.

The base paper of the present invention preferably has a KES type bending stiffness B value of 0.1 to 2.0 N · cm ² / cm.
It is more preferably 0.2 to 2.0 N · cm ² / cm, particularly preferably 0.4 to 3.0 N · cm ² / cm or more. KES type flexural rigidity B value is 0.1 to 2.0 N · cm ²
/ Cm, traveling in the printing press is good.

The thickness of the polyester film of the present invention is preferably 0.1 to 5 μm, more preferably 0.5 to 3 μm.
μm, particularly preferably 0.5 to 2.5 μm. If the thickness is 5 μm or less, the piercing property does not decrease,
When the thickness is 0.1 μm or more, the film formation stability is good.

In the polyester film of the present invention, the orientation parameter is preferably from 3 to 10, more preferably from 3.5 to 8, particularly preferably from 4 to 7. When the orientation parameter is 3 to 10, the film can be sufficiently contracted by heat perforation of the thermal head, and a base paper having high perforation sensitivity can be obtained.

The orientation parameter in the present invention was determined by laser Raman spectroscopy. The film is embedded in PMMA resin and wet polished to form a cross section perpendicular to the length or width direction of the film, for example, Jobin Yvo.
n / “Ramanor” U-1000 manufactured by Atago Bussan Co., Ltd.
I (light source: GLG3300 Ar ⁺ laser 514.5 nm, manufactured by NEC Corporation, microscope: BH-2 type objective lens × 100 manufactured by Olympus Optical Industries, Ltd.)
A laser beam is irradiated perpendicularly to the cross section, and the Raman spectrum 1615 of the laser beam polarized in the plane direction of the film and the laser beam polarized in the thickness direction of the film is irradiated.
When the peak intensities of the cm ^-1 band were defined as I and I _ND , respectively, the ratio I / _IND was used as the orientation parameter of the film.

The melting point of the polyester film of the present invention is 2
The temperature is preferably 30 ° C or lower, more preferably 220 ° C or lower. When two or more peaks of the melting point exist when measured with a differential scanning calorimeter, it is preferable that at least one peak temperature is 230 ° C. or lower. Melting point 2
When the temperature is 30 ° C. or lower, the heat perforation property of the film becomes good.

The melting point of the polyester film of the present invention is preferably lower than the melting point of the porous support, particularly preferably the difference is 5 ° C. or more, more preferably 10 ° C. or more. When the melting point of the film is lower than the melting point of the support, the support is preferably not thermally deformed by the heat of the thermal head during plate making.

The polyester film of the present invention preferably has a crystal melting energy (ΔHu) of 10 to 50 J.
/ G, more preferably 15 to 40 J / g. ΔHu
Is 10 to 50 J / g, the perforated shape of the film becomes uniform and stable.

The basis weight of the porous support of the present invention is preferably ² to ²⁰ g / m ² , more preferably 2 to 16 g / m 2.
g / m ^2, particularly preferably 3~14g / m ^2. When the basis weight is ² to 20 g / m ² , the balance between the ink holding property and the permeability is excellent.

The fiber diameter of the polyester fiber constituting the porous support of the present invention is preferably 0.5 to 20 μm, more preferably 1 to 15 μm, and particularly preferably 2 to 12 μm.
It is. When the fiber diameter is 0.5 μm or more, sufficient strength as a support is obtained, and when the fiber diameter is 20 μm or less, the flatness of the film is good.

When the porous support of the present invention is a polyester fiber, its crystallinity is preferably at least 10%, more preferably at least 15%, particularly preferably at least 20%.
That is all. When the crystallinity is 10% or more, sufficient heat resistance as a support can be obtained.

The thickness of the base paper of the present invention is preferably from 30 to 120 μm, more preferably from 30 to 120 μm.
00 μm, particularly preferably 30 to 80 μm. When the thickness of the entire base paper is 30 μm or more, the ink is not faded even when a large number of sheets are printed, and when the thickness is 120 μm or less, no set-off occurs.

The polyester in the present invention is not particularly limited as long as it has a heat-perforating property, but is mainly composed of an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid or an alicyclic dicarboxylic acid and a diol. Here, as the aromatic dicarboxylic acid component, for example, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6
-Naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, etc., among which terephthalic acid, isophthalic acid, 6-naphthalenedicarboxylic acid or the like can be used. Examples of the aliphatic dicarboxylic acid component include succinic acid, adipic acid, suberic acid, sebacic acid,
Dodecanedioic acid, eicosandioic acid, dimer acid and the like can be used. As the alicyclic dicarboxylic acid component, for example, 1,4-cyclohexanedicarboxylic acid or the like can be used. One of these acid components may be used alone, or two or more thereof may be used in combination. Further, an oxyacid such as hydroxybenzoic acid may be partially copolymerized.
As the diol component, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis (4-hydroxy Ethoxyphenyl) propane and the like can be used. Among them, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and 1,4-cyclohexanedimethanol are preferably used. These diol components may be used alone or in combination of two or more.

The polyester used in the polyester film of the present invention is preferably polyethylene terephthalate, a copolymer of ethylene terephthalate and ethylene isophthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polyhexamethylene. -2,6-naphthalate, copolymer of butylene terephthalate and ethylene terephthalate, copolymer of butylene terephthalate and hexamethylene terephthalate, copolymer of hexamethylene terephthalate and 1,4-cyclohexane dimethylene terephthalate, ethylene terephthalate And a blend of ethylene-2,6-naphthalate and a blend thereof. Particularly preferred for improving the perforation sensitivity, a copolymer of ethylene terephthalate and ethylene isophthalate, polyhexamethylene terephthalate, hexamethylene terephthalate and 1,4-cyclohexane dimethylene terephthalate,
A copolymer of ethylene terephthalate and ethylene-2,6-naphthalate can be used.

The ink-permeable porous support of the present invention refers to a nonwoven fabric which allows the passage of printing ink and does not substantially undergo thermal deformation under heating conditions under which a film is perforated.
Woven fabric or other porous bodies can be used. The porous support is preferably a nonwoven fabric, and a polyester nonwoven fabric made of polyester fibers is particularly preferred.

In the present invention, the polyester constituting the nonwoven fabric has, as in the case of the polyester film, an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid or an alicyclic dicarboxylic acid and a diol as main components. Preferably, polyethylene terephthalate, polyethylene-2,6-naphthalate, poly-1,4-cyclohexane dimethylene terephthalate, a copolymer of ethylene terephthalate and ethylene isophthalate, and the like can be used. Particularly preferred is polyethylene terephthalate, polyethylene-
2,6-naphthalate.

The polyester fiber preferably used in the present invention may contain, if necessary, an organic lubricant such as a flame retardant, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a pigment, a dye, a fatty acid ester, or a wax. An antifoaming agent such as siloxane can be blended. Also, if necessary, to impart an affinity to the ink, an acid,
Chemical treatment such as alkali treatment, corona treatment, low-temperature plasma treatment, or the like may be performed.

Next, the method for producing the heat-sensitive stencil sheet of the present invention will be described.

The polyester preferably used in the present invention can be produced by the following 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 remove the excess diol component and polycondensate to produce a dialkyl acid. There is a method of using an ester, performing a transesterification reaction between the ester and a diol component, and then performing polycondensation in the same manner as described above. At this time, if necessary, a metal compound can be used as a reaction catalyst, and a phosphorus compound or the like can be used as a heat stabilizer.

The unstretched polyester film preferably used in the present invention can be prepared by extruding a polymer onto a cooling drum by, for example, a T-die extrusion method using the above polyester. An unstretched film having a desired thickness can be produced by adjusting the slit width of the die, the discharge amount of the polymer, and the rotation speed of the cast drum. At this time, a so-called electrostatic application casting method in which static electricity is applied to the polymer to increase the adhesion to the drum can also be used.

The polyester film of the present invention may optionally contain a flame retardant, an antioxidant, an ultraviolet absorber, a pigment, a dye, an antifoaming agent such as polysiloxane, and the like. Further, the following lubricity imparting method can be adopted. For example, a method of blending inorganic particles such as clay, mica, titanium oxide, calcium carbonate, kaolin, talc, wet or dry silica, alumina, zirconia, organic particles containing acrylic acid, styrene, etc., a polyester polymerization reaction There is a method using so-called internal particles in which a catalyst or the like to be added sometimes is precipitated.

The intrinsic viscosity of the polyester used for the film is preferably 0.5 or more, more preferably 0.6 or more, and particularly preferably 0.65 or more. When the intrinsic viscosity is 0.5 or more, the film-forming stability is good, and particularly, casting of a thin film becomes easy.

The heat-sensitive stencil printing paper of the present invention is prepared by a method of bonding a polyester film and a porous support with an adhesive under conditions that do not hinder the perforation characteristics of the film or a method of bonding without an adhesive. However, from the viewpoint of print quality, it is more preferable that they are joined without using an adhesive.

The method for adhering the polyester film and the porous support without using an adhesive is not particularly limited, but when the porous support is a polyester fiber, an unstretched polyester film and an unstretched polyester are used. This is preferably achieved by thermally bonding a porous support made of fibers and simultaneously co-stretching both.

In order to thermally bond the unstretched polyester film and the support made of unstretched polyester fiber, usually, the unstretched polyester film and the support made of unstretched polyester fiber are heated in a state of being overlapped. It is preferable to perform the pressurization while applying pressure, and the method is not particularly limited, but heat bonding using a heating roll is particularly preferable. The heat bonding temperature is preferably around the glass transition point (Tg) of the polyester film, and particularly preferably in the range of Tg-10 ° C to Tg + 30 ° C. The pressure at the time of thermal bonding is 0.1 to 1 in roll linear pressure.
It is preferably performed in the range of 00 N / cm.

The method of co-stretching the heat-bonded unstretched polyester film and the unstretched polyester fiber is not particularly limited, and may be either uniaxial stretching or biaxial stretching. More preferred. The biaxial stretching may be either a sequential biaxial stretching method or a simultaneous biaxial stretching method, but the sequential biaxial stretching is particularly preferred. In the case of sequential biaxial stretching, it is general that transverse stretching is generally performed by a tenter after longitudinal stretching by a group of heating rolls, but may be reversed. As the material of the heating roll, metal, "Teflon", ceramic, silicone rubber and the like are preferably used. The material of the nip roll is particularly preferably silicone rubber. The nip pressure during stretching is 0.1 to
It is preferable to carry out in the range of 100 N / cm. The stretching temperature is preferably between 50 ° C and 150 ° C, more preferably 60 ° C.
It is preferable to carry out at a temperature in the range of from 130C to 130C. Further, in order to uniformly perform heating during stretching, only the polyester fiber of the support may be preheated alone and then supplied to the stretching roll.
Further, in order to uniformly stretch the polyester film and the polyester fiber of the support, the heat-bonded film and the support may be heated by an infrared heater or the like immediately before stretching.

The stretching ratio is not particularly limited, but is usually preferably 2 to 8 times each in the vertical and horizontal directions, more preferably 3 to 8 times.
Double is appropriate. After biaxial stretching, the film may be stretched longitudinally or horizontally, or vertically and horizontally again.

The porous support composed of unstretched polyester fibers preferably used in the present invention can be produced in the form of a nonwoven fabric by a direct melt spinning method such as a melt blow method or a spun bond method.

For example, in the melt blow spinning method, when a molten polymer is discharged from a die, hot air is blown from the periphery of the die, the discharged polymer is made finer, and then the net conveyor is arranged at an appropriate position. It is collected by spraying on the top and manufactured as a non-woven web. Since the web is sucked together with the hot air by the suction device provided on the net conveyor, the fibers are collected before the fibers are completely solidified. That is, the fibers are collected in a state where they are fused to each other. By appropriately setting the collection distance between the base and the net conveyor, the degree of fusion between the fibers can be adjusted. Also, by appropriately adjusting the amount of discharged polymer, the temperature of hot air, the flow rate of hot air, the conveyor speed, and the like, the thickness and basis weight of the fibers can be adjusted. The melt-blow spun fiber is made finer by the pressure of hot air and solidified in a non-oriented or extremely low-oriented so-called undrawn state. The polymer discharged from the die is rapidly cooled from a molten state to an atmosphere at room temperature, so that it solidifies in a low-crystalline state close to amorphous.

Similarly, in the spun bond method, the polymer discharged from the die is pulled by an air ejector, and the obtained filaments are caused to collide with a collision plate to spread the fibers.
It is manufactured by collecting it on a conveyor. The weight of the nonwoven fabric can be arbitrarily set by appropriately setting the polymer discharge amount and the conveyor speed. By appropriately adjusting the pressure and flow rate of the ejector, the thickness of the fiber and the molecular orientation can be adjusted. By reducing the spinning speed by reducing the pressure and the flow rate, a nonwoven fabric having a low degree of molecular orientation and close to an undrawn state can be obtained. Further, by adjusting the cooling rate of the discharged polymer, a non-woven fabric having low crystallinity can be obtained.

In the case of production by the spunbond method, the unstretched polyester nonwoven fabric used for obtaining the base paper of the present invention is preferably spun at a spinning speed of 1500 m / min or less, more preferably 1000 m / min or less, particularly preferably 1000 m / min or less. Preferably it is 800 m / min or less.

The crystallinity of the unstretched polyester nonwoven fabric preferably used in the present invention is preferably 20% or less, more preferably 10% or less, and particularly preferably 5% or less.

The unstretched polyester nonwoven fabric preferably used in the present invention is most preferably unstretched. However, even if it is stretched, it preferably has a low magnification and a low degree of orientation, and is referred to as birefringence (Δn). , 0.03 or less, more preferably 0.02 or less, particularly preferably 0.01 or less. Here, birefringence refers to the use of a sodium lamp as a light source and
-It is a value calculated by obtaining retardation by the Berk convention method under immersion in promnaphthalene.

The intrinsic viscosity of the polymer used for the polyester nonwoven fabric is preferably 0.35 or more, more preferably 0.4 or more, and particularly preferably 0.45 or more. If the intrinsic viscosity is 0.35 or more, a fiber having sufficient strength can be obtained.

Thereafter, the base paper of the present invention after biaxial stretching may be subjected to a heat treatment. The heat treatment temperature is not particularly limited and is determined depending on the type of the polymer for a film to be used, but is preferably from 80 to 200 ° C, more preferably from 80 to 170 ° C, further more preferably from 90 to 150 ° C, and the time is from 0.1 to 150 ° C. About 5 to 60 seconds is appropriate.

Further, the base paper obtained by the heat treatment may be once cooled to about room temperature and then aged at a relatively low temperature of 40 to 90 ° C. for about 5 minutes to 1 week.
The use of such aging is particularly preferable because curling during storage of the base paper or in the printing press can be suppressed.

The method for setting the static friction coefficient μs between the metal plate and the surface of the porous support of the base paper within the range of the present invention is not limited. However, particularly when the porous support is a polyester nonwoven fabric, the unstretched nonwoven fabric used is It can be achieved by appropriately adjusting the fiber diameter, the state of adhesion between fibers, the stretching temperature during stretching, and the like. The heat-sensitive stencil sheet of the present invention has a large static friction coefficient μs as compared with the conventional base paper, so that the base paper is easily peeled off from the plate cylinder with the ink, and the air between the base paper and the plate cylinder is easily released. The generation of wrinkles at the time can be suppressed. In general, the rougher the surface of the porous support, the larger the coefficient of static friction μs against the metal plate tends to be. That is, the larger the fiber diameter and the weaker the adhesion between the fibers, the larger the static friction coefficient μs. As a method for increasing the fiber diameter, a method of adjusting the speed of hot air in the spinning step of the undrawn nonwoven fabric is used. The method of weakening the adhesion between the fibers can be achieved by adjusting the temperature of the hot air or the ambient temperature to lower the temperature of the fiber collecting surface, or reducing the suction pressure of the suction. From the viewpoint of making only the outer layer of the nonwoven fabric surface have a desired surface roughness, a method of laminating unstretched nonwoven fabrics having different fiber diameters and co-stretching with an unstretched film is also preferably performed. Alternatively, it is preferable to roughen the nonwoven fabric surface of the base paper obtained by co-stretching by a raising treatment, an embossing treatment, a low-temperature plasma treatment or the like.

The base paper of the present invention is used to prevent fusing at the time of perforation on one side of the film to be in contact with the thermal head.
Silicone oil, silicone resin, fluorine resin,
It is preferable to provide a thin layer comprising a surfactant, an antistatic agent, a heat-resistant agent, an antioxidant, organic particles, inorganic particles, a pigment, a dispersing agent, a preservative, an antifoaming agent, and the like. The thickness of the thin layer for preventing fusion is preferably 0.005 μm or more and 0.4 μm or less,
More preferably, it is 0.01 μm or more and 0.4 μm or less.

When a thin layer for preventing fusion is provided on the base paper of the present invention, a method of applying a coating solution in the form of a coating solution dissolved, emulsified or suspended in water, and then removing the water by drying or the like is used. preferable. The coating may be performed at any stage before or after the stretching of the film. In order to make the effect of the present invention more remarkable, it is particularly preferable to apply before horizontal stretching in the case of sequential biaxial stretching such as horizontal stretching after longitudinal stretching, and before stretching in the case of simultaneous biaxial stretching. . The application method is not particularly limited, but application is preferably performed using a roll coater, a gravure coater, a reverse coater, a bar coater, or the like.

Before the thin layer for preventing fusion is provided, if necessary, an activation treatment such as a corona discharge treatment may be applied to the coated surface in air or other various atmospheres.

[0055]

[Method of measuring characteristics]

(1) Static friction coefficient μs The static friction coefficient μs between a metal plate (having a surface roughness of 6.3S or more and 100S or less) and the surface of the porous support of the base paper was determined according to ASTM-D18.
The measurement was performed using a slip tester manufactured by Toray Engineering Co., Ltd. in accordance with No. 94. The measurement was performed under the conditions of a room temperature of 23 ° C. and a relative humidity of 50%.

The static friction coefficient μs can be obtained from the following equation, where the load applied to the film surface is the surface pressure Fp, and the maximum load when running at 150 mm / min is Fs.

Μs = Fs / Fp

(2) Maximum bending torque (N · cm / cm) KES-type pure bending tester (KES-
Using FB2), a sample having a length of 20 cm was gripped with a clamp width of 1.0 cm, and the curvature K was from −2.5 cm ⁻¹ to +2.
A pure bending test was performed at a constant velocity curvature at a deformation rate of 0.5 cm ^-1 / s in a range of 5 cm ^-1 , and the obtained bending moment (unit: N · cm) and curvature (unit: cm ^-1 ) lines were obtained. In the figure, the maximum value of the bending moment was obtained as the maximum bending torque.

The measurement was carried out at five points in each of the longitudinal direction and the lateral direction of the base paper, and the average value was represented.

(3) Melting point (° C.) Differential scanning calorimeter RDC220 manufactured by Seiko Electronic Industry Co., Ltd.
Using a mold, a 5 mg sample was collected, and the temperature was
It was determined from the peak temperature of the endothermic curve when the temperature was raised at a rate of ° C./min.

(4) Film Thickness (μm) A section of the base paper was cut out, and the section was observed by a scanning electron microscope at a magnification of 1,000 to 10,000 times.

(5) Overall thickness of base paper (μm) A dial thickness gauge (“PEACOC” manufactured by Ozaki Seisakusho Co., Ltd.)
K ″ H type).

(6) Crystal melting energy (ΔHu) Differential scanning calorimeter RDC220 manufactured by Seiko Electronic Industry Co., Ltd.
It is determined from the area at the time of melting using a mold. This area is shifted from the baseline to the absorption side by increasing the temperature, and is the area until the temperature returns to the baseline position when the temperature is further increased.The area from the melting start temperature position to the end position is connected by a straight line. (A) is obtained. I under the same DSC conditions
n (indium) was measured, and this area (b) was determined to be 28.5.
It is calculated by the following equation as J / g.

28.5 × a / b = ΔHu (J / g)

(7) Support weight (g / m ² ) A piece of base paper 20 cm × 20 cm was taken and its weight was measured. The weight of the film was reduced and converted to the weight per m ² . The weight of the film was determined by multiplying the film thickness by the density.

(8) Evaluation of wrinkles The prepared base paper was supplied to a printing machine “RISOGRAPH” (GR275) manufactured by Riso Kagaku Kogyo Co., Ltd., and plate making / printing tests were performed 100 times using all B4 size solid originals. Then, the base paper of the plate cylinder was visually observed and judged as follows.

原: no wrinkles were generated on the base paper; し た: one or two wrinkles;: three to five wrinkles; ×: six or more wrinkles. ◎, △, Δ are practically usable.

(9) Evaluation of Ink Permeability The prepared base paper was supplied to a printing machine “Risograph” (GR275) manufactured by Riso Kagaku Kogyo Co., Ltd.
The base paper of the plate cylinder after 2 seconds was visually observed and judged as follows.

A case where there is no omission and the ink has spread over the entire surface is ◎ A slightly small unevenness is seen, but a case where the ink is almost completely applied is ○ The unevenness is seen at some places, but the ink is Those that were familiar were marked with △, and those with significant unevenness of the ink, and where there was a part where the ink was not familiar at all, were evaluated as x. ◎, △, Δ are practically usable.

[0070]

The present invention will be described in more detail with reference to the following examples.

Example 1 A polyethylene terephthalate raw material ([η] = 0.50,
Tm = 255 ° C.), pore diameter 0.3 mm, number of holes 100
The polymer discharge amount is 35 g / min, the die temperature is 290 ° C., the hot air temperature is 295 ° C., the hot air flow rate is 400 N · m ³ / h, the collecting surface temperature is 100 ° C., the fiber diameter is 8.3 μm, and the melt weight is measured by melt blow method. An unstretched nonwoven fabric of 120 g / m ² was produced.

Then, a copolymerized polyester resin raw material ([η] = 0.70, Tm = 21) composed of 85 mol% of ethylene terephthalate and 15 mol% of ethylene isophthalate was used.
7 ° C.) using an extruder having a screw diameter of 90 mm,
It was extruded at a die temperature of 270 ° C. and cast on a cooling drum having a diameter of 500 mm to produce an unstretched film having a thickness of 20 μm.

The unstretched nonwoven fabric is superimposed on the unstretched film, supplied to a longitudinal stretching machine, passed through a group of preheating rolls, and adhered to the unstretched film. It was stretched 5 times and cooled to room temperature. At this time, the temperature of the film surface was measured between the stretching rolls using a non-contact thermometer, and the temperatures of the preheating roll and the stretching roll were adjusted so that the film surface temperature became 95 ° C. The nip linear pressure of the stretching roll was 5 N / cm.

Then, it is sent to a tenter type horizontal stretching machine,
The film was stretched 3.8 times in the width direction at a preheating temperature of 90 ° C. and a stretching temperature of 95 ° C., heat-treated at a temperature of 150 ° C. in a heat treatment zone in a tenter, and wound into a roll.

Next, a wax-based release agent was applied to the film surface to prepare a heat-sensitive stencil sheet. The thickness of the obtained base paper was 76 μm, the fiber diameter of the support was 4.3 μm, the basis weight was 10.5 g / m ² , and the thickness of the film was 1.5 μm.

The coefficient of static friction μs of the base paper against the metal plate on the side of the support was 0.39, and the maximum bending torque by a KES type pure bending tester was 0.95 / 0.97 N · cm / h.
cm.

Example 2 Example 1 was repeated except that the flow rate of hot air was changed to 350 N · m ³ / h to produce an unstretched nonwoven fabric having a fiber diameter of 10.5 μm and a basis weight of 120 g / m ^2. In the same manner as in the above, a heat-sensitive stencil sheet was prepared. The thickness of the obtained base paper is 80 μm, the fiber diameter of the support is 6.5 μm, and the basis weight is 1
0.5 g / m ² , and the thickness of the film was 1.5 μm.

The static friction coefficient μs of the base paper against the metal plate on the side of the support was 0.46, and the maximum bending torque by the KES type pure bending tester was 1.01 / 1.03 N · cm / h.
cm.

Example 3 Example 1 was repeated except that the flow rate of the hot air was changed to 300 N · m ³ / h, and an unstretched nonwoven fabric having a fiber diameter of 14.3 μm and a basis weight of 120 g / m ² was prepared. In the same manner as in the above, a heat-sensitive stencil sheet was prepared. The thickness of the obtained base paper is 85 μm, the fiber diameter of the support is 8.6 μm, and the basis weight is 1
0.5 g / m ² , and the thickness of the film was 1.5 μm.

The static friction coefficient μs of the base paper against the metal plate on the side of the support was 0.53, and the maximum bending torque by the KES type pure bending tester was 1.10 / 1.12 N · cm / longitudinal / horizontal.
cm.

Comparative Example 1 The procedure of Example 1 was repeated except that the flow rate of hot air was changed to 500 N · m ³ / h to produce an unstretched nonwoven fabric having a fiber diameter of 4.5 μm and a basis weight of 120 g / m ^2. A heat-sensitive stencil sheet was prepared in the same manner. The thickness of the obtained base paper is 7
0 μm, fiber diameter of support 2.1 μm, basis weight 10.5
g / m ² and the thickness of the film was 1.5 μm.

The static friction coefficient μs of the base paper against the metal plate on the side of the support was 0.20, and the maximum bending torque by the KES type pure bending tester was 0.54 / 0.58 N · cm / h.
cm.

Comparative Example 2 Example 1 was the same as Example 1 except that the flow rate of hot air was changed to 200 N · m ³ / h to produce an unstretched nonwoven fabric having a fiber diameter of 20.1 μm and a basis weight of 120 g / m ^2. A heat-sensitive stencil sheet was prepared in the same manner. The thickness of the obtained base paper is 90 μm, the fiber diameter of the support is 13.5 μm, and the basis weight is 1
0.5 g / m ² , and the thickness of the film was 1.5 μm.

The static friction coefficient μs of the base paper against the metal plate on the side of the support was 1.15, and the maximum bending torque by the KES type pure bending tester was 2.01 / 2.04 N · cm / h.
cm.

Example 4 The procedure of Example 1 was repeated, except that the collecting surface temperature was changed to 80 ° C., and an unstretched nonwoven fabric having a fiber diameter of 8.3 μm and a basis weight of 120 g / m ² was produced. Thus, a heat-sensitive stencil sheet was prepared. The thickness of the obtained base paper was 86 μm, the fiber diameter of the support was 4.3 μm, the basis weight was 10.5 g / m ² ,
The thickness of the film was 1.5 μm. The coefficient of static friction μs of the base paper against the metal plate on the side of the support was 0.49, KE
The maximum bending torque by the S-type pure bending tester is vertical / horizontal = 0.
64 / 0.70 N · cm / cm.

Example 5 The procedure of Example 1 was repeated, except that the collecting surface temperature was changed to 90 ° C., and an unstretched nonwoven fabric having a fiber diameter of 8.3 μm and a basis weight of 120 g / m ² was produced. Thus, a heat-sensitive stencil sheet was prepared. The thickness of the obtained base paper was 82 μm, the fiber diameter of the support was 4.3 μm, the basis weight was 10.5 g / m ² ,
The thickness of the film was 1.5 μm. The coefficient of static friction μs of the base paper against the metal plate on the support surface side is 0.46, KE
The maximum bending torque by the S-type pure bending tester is vertical / horizontal = 0.
86 / 0.88 N · cm / cm.

Comparative Example 3 In Example 1, the temperature of the collecting surface was changed to 120 ° C.
A heat-sensitive stencil sheet was prepared in the same manner as in Example 1 except that an unstretched nonwoven fabric having a fiber diameter of 8.3 μm and a basis weight of 120 g / m ² was prepared. The thickness of the obtained base paper is 69 μm,
The fiber diameter of the support is 4.3 μm, and the basis weight is 10.5 g /
m ² , and the thickness of the film was 1.5 μm.

The coefficient of static friction μs of the base paper against the metal plate on the support surface side is 0.21, and the maximum bending torque by the KES type pure bending tester is 1.57 / 1.49 N · cm / width.
cm.

[0089] In Example 6 Example 1, by changing the hot air flow and the conveyor speed, fiber diameter 10.5 [mu] m, the unstretched nonwoven 1 having a basis weight of 60 g / m ^2, fiber diameter 4.5 [mu] m, basis weight 60 g / m ² Was prepared in the same manner as in Example 1 except that the nonwoven fabric 2 was overlapped between the unstretched film and the nonwoven fabric 1 in the same manner as in Example 1. The thickness of the obtained base paper is 100 μm, the fiber diameter of the outer support 1 is 6.5 μm,
The basis weight was 5.0 g / m ² , the fiber diameter of the support ^{2 on} the film side was 2.1 μm, the basis weight was 5.0 g / m ² , and the thickness of the film was 1.5 μm.

The coefficient of static friction μs of the base paper against the metal plate on the side of the support was 0.42, and the maximum bending torque by the KES type pure bending tester was 0.98 / 0.96 N · cm / h.
cm.

Example 7 In Example 6, the nonwoven fabric 1 was changed in the conveyor speed to a fiber diameter of 10.5 μm and a basis weight of 40 g / m ² , and the nonwoven fabric 2 was changed in the conveyor speed to a fiber diameter of 4.5 μm and a basis weight. A heat-sensitive stencil sheet was prepared in the same manner as in Example 6 except that the amount was 80 g / m ² . The thickness of the obtained base paper is 1
00 μm, outer support 1 fiber diameter 6.5 μm, basis weight 2.5 g / m ² , film side support 2 fiber diameter 2.1 μm, basis weight 8.5 g / m ² , film thickness The height was 1.5 μm.

The static friction coefficient μs of the base paper against the metal plate on the side of the support was 0.40, and the maximum bending torque by the KES type pure bending tester was 0.72 / 0.74 N · cm / longitudinal / horizontal.
cm.

Comparative Example 4 The procedure of Example 7 was repeated except that the unstretched nonwoven fabric 1 was overlapped between the unstretched film and the unstretched nonwoven fabric 2.
In the same manner as in the above, a heat-sensitive stencil sheet was prepared. The thickness of the obtained base paper is 100 μm, the fiber diameter of the outer support 1 is 2.1 μm, the basis weight is 8.5 g / m ² , the fiber diameter of the support ^{2 on} the film side is 6.5 μm, and the basis weight is 2. 5 g / m ² , and the thickness of the film was 1.5 μm.

The coefficient of static friction μs of the base paper against the metal plate on the side of the support was 0.21, and the maximum bending torque by the KES type pure bending tester was 0.80 / 0.79 N · cm / longitudinal / horizontal.
cm.

Example 8 The same procedure as in Example 1 was carried out except that an unstretched nonwoven fabric having a fiber diameter of 8.3 μm and a basis weight of 75 g / m ² was prepared by changing the conveyor speed. Base paper was made. The thickness of the obtained base paper was 50 μm, the fiber diameter of the support was 4.3 μm, the basis weight was 6.2 g / m ² , and the thickness of the film was 1.5 μm.

The static friction coefficient μs of the base paper against the metal plate on the side of the support was 0.36, and the maximum bending torque by the KES type pure bending tester was 0.40 / 0.44 N · cm / longitudinal / horizontal.
cm.

Comparative Example 5 A heat-sensitive material was prepared in the same manner as in Example 1 except that the hot air flow rate and the conveyor speed were changed to produce an unstretched nonwoven fabric having a fiber diameter of 4.5 μm and a basis weight of 75 g / m ^2. A stencil sheet was prepared. The thickness of the obtained base paper is 55μ.
m, the fiber diameter of the support is 2.1 μm, and the basis weight is 6.2 g / m.
^2. The thickness of the film was 1.5 μm. The coefficient of static friction μs of the base paper against the metal plate on the support surface side is 0.18;
Maximum bending torque by KES type pure bending tester is vertical / horizontal =
It was 0.33 / 0.32 N · cm / cm.

Example 9 The base paper obtained in Example 1 was embossed using a metal engraving roll and a silicone rubber roll. The surface temperature of the metal roll was 70 ° C., and the linear pressure of the roll was 3 N / cm. An embossing process was performed so that the engraving roll was in contact with the support surface and the silicone rubber was in contact with the film surface. The thickness of the obtained base paper was 85 μm, the fiber diameter of the support was 4.3 μm, the basis weight was 11.5 g / m ² , and the thickness of the film was 1.5 μm.

The coefficient of static friction μs of the base paper against the metal plate on the side of the support was 0.47, and the maximum bending torque by the KES type pure bending tester was 0.71 / 0.73 N · cm / h.
cm.

[0100]

[Table 1]

[Table 2] As can be seen from the results in Tables 1 and 2, the base paper for heat-sensitive stencil printing of the present invention, in which the coefficient of static friction μs of the base paper against the metal plate on the nonwoven fabric side is 0.3 or more and less than 1.0, generates plate wrinkles. And the ink has good permeability and excellent print quality.

[0101]

The heat-sensitive stencil sheet of the present invention has a coefficient of static friction μs of 0.3 or more against the metal plate on the nonwoven fabric side.
Since it is configured to be less than 0, no wrinkles are generated when the prepressed stencil is applied on the plate cylinder. Therefore, a printed matter having high printing quality can be obtained by printing on the base paper of the present invention.

Claims (7)

[Claims] In a heat-sensitive stencil printing paper comprising a polyester film and a porous support, the coefficient of static friction μs between the outer surface of the porous support and the metal plate is 0.3 or more.
Base paper for heat-sensitive stencil printing, characterized by being less than 0. 2. The maximum bending torque of a base paper in a vertical or horizontal direction by a KES type pure bending tester is 0.5N ·
The heat-sensitive stencil printing base paper according to claim 1, wherein the base paper is at least cm / cm. 3. The polyester film having a thickness of 0.1 to 0.1.
The heat-sensitive stencil sheet according to claim 1 or 2, wherein the thickness is 5 µm. 4. The melting point of the polyester film is 230 ° C.
The base paper for heat-sensitive stencil printing according to any one of claims 1 to 3, wherein: 5. The heat-sensitive stencil printing paper according to claim 1, wherein the polyester film and the porous support are bonded together without using an adhesive. 6. The heat-sensitive stencil sheet according to claim 1, wherein the porous support is made of a polyester fiber. 7. The polyester fiber has an average diameter of 0.5 to 0.5.
The heat-sensitive stencil sheet according to claim 6, which has a thickness of 20 µm.