JPH08164683A - Base paper for thermosensible mimeographing - Google Patents

Abstract

PURPOSE: To carry out high precision and high quality printing by making base paper for themosensible mimeographing specifying a film orientation parameter for a part of adhesion to support fibers which is obtained by a laser-Raman spectroscopic method. CONSTITUTION: Base paper for thermosensible mimeographing is prepared by gluing a polyester film and a porous support made from synthetic fibers. In this process, it is necessary that a film orientation parameter (R1) for a part of adhesion to the support fibers which is obtained by a laser-Raman spectroscopic method is lower than that (R2) for a non-adhesion part, and the difference between them is made 0.10 or greater. Synthetic fibers of polyester, polyamide, polyphenylene sulfide, polyacrylonitrile, etc., are applicable. The polyester which can be used preferably for the film and the support fibers is made from aromatic dicarboxylic acid, aliphatic dicarboxylic acid, other acids and dial as main components.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat-sensitive stencil printing base paper. More specifically, it relates to a halogen lamp, a xenon lamp, a flash bulb or the like for flash or infrared irradiation, or a pulsed irradiation of a laser beam or the like, and further relates to a heat sensitive stencil printing base paper which is perforated by a thermal head or the like, particularly a thermal head. The present invention relates to a heat-sensitive stencil printing base paper which is excellent in perforation plate-making property and printability and is excellent in transportability.

[0002]

2. Description of the Related Art Thermal stencil printing has been known as a simple printing method replacing conventional copying machines. In heat-sensitive stencil printing, an ink-permeable porous support laminated with a thermoplastic resin film is used as the base paper, and the image of the document read by the sensor is sent to the thermal head as a digital signal.
The thermoplastic resin film is heated and melted by the heat generated by the thermal head to form a perforated plate, and the printing ink is leached from the porous support side into the perforated portion to print on a printing paper.

In recent years, thermal stencil printing is required to have high image quality and high-definition printing performance like offset printing. Also,
It is required to reduce the plate making time and improve the printing speed.

Conventionally, as a base paper for heat-sensitive stencil printing, acrylonitrile film, polyester film,
Thermoplastic resin film such as vinylidene chloride film has a structure in which 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 is bonded with an adhesive. Known (for example, JP-A-51-2512, JP-A-51-2513, and JP-A-57-182495).

However, the conventional heat-sensitive stencil printing base paper has drawbacks such as white spots occurring in solid black portions and fine letters fading. The following are possible causes of poor printability of conventional base paper.

(1) Permeation of ink is hindered by the adhesive agent that bonds the film and the porous support together.

(2) Since the support fiber is thick, the perforated portion of the film is blocked by the fiber and the ink transmission is impeded.

(3) The perforating property of the film is poor, and unperforated portions are generated, so that the plate making faithful to the original cannot be performed.

Various proposals have been made so far in order to improve these drawbacks. For example, JP-A-58-14
7396 and JP-A-4-232790,
As a method of reducing the amount of the adhesive used as much as possible or not using the adhesive, Japanese Patent Laid-Open No. 4-212891 discloses a thermosensitive resin composition in which synthetic fibers are sprinkled on one surface of a thermoplastic resin film and thermocompression bonded. Stencil paper has been proposed.

Further, Japanese Patent Publication No. 63-59394 proposes to reduce the amount of fibers in the support as much as possible or to make the fibers as thin as possible.

Further, Japanese Patent Laid-Open No. 3-65280 discloses a heat-sensitive stencil printing base paper in which the thickness of a film can be specified and punched by a thermal head.

However, none of these conventional base papers was satisfactory for high-definition and high-quality printing similar to offset printing. Further, there is a limit in improving the plate making speed and the printing speed.

[0013]

DISCLOSURE OF THE INVENTION The present invention provides a heat-sensitive stencil having high-definition and high-quality printability similar to offset printing, which cannot be realized by the conventional base paper for heat-sensitive stencil printing, and is excellent in transportability. The purpose is to provide a base paper for printing.

[0014]

As a result of intensive studies to solve the above problems, the present inventors have found that the defects of the conventional base paper can be improved by specifying the degree of orientation of the film constituting the base paper. The invention has been completed.

That is, according to the present invention, in a heat-sensitive stencil printing base paper obtained by adhering a polyester film and a porous support made of synthetic fiber, the film orientation at the adhesion portion with the support fiber obtained by laser Raman spectroscopy. The heat sensitive stencil sheet is characterized in that the parameter (R1) is lower than the film orientation parameter (R2) in the non-adhesive part and the difference is 0.10 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, a copolymer of hexamethylene terephthalate and cyclohexane dimethylene terephthalate, and the like. . Particularly preferred for improving the perforation sensitivity are a copolymer of ethylene terephthalate and ethylene isophthalate, a copolymer of hexamethylene terephthalate and cyclohexane dimethylene terephthalate, and the like.

In the polyester film of the present invention, 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, a wax, or a polysiloxane. The defoaming agent, etc. can be added. Further, slipperiness can be imparted, if necessary. 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, a method of so-called internal particles for depositing a catalyst or the like added during the polyester polymerization reaction, a method of applying a surfactant, and the like.

As the synthetic fiber in the present invention, conventionally known fibers such as polyester, polyamide, polyphenylene sulfide, polyacrylonitrile, polypropylene, polyethylene or copolymers thereof can be used. These synthetic fibers may be used alone, or may be used in combination of two or more kinds, and may contain natural fibers and regenerated fibers, but polyester fibers are particularly preferably used from the viewpoint of support strength. To be Preferable examples of the polyester used for the polyester fiber include polyethylene terephthalate, polyethylene naphthalate, polycyclohexanedimethylene terephthalate, and a copolymer of ethylene terephthalate and ethylene isophthalate. Particularly preferable from the viewpoint of thermal dimensional stability,
Examples thereof include polyethylene terephthalate and polyethylene naphthalate.

The synthetic fiber in the present invention may optionally contain 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, a wax, or a polysiloxane. The defoaming agent, etc. can be added.

The polyesters preferably used in the film and the support fiber of the present invention are polyesters containing aromatic dicarboxylic acid, aliphatic dicarboxylic acid or alicyclic dicarboxylic acid and diol as main constituent components. 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′-diphenylsulfone dicarboxylic acid and the like, and among them, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid and the like are preferable. Examples of the aliphatic dicarboxylic acid component include adipic acid, suberic acid, sebacic acid, dodecanedioic acid and the like, and of these, adipic acid and the like are preferable. Examples of the alicyclic dicarboxylic acid component include 1,4-cyclohexanedicarboxylic acid. These acid components may be used alone or in combination of two or more, and further, an oxy acid such as hydroxybenzoic acid may be partially copolymerized. Examples of the diol component include 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,
Examples thereof include diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2'bis (4'-β-hydroxyethoxyphenyl) propane and the like. Among them, ethylene glycol is preferably used. Only one of these diol components may be used.
You may use together 1 or more types.

The polyester preferably used in the present invention 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, a conventionally known alkali metal, alkaline earth metal, manganese, cobalt, zinc, antimony, germanium, titanium compound or the like can be used as a reaction catalyst.

The polyester film in the present invention is
Orientation parameter (R1) at the bond with the support fiber
Is lower than the orientation parameter (R2) of the portion not bonded to the support fiber, and the difference is preferably 0.10 or more, more preferably 0.20 or more, and particularly preferably 0.50 or more. The maximum value of the difference is preferably 5.0 or less, more preferably 3.0 or less.

In the present invention, the orientation parameters (R1, R2) of the film are Jobin Yvon / Atago Bussan "Ramanor" U-1000I (light source: NEC GLG3300 Ar ⁺ laser 514.5 nm, microscope: Olympus BH-). Type 2 objective lens x 10
Ratio of the peak intensity (I) of the 1615 cm ⁻¹ band in the cross-sectional direction of the film and the peak intensity (I _ND ) of the 1615 cm ⁻¹ band in the thickness direction of the film, which was determined by laser Raman spectroscopy using , I / _IND . The larger the value of the orientation parameter, the higher the degree of orientation of the film.

The orientation parameter of the film of the present invention is determined by embedding the base paper of the present invention in PMMA resin, wet-polishing the cross section thereof, and using the above-mentioned apparatus, a portion bonded to a support fiber and its vicinity. The Raman spectrum of the film portion of the non-adhesive portion was measured and determined. The measurement of R1 and R2 was carried out at 10 or more points on one sheet of base paper, and the average value was calculated.

Further, the polyester film of the present invention is
Orientation parameter R2 of the part not adhered to the support fiber
Is preferably 1.5 or more, more preferably R2
Is 2.0 or more. When R2 is 1.5 or more, the thermal perforation of the thermal head develops a stress capable of sufficiently shrinking the film.

The thickness of the polyester film in the present invention is usually 0.1 to 10 μm, preferably 0.1.
˜5.0 μm, more preferably 0.1 to 3.0 μm. If the thickness is 10 μm or less, the perforation sensitivity does not decrease, and if it is 0.1 μm or more, the film forming stability is good.

The polyester film in the present invention is
The crystal melting energy (ΔHu) is preferably 3 to 11 cal / g, more preferably 5 to 10 cal / g.
Is. When ΔHu is 3 cal / g or more, the perforation sensitivity of the film is stable, and when ΔHu is 11 cal / g or less, no perforation occurs in the film.

The fiber basis weight of the porous support constituting the base paper of the present invention is usually ² to 20 g / m ² , preferably ^{2 to} 16 g / m ² , and more preferably ² to 14 g / m ² . . When the basis weight is 20 g / m ² or less, the ink permeability is high and the image clarity is good. Also, the basis weight is 2
When it is g / m ² or more, the ink holding property is good, and sufficient strength as a support can be obtained, so that a base paper having excellent transportability can be obtained.

The average diameter of the fibers constituting the porous support of the present invention is usually 0.5 to 30 μm, preferably 1 to 20.
μm, more preferably 1 to 10 μm. When the average diameter is 30 μm or less, the thickness and the basis weight of the support are likely to be uniform, and the ink transmission is uniform. Further, when the average diameter is 0.5 μm or more, sufficient strength as a support can be obtained, so that a base paper excellent in transportability can be obtained.

The fibers constituting the porous support of the present invention may all have the same diameter, or may be those in which fibers having different fiber diameters are mixed. Further, a multi-layer structure in which fibers having different fiber diameters are laminated stepwise may be used. In the case of a multilayer structure, at least the layer facing the film should be 10μ
It is more preferable to use fibers of m or less and the remaining layers of fibers of 10 μm or more in terms of the balance between image clarity and support strength. In the case of a multi-layer structure, the fiber unit weight of the layer facing the film is more preferably 1 to 5 g / m ² .

The fibers constituting the porous support of the present invention are particularly preferably stretch-oriented. Degree of fiber orientation (Δ
n) is usually 0.1 or more, preferably 0.12 or more, more preferably 0.14 or more. When the degree of orientation is 0.1 or more, the fiber strength is high and sufficient support strength is obtained, so that a master having excellent transportability can be obtained.

The crystallinity of the fibers constituting the porous support of the present invention is usually preferably 20% or more, more preferably 30% or more, and particularly preferably 35% or more.
When the crystallinity is 20% or more, sufficient heat resistance as a support can be obtained.

The support fiber in the present invention may contain an acid on the surface of the fiber, if necessary, in order to impart an affinity with the ink.
Chemical treatment with alkali, corona treatment, low-temperature plasma treatment, or the like may be performed.

Any method can be adopted to bring the base paper of the present invention into the above range. In particular, an unstretched polyester film and a porous support made of unstretched synthetic fibers are heat-bonded and co-stretched. This is most preferably achieved.

The porous support made of synthetic fiber used in the present invention can be produced by a direct melt spinning method such as a conventionally known melt blow method or spun bond method. The intrinsic viscosity of the polymer used is usually preferably 0.3 or more, more preferably 0.4 or more.

For example, in the melt blow spinning method, when the molten polymer is discharged from the spinneret, hot air is blown from the periphery of the spinneret, the discharged polymer is made finer, and then the net conveyor is placed at an appropriate position. It is manufactured by spraying it onto the surface to form a web. Since the web is sucked together with the hot air by the suction device provided on the net conveyor, it is collected before the fibers are completely solidified. That is, the fibers of the web are collected while being fused to each other. By appropriately setting the collection distance between the die and the net conveyor, the fusion degree of the fibers can be adjusted. Further, the fiber diameter of the web can be arbitrarily set by appropriately setting the polymer discharge amount, the hot air temperature, and the hot air flow rate, and the fiber basis weight of the web can be arbitrarily set by appropriately adjusting the conveyor speed. The fibers melt-spun are finely pulverized by hot air pressure but not stretched and solidified in a so-called non-oriented state.

Similarly, in the spunbond method, the polymer discharged from the die is pulled by an air ejector, and the obtained filament is collided with a collision plate to open the fiber,
It is manufactured by collecting it on a conveyor to form a web. By appropriately setting the pressure and flow rate of the ejector, the degree of fiber orientation can be adjusted, and by reducing the pressure and flow rate to reduce the spinning speed, a fiber web having a low degree of orientation can be obtained. Further, by adjusting the cooling rate of the discharged polymer, fiber webs having different crystallinity can be obtained.

For example, the crystallinity of the unstretched fibers preferably used in the present invention is preferably 20% or less, more preferably 15% or less, in order to ensure sufficient adhesion to the film.
It is particularly preferably 10% or less. Further, the degree of orientation of the unstretched fiber is usually preferably Δn = from the viewpoint of co-stretchability.
It is 0.03 or less, more preferably 0.2 or less, and particularly preferably 0.1 or less.

The polyester film in the present invention is
An unstretched film can be produced by extruding a polymer onto a cast drum by a conventionally known 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. The intrinsic viscosity of the polyester is usually preferably 0.5 or more, more preferably 0.6 or more. When the intrinsic viscosity is 0.5 or more, the film-forming stability is good, and it is particularly easy to cast a thin product.

The polyester film and the porous support made of synthetic fiber in the present invention are preferably fused to each other. For fusion, it is generally preferable to perform thermocompression bonding under pressure while heating the polyester film and the porous support. The method of thermocompression bonding is not particularly limited, but thermocompression bonding with a heating roll is particularly preferable from the viewpoint of processability. In this case, the heating roll is preferably a combination of a metal roll and a rubber roll such as silicone. The temperature during thermocompression bonding is preferably between the glass transition point (Tg) of the polyester film and the cold crystallization temperature (Tcc). The pressure is 0.1-10 kg / c in roll linear pressure.
It is preferable to carry out in the range of m.

In the present invention, it is preferable that the unstretched polyester film and the unstretched porous support are co-stretched in a state of being thermocompression bonded. By co-stretching in the thermocompression bonded state, the film and the support are suitably stretched without peeling. At this time, by appropriately adjusting the thermocompression bonding condition and the stretching condition, the degree of orientation of the film after co-stretching becomes different between the portion bonded to the support fiber and the non-bonded portion.

At this time, the fibers of the support are fused together at a part of the contact points between the fibers to form a mesh-like body. Further, at some of the fusion points, a thin film extending between the fibers is formed. That is,
By forming the porous support in this way,
The strength of the support is stable. Furthermore, by co-stretching the both together, the fibers of the support function as a reinforcing member, so that the film is not broken and the film forming stability is extremely excellent.

The method of co-stretching is not particularly limited and may be either uniaxial stretching or biaxial stretching, but in the present invention, in terms of the degree of orientation of the film and the uniform dispersibility of the support fibers. Biaxial stretching is more preferred. The biaxial stretching may be either a sequential biaxial stretching method or a simultaneous biaxial stretching method, but in the present invention, the sequential biaxial stretching is preferred. In the case of the sequential biaxial stretching, it is general that after the longitudinal stretching by the heating roll group, the transverse stretching is generally performed by the tenter, but it may be reversed. As the heating roll, a metal roll, a ceramic roll, a silicone rubber roll, or the like is used, but stretching is preferably performed between the ceramic rolls, between the ceramic and the rubber rolls, or between the rubber rolls. Also,
The nip pressure during stretching is preferably linear pressure in the range of 0.1 to 10 kg / cm. In the case of polyester resin, the stretching temperature is glass transition temperature (Tg) and cold crystallization temperature (Tc).
It is preferably between c). Further, in order to uniformly heat the film during stretching, only the support fibers may be preheated before being supplied. The stretching ratio is not particularly limited, but in the case of a polyester film, it is usually preferable that the length and the width are 2 to 2 respectively.
It is 8 times, more preferably 3 to 8 times. Further, after biaxial stretching, it may be re-stretched longitudinally or laterally or longitudinally and laterally.

After that, the base paper of the present invention after biaxial stretching may be heat-treated. The heat treatment temperature is not particularly limited and is appropriately determined depending on the type of polymer used, but in the case of a polyester film, it is usually preferably between the glass transition temperature (Tg) and the melting point (Tm) of the polymer,
A suitable treatment time is usually about 0.5 to 60 seconds.

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.
When such aging is adopted, curling and wrinkling are less likely to occur during storage of the base paper or in the printing machine, which is particularly preferable.

The porous support constituting the base paper of the present invention is
The fibers form a reticulated body having fusion points where the fibers are fused to each other at their entanglement points and contact points. Characteristically, at some of the fusion points in the reticulate body, a thin film extending over two or more fibers is formed. That is, since the fibers of the support are formed into a mesh-like body having a fusion point formed by forming a thin film, the strength of the support is stabilized and a uniform open pore shape can be formed. ,
The base paper is excellent in transportability and has a good balance between printing ink retention and permeability.

In the present invention, the film having a thin fusion-bonding point means a so-called "duck's foot watering" shape, or "frog's foot watering" shape, or a "fold" shape, usually two or more. It is formed so as to straddle between the fibers, and its thickness is smaller than the average diameter of the fibers.

The melting point (Tm1) of the thermoplastic resin film constituting the base paper of the present invention and the melting point (Tm2) of the thermoplastic resin fibers forming the porous support are preferably Tm1≤
Tm2, more preferably the temperature difference is 5 ° C or more,
It is particularly preferably 20 ° C. or higher. When Tm1≤Tm2, the perforability of the film is good and the heat resistance of the support is sufficient.

The peel strength between the thermoplastic resin film constituting the base paper of the present invention and the porous support is preferably 1 g / c.
m or more, more preferably 5 g / cm or more, and particularly preferably 10 g / cm or more. When the peel strength is 1 g / cm or more, wrinkles and tears are less likely to occur during the transport of the film,
Excellent running stability.

In the base paper of the present invention, it is preferable to apply a release agent to the film surface in order to prevent fusion with a thermal head or the like. As a release agent, silicone oil,
Conventionally known materials such as silicone-based resins, fluorine-based resins, and surfactants can be used, but the following release agents are particularly preferable.

That is, a release agent containing a mixture of a petroleum wax (A), a vegetable wax (B) and an oily substance (C) which is soluble, emulsified or suspended in water as a main component is particularly preferable. Here, the main component means that the weight ratio of the mixture of (A), (B) and (C) is 50% or more, preferably 60% or more.

Examples of petroleum waxes include paraffin wax, microcrystalline wax, and oxidized wax. Of these, the use of oxidized wax is particularly preferable.

Examples of the vegetable wax include candela wax, carnaupa wax, wood wax, oliqury wax, sugar cane wax and the like. In the present invention, a composition comprising the following compounds is particularly preferable.

That is, {rosin or disproportionated rosin,
Or hydrogenated rosin / α / β-substituted ethylene (α-substituent: carboxyl, β-substituent: hydrogen, methyl or carboxyl) additive} / alkyl or alkenyl (each having 1 carbon atom)
~ 8) It is particularly preferred to use ester additives of poly (repeating units: 1-6) alcohol.

The mixing ratio of petroleum wax and vegetable wax is 10/90 to 90/10% by weight, preferably 20.
/ 80 to 80/20% by weight, more preferably 30/7
It is preferably from 0 to 70/30% by weight. The reason why the vegetable wax is 10% by weight or more is that it has good uniform dispersibility when emulsified or suspended in water and is suitable for obtaining a uniform coating film. Further, when the amount of the petroleum wax is 10% by weight or more, the coating film has good slipperiness and good running property at high speed perforation.

In the present invention, a mixture of the petroleum wax (A) and the vegetable wax (B) to which an oily substance is further added is used. Here, the oily substance is a liquid or paste at room temperature. Oil, vegetable oil,
Examples thereof include fats and oils, mineral oils, synthetic lubricating oils and the like. As vegetable oil, linseed oil, kaya oil, saffron oil, soybean oil,
Examples include cinnamon oil, sesame oil, corn oil, rapeseed oil, bran oil, cottonseed oil, olive oil, southern oil, camellia oil, castor oil, peanut oil, balm oil, and coconut oil. Fats and oils include beef tallow, pork oil, sheep oil, cacao oil and the like, and mineral oils include machine oil, insulating oil, turbine oil, motor oil, gear oil, cutting oil, liquid paraffin and the like.
As the synthetic lubricating oil, those satisfying the requirements described in Encyclopedia of Chemistry (Kyoritsu Publishing Co., Ltd.) can be arbitrarily used, and examples thereof include olefin polymerized oil, diester oil, polyalkylene glycol oil, and silicone oil. it can. Among these, mineral oil and synthetic lubricating oil are preferable. Also,
A mixed system of these may be used.

The oily substance (C) is added in an amount of 1 to 100 parts by weight, preferably 3 to 50 parts by weight, based on 100 parts by weight of the mixture of the petroleum wax (A) and the vegetable wax (B). . When the amount of the oily substance is 1 part by weight or more, the running property in the high applied energy region is good. Further, when the amount is 100 parts by weight or less, the running property in the low applied energy region is good.

When a mixture of a vegetable wax, a petroleum wax and an oily substance is used, a uniform coating film can be easily obtained, as compared with the case where any one of them is used alone.
Good running performance and less sticking.

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 dispersion aids, surfactants, preservatives and defoaming agents may be added to the coating composition for the purpose of improving dispersibility in water.

The thickness of the release agent layer is preferably 0.005 μm.
m or more and 0.4 μm or less, and more preferably 0.01 μm or more and 0.4 μm or less. The release agent layer has a thickness of 0.4 μm
If it is below, the running property at the time of perforation is good and the contamination of the head is small.

When the release agent layer is applied in the present invention, the coating liquid is preferably a coating liquid dissolved, emulsified or suspended in water from the viewpoint of explosion proof and environmental pollution.

The release agent may be applied at any stage before or after stretching the film. In order to bring out the effect of the release agent more remarkably, it is particularly preferable to apply it before stretching. The coating method is not particularly limited, but it is preferable to use a roll coater, a gravure coater, a reverse coater, a bar coater or the like.

If necessary, the coating surface may be subjected to a corona discharge treatment in air or other various atmospheres before the release agent is applied.

[0065]

[Characteristic measuring method] (1) Film orientation parameters (R1, R2) Film orientation parameters (R1, R2) were obtained by embedding the base paper of the present invention in PMMA resin and polishing the film in the cross-sectional direction. , Jobin Yvon / "Ram" manufactured by Atago Bussan
anor "U-1000I (light source: NEC GLG33
00 Ar ⁺ laser 514.5 nm, microscope: Olympus BH-2 type objective lens × 100) was used for laser Raman spectroscopy. The orientation parameter R was defined as follows from the peak intensity (I) of the 1615 cm ⁻¹ band in the cross-sectional direction of the film and the peak intensity (I _ND ) of the 1615 cm ⁻¹ band in the film thickness direction.

R = I / _IND Orientation parameter R is R1 which is the orientation parameter of the film at the portion bonded to the support fiber, and R2 which is the orientation parameter of the film at the portion which is not bonded to the support fiber.
In each case, the average value of 10 or more measurement points was used.

(2) Melting point (Tm, ° C) Differential scanning calorimeter RDC220 manufactured by Seiko Instruments Inc.
Using the mold, collect 5 mg of sample and raise the temperature from room temperature to 20
It was determined from the peak temperature of the endothermic curve when the temperature was raised at ° C / min.

(3) Crystal Melting Energy (ΔHu) Differential Scanning Calorimeter RDC220 manufactured by Seiko Instruments Inc.
It is determined from the area of the film when it is melted using a mold. This area is the area from the baseline to the absorption side by increasing the temperature, and the area until returning to the position of the baseline when the temperature is further increased. Find (a). Same DSC
In (indium) was measured under the condition of
Is calculated to be 6.8 cal / g by the following formula.

6.8 × a / b = ΔHu (cal / g)

(4) Fiber diameter (μm) An arbitrary portion of the sample was photographed with an electron microscope at a magnification of 2000 times, and the diameter of any 5 fibers was measured per photograph, and a total of 150 fibers were measured. The fiber diameter was measured and the average value was calculated.

(5) Fiber areal weight (g / m ² ) The sample was cut into 20 cm × 20 cm, and its weight was measured and converted into weight per m ² .

(6) Intrinsic viscosity [η] After the sample was dried at 105 ° C. for 20 minutes, 6.8 ± 0.00
5 g was weighed and 160 ° C x 1 in o-chlorophenol
It was dissolved by stirring for 5 minutes. After cooling, the viscosity at 25 ° C. was measured with a Yamatrabotic AVM-10S type automatic viscosity meter.

(7) Crystallinity (%) A sample was placed in a density gradient tube made of a mixture of n-heptane and carbon tetrachloride, and the value was read after 10 hours or more to obtain the density. The density of crystallinity 0% is 1.335 g / c
m ³ , density of 100% crystallinity 1.455 g / cm ³
As, the crystallinity of the sample was calculated.

(8) Peel strength (g / cm) Cellophane tape was attached to the film surface for reinforcement, and the peel strength between the film and the porous support was measured according to JIS-K-6854.
The 180-degree peel test method according to

(9) Evaluation of printability The prepared base paper was supplied to a printing machine lithograph (RA205) manufactured by Riso Kagaku Kogyo Co., Ltd., and a black solid (■) with a side of 10 mm was prepared by a thermal head type plate making system. I made a master. Printing was performed with the master, and the density of the printed matter was measured with a Macbeth densitometer and evaluated as follows.

When the density exceeds 1.2, the mark is ◯, and the density is 1.
When the density was less than 1.2, it was evaluated as Δ and when the density was less than 1, it was evaluated as x.

(10) Evaluation of Transportability The master prepared by the above method was observed, and the degree of wrinkling was evaluated as follows.

The ones that could be made without wrinkles at all were 5
A wrinkle of about mm was taken as Δ, and a wrinkle of 5 mm or more was taken as x.

[0079]

EXAMPLES The present invention will now be described in more detail by way of examples.

Example 1 Using a rectangular spinneret having a hole diameter of 0.3 mm and 900 holes, the spinneret temperature was 290 ° C., the hot air temperature was 295 ° C., and the hot air flow rate was 5
A polyethylene terephthalate raw material ([η] = 0.5, Tm = 256 ° C.) was spun by a melt blow method at 00 Nm ³ / h, and fibers were collected and wound on a conveyor at a collection distance of 15 cm to give a fiber areal weight. An unstretched nonwoven fabric of 100 g / m ² was prepared.

Then, polyethylene terephthalate 85
Copolyester resin raw material consisting of mol% and polyethylene isophthalate 15 mol% ([η] = 0.65, T
m = 226 ° C.) is extruded at a T-die mouthpiece temperature of 270 ° C. using an extruder with a screw diameter of 40 mm, and the diameter is 300 mm.
An unstretched film was produced by casting on a cooling drum of

The above non-woven fabric was superposed on the unstretched film and supplied to a heating roll to obtain a roll temperature of 75 ° C. and a linear pressure of 1 k.
After heat bonding at g / cm, and then stretching 3.5 times in the length direction at a nip pressure of 0.5 kg / cm between heating rolls (rubber rolls) at 90 ° C., the mixture was sent to a tenter type stretching machine, and 9
Stretched 4.0 times in the width direction at 5 ° C, and then 1 in the tenter.
It heat-processed at 40 degreeC and produced the heat sensitive stencil base paper. A wax-based release agent was applied to the film surface of the base paper at the entrance of the tenter with a gravure coater in a weight after drying of 0.08 g / m ² . The fiber basis weight of the obtained base paper was 8.5 g / m ² , the average fiber diameter was 4.5 μm, and the film thickness was 1.8 μm. Further, the orientation parameter (R1) of the film in the portion of the base paper which is adhered to the support fiber
Was 4.12, the orientation parameter (R2) of the film in the portion not adhered to the support fiber was 6.23, and the difference was 2.11.

The base paper had good printability and transportability.

Example ² A nonwoven fabric having a fiber areal weight of 140 g / m ² was produced in Example 1.

Then, polyethylene terephthalate 78
Copolyester resin raw material ([η] = 0.66, T
m = 220 ° C.) is extruded at a T-die mouthpiece temperature of 270 ° C. using an extruder with a screw diameter of 40 mm, and the diameter is 300 mm.
An unstretched film was produced by casting on a cooling drum of

The above-mentioned non-woven fabric was superposed on the unstretched film and supplied to a heating roll to obtain a roll temperature of 75 ° C. and a linear pressure of 0.
After heat-bonding at 5 kg / cm, and then stretching at a nip pressure of 1 kg / cm by 3.6 times in the length direction between heating rolls (rubber rolls) at 90 ° C., it is sent to a tenter type stretching machine,
It was stretched 4.6 times in the width direction at 95 ° C. and further heat-treated at 120 ° C. in a tenter to prepare a heat-sensitive stencil sheet. A wax-based release agent was applied to the film surface of the base paper at the entrance of the tenter with a gravure coater in a weight after drying of 0.08 g / m ² . The fiber basis weight of the obtained base paper was 9.0 g / m ² , the average fiber diameter was 5.2 μm, and the film thickness was 1.2 μm. Further, the orientation parameter (R1) of the film in the portion of the base paper which is adhered to the support fiber
Was 5.0, the orientation parameter (R2) of the film in the portion not adhered to the support fiber was 6.8, and the difference was 1.8.

The base paper had good printability and transportability.

Comparative Example 1 A non-woven fabric having a basis weight of 100 g / m ² prepared in Example 1 was prepared. The nonwoven fabric was stretched 3.5 times in length and width by a stretcher and heat-treated at 160 ° C. for 1 minute to prepare a porous support having an average fiber diameter of 7 μm and a fiber areal weight of 7.8 g / m ² .

Next, the same polyethylene terephthalate 85 mol% and polyethylene isophthalate 15 as in Example 1 were used.
A copolyester resin composed of mol% was biaxially stretched to prepare a 1.8 μm-thick polyester film. The porous support and the polyester film were attached using a vinyl acetate resin. Adhesive coating amount is 1g / m ²
And Next, a silicone release agent was applied to the film surface at a weight after drying of 0.06 g / m ² to prepare a heat-sensitive stencil sheet.

The orientation parameter (R1) of the film in the portion of the base paper adhered to the support fibers was 5.81, and the orientation parameter (R1 of the film in the portion not adhered to the support fibers (R
2) was 5.78.

The printability and transportability of the base paper were x.

Example 3 A polyethylene terephthalate raw material ([η] = 0.65, Tm) was prepared using a die having a hole diameter of 0.25 mm and 100 holes.
= 254 ° C.) was melted at a melting temperature of 290 ° C. and dispersed and collected on a conveyor by an air ejector at a spinning speed of 900 m / min to prepare a low orientation nonwoven fabric having a fiber basis weight of 100 g / m ² .

Then, the same polyethylene terephthalate as in Example 1 (85 mol%), polyethylene isophthalate 1
Using a extruder having a screw diameter of 40 mm, a T-die die temperature of 280
It was extruded at 0 ° C. and cast on a cooling drum having a diameter of 300 mm to prepare an unstretched film.

The above non-woven fabric was laid on the unstretched film and supplied to a heating roll to obtain a roll temperature of 80 ° C. and a linear pressure of 2 k.
A laminated sheet was produced by thermocompression bonding at g / cm.

The laminated sheet was heated between 95 ° C. heating rolls (rubber rolls) at a nip pressure of 3 kg / cm in the lengthwise direction.
After stretching 0 times, it was fed into a tenter type stretching machine and stretched 3.3 times in the width direction at 95 ° C. 15 inside the tenter
Heat treatment was performed at 0 ° C. to prepare a heat sensitive stencil sheet. At the entrance of the tenter, the wax-based release agent was applied to the film surface using a gravure coater, and the weight after drying was 0.08 g.
/ M ^{2 was} applied.

The fiber basis weight of the obtained base paper was 11.0 g /
m ² , average fiber diameter 10 μm, film thickness 2.0
μm.

The orientation parameter (R1) of the film in the portion of the base paper adhered to the support fibers was 3.54, and the orientation parameter (R2) of the film in the portion not adhered to the support fibers was 4.57. Yes, the difference was 1.03.

The printability and transportability of the base paper were good.

Example 4 The fiber basis weight was changed to 60 g / m by changing the conveyor speed in Example 3.
^Two non-woven fabrics were prepared.

Then, polyethylene terephthalate 78
Copolyester resin raw material ([η] = 0.66, T
m = 220 ° C.) is extruded at a T-die mouthpiece temperature of 270 ° C. using an extruder with a screw diameter of 40 mm, and the diameter is 300 mm.
An unstretched film was produced by casting on a cooling drum of

The above non-woven fabric was superposed on the unstretched film and supplied to a heating roll to obtain a roll temperature of 75 ° C. and a linear pressure of 0.
It is heat-bonded at 2 kg / cm, then stretched 2.2 times in the length direction at a nip pressure of 1.5 kg / cm between heating rolls (rubber rolls) at 90 ° C., and then sent to a tenter type stretching machine at 95 ° C. It was stretched 2.5 times in the width direction and further heat-treated at 120 ° C. in a tenter to prepare a heat-sensitive stencil sheet. On the film side of the base paper, at the tenter inlet,
A wax-based release agent was applied by a gravure coater to a weight of 0.08 g / m ² after drying. The fiber basis weight of the obtained base paper was 12.0 g / m ² , the average fiber diameter was 16 μm, and the film thickness was 2 μm. Further, the orientation parameter (R1
) Was 2.73, and the orientation parameter (R2) of the film in the portion not adhered to the support fiber was 3.21, and the difference was 0.48.

The printability and transportability of the base paper were good.

Comparative Example 2 In Example 4, the longitudinal and transverse stretching ratios were 1.7 times,
A heat-sensitive stencil base paper was prepared with 1.9 times.

The orientation parameter (R1) of the film in the portion of the base paper adhered to the support fiber was 1.35, and the orientation parameter (R1 of the film in the portion not adhered to the support fiber was R).
2) was 1.40.

The printability and transportability of the base paper were x.

Comparative Example 3 The nonwoven fabric having a basis weight of 100 g / m ² prepared in Example 3 was prepared. The nonwoven fabric was stretched 3 times in length and width by a stretcher and heat-treated at 160 ° C. for 1 minute to prepare a porous support having an average fiber diameter of 12 μm and a fiber basis weight of 11 g / m ² .

Then, the same polyethylene terephthalate 78 mol% and polyethylene isophthalate 22 as in Example 2 were used.
A copolymerized polyester resin composed of mol% was biaxially stretched to prepare a polyester film having a thickness of 2.0 μm. The porous support and the polyester film were attached using a vinyl acetate resin. Adhesive coating amount is 1g / m ²
And Next, a silicone release agent was applied to the film surface at a weight after drying of 0.06 g / m ² to prepare a heat-sensitive stencil sheet.

There is no difference between the orientation parameter (R1) of the film of the part of the base paper which is adhered to the support fiber and the orientation parameter (R2) of the film of the part which is not adhered to the support fiber. there were.

The printability and the transportability of the base paper were x and Δ, respectively.

Comparative Example 4 In Comparative Example 3, the porous support and the polyester film were heat-bonded without using an adhesive.

The orientation parameter (R1) of the film in the portion of the base paper adhered to the support fibers was 5.0, and the orientation parameter of the film in the portion not adhered to the support fibers (R2)
) Was 4.9.

The printability and transportability of the base paper were x.

As can be seen from the above results, the base paper of the invention in which the orientation parameter R1 of the film in the portion bonded to the support fiber is lower than the orientation parameter R2 of the film in the portion not bonded to the support fiber is Excellent printability and transportability.

[0114]

The present invention has the above-mentioned structure,
The following effects are obtained. That is, in plate making such as a thermal head, the perforated portion of the film can have a uniform opening form, so that a plate making master faithful to the original can be obtained. Therefore, the printed matter obtained by stencil printing using this base paper has high definition and high image quality, and is excellent in printing sharpness. Further, wrinkles and the like do not occur during perforation plate making in the printing machine, and the transportability is excellent.

Claims (3)

[Claims] 1. In a heat-sensitive stencil printing base paper obtained by adhering a polyester film and a porous support made of synthetic fiber, a film orientation parameter (R1 at the adhesion part with the support fiber, which is determined by laser Raman spectroscopy. ) Is lower than the film orientation parameter (R2) in the non-adhesive part, and the difference is 0.10 or more, a heat-sensitive stencil printing base paper. 2. The heat-sensitive stencil sheet according to claim 1, wherein the film orientation parameter (R2) at the non-adhesive part is 1.50 or more. 3. The base paper for heat-sensitive stencil printing according to claim 1 or 2, wherein the porous support is composed of fibers mainly composed of polyester.