JPH09300845A - Film for heat-sensitive stencil printing base paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form the perforation diameter in compliance with the variation of energy level and improve tone properties by biaxially orienting a resin composition composed of polyester having respectively specified melting point and glass transition point and the specified temperature difference between the temperature rise crystallization temperature and the glass transition point as a main component. SOLUTION: In a heat-sensitive stencil printing base paper polyester film perforated by the flash emission by digital processing for perforating a thermal head, the laser emission or the like, a halogen lamp or the like, a biaxially oriented resin composition composed of polyester having the melting point (Tm) of 200 deg.C or under, the glass transition point (Tg) of 50 deg.C or above and the temperature difference (ΔTcg:Tcc-Tg) between the temperature rise crysallization temperature (Tcc) and the glass transition point (Tg) is 100 deg.C or under as a main component is used. The film is formed of a resin composition composed of polyester of 70wt.% or more as a main component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester film for heat-sensitive stencil printing base paper which is digitally perforated by a thermal head, laser irradiation, etc. Especially perforation characteristics (perforation sensitivity,
The present invention relates to a polyester film for high-sensitivity heat-sensitive stencil printing base paper, which has excellent independent perforation), printing clarity (character printing, solid printing, gradation), and excellent printing durability and transportability (curl resistance). .

[0002]

2. Description of the Related Art Conventionally, as a base paper for heat-sensitive stencil printing,
A thin paper made of a thermoplastic resin film such as vinylidene chloride film, polyester or polypropylene film, natural fiber, chemical fiber or synthetic fiber, or a mixture of these.
There is known a structure in which a porous support made of a non-woven fabric, gauze or the like is attached with an adhesive (for example, JP-A-51-2512 and JP-A-57-182495).
Issue publication). Films for these heat-sensitive stencil printing papers are perforated by a halogen lamp, a xenon lamp, a flash lamp or the like for flash or infrared irradiation, pulsed irradiation of a laser beam or the like, or a thermal head or the like, and ink is permeated through the above porous support. It becomes a printing plate that passes through.

However, in recent years, a high resolution (gradation) is required for printed matter, and in order to obtain gradation in color in particular, the energy given to the head, that is, the portion heated by the head is required. It has become necessary to be able to change the perforation diameter of the film by changing the temperature distribution of the film. For that purpose, it is necessary to widely change the energy range to be applied to the above-mentioned thermoplastic film, small holes are perforated at low energy, large holes are perforated at high energy, and the holes are kept independent without being connected. (Independent perforation) is important.

In the printing method using a thermal head or the like, attempts have been made to reduce the size of each head and increase the number of heads per unit area in order to obtain high resolution. However, even if the energy supplied to each head is reduced by the size of the head and the energy supplied to the head per unit area is the same as that of the conventional head, the life of each head is small. It will decrease due to It is necessary to further reduce the energy supplied to the individual heads in order to make the life of the heads comparable to conventional ones, and it is necessary for the above-mentioned thermoplastic film to obtain sufficient perforations with low energy. .

Further, as a feature of the stencil printing method, once an original image made by a thermal head or the like is created,
Although it is possible to print a large number of copies at high speed and at low cost, in order to make the best use of this feature, the original image made by plate making should not be torn or stretched by printing a large number of copies (printing durability). Is needed. Regarding the demand for printing durability, the versatility is further increased with the cost reduction of a printing machine for heat-sensitive stencil printing, etc.
At present, the number of fields requiring printing durability of 5000 sheets or more is increasing compared to the printing durability of 00 sheets or more.

On the other hand, when the stencil printing base paper is used in a printing machine, it is also important to suppress the occurrence of conveyance failure due to curling of the base paper (curling resistance), depending on the properties of the support used. .

Conventionally, as a film used for such an application, a film having improved printing characteristics and printing durability by controlling the thermal characteristics of a biaxially stretched polyester film (Japanese Patent Laid-Open No. 62-282984) and heat shrinkage. Films with specified characteristics (Japanese Patent Laid-Open No. 62-282983, Japanese Patent Laid-Open No. 63-160895, Japanese Patent Laid-Open No. 1-97691)
Japanese Patent Laid-Open No. 1-168494, Japanese Patent Laid-Open No. 2-3
No. 07788, No. 3-30996, No. 3-99890, No. 3-288695, No. 3-182395, No. 4-125.
190, JP-A-4-185489, JP-A-4-224952, JP-A-5-77572, JP-A-6-305015, and JP-A-7-525.
No. 72, Japanese Patent Laid-Open No. 7-68964) and the like have been proposed.

[0008]

However, in the above-mentioned conventional techniques, the perforation sensitivity is not sufficient in the low energy region, and the independent perforation property is poor in the high energy region. There is a drawback such as a decrease. That is, although it is required that the film is perforated by reacting sensitively to the difference in temperature, the conventional film has a problem that the reaction to temperature is slow. Further, the printing durability and the curl resistance were not satisfactory at the same time.

The present invention solves the above-mentioned problems of the prior art, has a good perforation property even at low energy, and provides an excellent gradation property by opening a perforation diameter according to a change in energy level, and further, it has excellent durability. An object of the present invention is to provide a film for heat-sensitive stencil printing base paper which is excellent in printing property and curling resistance.

[0010]

That is, the present invention has a melting point (Tm) of 200 ° C. or lower and a glass transition point (Tg) of 5 or less.
A temperature difference (ΔTcg: Tcc-Tg) between the temperature rising crystallization temperature (Tcc) and the glass transition point (Tg) of 10 ° C. or higher is 10
A film for heat-sensitive stencil printing base paper, which is obtained by biaxially stretching a resin composition having a polyester of 0 ° C. or less as a main component.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester used in the film of the present invention is a polyester containing an aromatic dicarboxylic acid or an aliphatic dicarboxylic acid and a diol as main constituent components. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,
Examples thereof include 6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid and 4,4'-diphenylsulfonedicarboxylic acid. As the aliphatic dicarboxylic acid, for example, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, etc. can be used. Among them, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and adipic acid are preferably used. 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, diethylene glycol, triethylene glycol, polyalkylene glycol,
2,2 ′ bis (4′-β-hydroxyethoxyphenyl) propane and the like can be used. Among them, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and 1,4-cyclohexanedimethanol are preferably used.

The polyester used in the present invention may be copolymerized with components other than the dicarboxylic acid component and the diol component constituting the present invention, as long as the effects of the present invention are not impaired. Examples of such components include polyfunctional compounds such as trimellitic acid, trimesic acid, pyromellitic acid, tricarballylic acid, trimethylolpropane, glycerin and pentaerythritol, p-oxybenzoic acid, lactic acid and 3-hydroxybutanoic acid. An oxycarboxylic acid or the like can be used.

The polyester used in the film of the present invention is preferably ethylene terephthalate / ethylene isophthalate copolymer, butylene terephthalate /
Butylene isophthalate copolymer, butylene terephthalate / butylene-2,6-naphthalate copolymer, hexamethylene terephthalate / hexamethylene-2,6-
Naphthalate copolymer, hexamethylene terephthalate / ethylene terephthalate copolymer, cyclohexane dimethylene terephthalate / ethylene terephthalate copolymer, ethylene isophthalate, ethylene-2,6-naphthalate / ethylene terephthalate copolymer, ethylene terephthalate / diethylene terephthalate copolymer Polymers, homopolyesters thereof, binary polyester copolymers, and ternary or higher copolymers may be used. As a specific example of the homopolyester, an oxycarboxylic acid polymer typified by polylactic acid can be used. Further, these copolymers may be random copolymers or block copolymers. Further, it may be a blended body in which two or more kinds of polyesters having different compositions are blended.

The polyester used in the film of the present invention has a melting point (Tm) of 200 ° C. or less and a glass transition point (Tm).
g) is 50 ° C. or higher, the temperature difference between the temperature rising crystallization temperature (Tcc) and the glass transition point (Tg) (ΔTcg: Tcc-Tg).
Should be 100 ° C. or lower.

A film having a polyester melting point (Tm) of more than 200 ° C. requires a large amount of energy for perforation, resulting in poor perforation characteristics at low energy. To improve the perforation characteristics, the film thickness is further increased. When the thickness is reduced, printing durability deteriorates, and it becomes impossible to achieve both punching characteristics and printing durability. The melting point of polyester is 190 ° C or less, and 18
When the temperature is 0 ° C. or less, the perforation property is improved even in a thick film, and the printing durability is further improved, which is preferable.

In the case where two or more melting points, glass transition points, and ΔTcg are present due to the fact that the polyester as the main component in the present invention is a blend, the melting points are the respective melting points measured by DSC. It is necessary that the melting point of the larger crystal melting energy (ΔHu) is 200 ° C. or lower, and it is more preferable that the melting point is not observed at a temperature higher than 200 ° C. Regarding the glass transition point, it is necessary that the glass transition point is not observed below 50 ° C. Further, ΔTcg needs to have a minimum value within the above-mentioned range in the combination of the difference between the temperature rising crystallization temperature and the glass transition point.

The glass transition point (Tg) of polyester is 5
A film having a temperature of less than 0 ° C. has insufficient dimensional stability in a low temperature region near room temperature, and thus curls and causes conveyance failure. By setting the glass transition point of polyester to 55 ° C. or higher, and further 60 ° C. or higher, further curl resistance,
This is preferable because it is easy to achieve both the perforation characteristics and the cost.

Temperature rising crystallization temperature (Tcc) of polyester
Difference between the glass transition temperature and the glass transition point (Tg) (ΔTcg: Tcc
-Tg) is a value indicating the easiness of crystallization of the polyester, and if this value is small, it can be said that the polymer is easily crystallized. When the ΔTcg exceeds 100 ° C., the melting point of the film becomes unclear, and the perforation diameter becomes uneven due to the melting unevenness of the film at the time of perforation, and the target gradation cannot be obtained. The ΔTcg of the polyester is preferably 80 ° C. or lower, more preferably 70 ° C. or lower.
On the other hand, if ΔTcg is too small and crystallization is too easy, crystallization proceeds in the cooling step of the molten polymer after extrusion during film production, resulting in thickness unevenness due to stretching unevenness. In some cases, the pore size becomes uneven, the desired gradation cannot be obtained, or the stretchability decreases, so that the film frequently breaks during the film production and the productivity decreases. From this viewpoint, the value of ΔTcg is preferably 30 ° C. or higher, more preferably 35 ° C. or higher.

The ΔTcg of the polyester of the present invention is 100
The method of controlling the temperature to be not higher than 0 ° C. is not particularly limited, but a method of optimizing the composition of the polyester described above, a method of adding a crystal nucleating agent to the polyester, and a method of adding a plasticizer are preferable. A crystal nucleating agent is a ΔTc of polyester when added.
It is a general term for those which bring about the effect of reducing g, and the crystal nucleating agent can impart appropriate ΔTcg and lubricity at the same time when added as particles for imparting lubricity to the film described later or as internal particles. Therefore, it is preferable.

The polyester in the present invention can be produced, for example, by the following method. That is, a dicarboxylic acid component is directly esterified with a diol component, and then the product of this reaction is heated under reduced pressure to remove excess diol component to cause polycondensation to produce a dicarboxylic acid component. There is a method in which a dialkyl ester is used as the compound, a transesterification reaction is performed with this and a diol component, and then polycondensation is carried out in the same manner as described above. At this time, if necessary, a reaction catalyst can be appropriately used.

In order to achieve the object of the present invention, it is necessary that the resin composition used for the film of the present invention contains a polyester having the above-mentioned properties as a main component. Here, the main component means 50% by weight or more, and may be blended with polyester, polyolefin, polyamide, polycarbonate, polyether or the like which does not satisfy the above-mentioned conditions of polyester in the range of 50% by weight or less. In short, it is preferable that the blending does not significantly deviate from the conditions of the main component polyester described above as the resin composition used in the present invention. That is, when two or more melting points, glass transition points, and temperature rising crystallization temperatures of the resin composition are present by adding a substance other than the main component polyester,
Regarding the melting point, the one having a larger crystal melting energy (ΔHu) at each melting point measured by DSC is preferably 200 ° C. or lower, and more preferably, the melting point is not observed at a temperature higher than 200 ° C. It is preferable that the glass transition point is not observed below 50 ° C. when measured with a film. For example, polypropylene is incompatible with polyester and has a low glass transition point (about 1
If it is a blend of highly crystalline (0 ° C.), good dimensional stability can be maintained near room temperature. More preferably, the glass transition point is not observed below 50 ° C. when the film is once melted and measured as a resin composition.
The temperature rising crystallization temperature is not particularly limited because the main component is the above-mentioned polyester, but when there are a plurality of glass transition points and / or temperature rising crystallization temperatures, the temperature showing the highest glass transition point and From the viewpoint of productivity, it is preferable that the difference from the temperature at which the temperature rise crystallization temperature is low is 30 to 100 ° C. This means that the main component is 50% by weight
The same applies to Further, in the case of a resin composition added with a polyester that does not satisfy the conditions of the above-mentioned main component polyester, a partial transesterification reaction proceeds at the time of melting after the addition, the melting point of the resin composition, the glass transition point, and the temperature rise. Since the crystallization temperature may change, special attention should be paid in the case of compatibility.

The preferred range of the amount of polyester constituting the main component of the resin composition used in the film of the present invention is 70% by weight or more, more preferably 80% by weight or more, and most preferably 90% by weight or more. Further, the polyester may be used alone.

The method for obtaining the resin composition used for the film of the present invention as a blend is not particularly limited,
After the polyester as the main component is mixed in a polymerization reaction vessel, a method of continuously polymerizing or a method of dry blending and melt extrusion can be used.

In addition, the resin composition used in the film of the present invention may optionally contain a flame retardant, a heat stabilizer, a plasticizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a pigment, a fatty acid ester, and a wax. Such an organic lubricant as described above or a defoaming agent such as polysiloxane may be blended, or two or more kinds thereof may be used in combination.

Further, the resin composition used for the film of the present invention may be provided with slipperiness, if necessary. The method for imparting slipperiness is not particularly limited, but for example, clay, mica, titanium oxide, calcium carbonate, kaolin, talc, inorganic particles such as wet or dry silica, acrylic acid-based polymers, polystyrene and the like as constituent components. There is a method of blending organic particles and the like, a method of so-called internal particles, which is formed by deactivating the catalyst and the like added during the polyester polymerization reaction, and a method of applying a surfactant.

The film of the present invention is obtained by biaxially stretching the above-mentioned polymer. An unstretched film melts at the time of perforation, but no hole is formed, so that the perforation property is poor, and since the strength of the film is low, the printing durability is also poor. As the stretching method, an inflation simultaneous biaxial stretching method, a stenter simultaneous biaxial stretching method, a stenter biaxially stretched film according to any one of the sequential biaxial stretching method, among which, film forming stability sex,
From the viewpoint of thickness uniformity, a film formed by a stenter sequential biaxial stretching method is preferably used.

The film of the present invention can be produced by the following method using the above resin composition. That is, an unstretched film can be produced by extruding the resin composition onto a cast drum by the T-die extrusion method. As a method for adhering to the cast drum, any of an electrostatic application method, an adhering method using surface tension of water, an air knife method, a press roll method, an underwater casting method, etc. may be used, but the flatness is As a method for obtaining a film that is good and has few surface defects, it is particularly effective to use a contact casting method utilizing the surface tension of water or an electrostatic application method. At this time, in the resin composition typified by polybutylene terephthalate and polyhexamethylene terephthalate and their copolymers, crystallization at the stage of the cast film is suppressed, and the surface tension of water is adjusted so as not to reduce the subsequent stretchability. It is preferable to quench the molten resin composition by using the contact casting method and the electrostatic application method together. The unstretched film of the desired thickness is the slit width of the die,
It can be produced by adjusting the discharge amount of the resin composition and the rotation speed of the cast drum.

The stretching method is not particularly limited, but in the case of the stenter sequential biaxial stretching method, the stretching in the longitudinal direction is performed at a temperature not lower than the glass transition point of the resin composition, and the stretching ratio is appropriately determined depending on the type of the resin composition used. However, about 2 to 5 times is appropriate.

The width-direction stretching ratio and the stretching temperature are not particularly limited and are appropriately determined depending on the kind of the resin composition used, but the stretching ratio is preferably about 2 to 5 times, and the stretching temperature is long. It is preferable that the stretching temperature is equal to or higher than the stretching temperature in the direction because the stretchability is good.

After the biaxial stretching, the longitudinal direction or width direction of the film, or both of them may be re-stretched.

Further, the polyester film of the present invention may be subjected to heat treatment after biaxial stretching while subjecting it to a fine stretching of 10% or less with respect to the entire width of the film in a constant length and / or a width direction in a low temperature region near room temperature. It is preferable from the viewpoints of dimensional stability of the film and flatness of the film. The heat treatment temperature is preferably in the range of the following formula (1) because the dimensional stability in the low temperature region and the flatness of the film are simultaneously satisfied.

Ttd ≦ Ths ≦ Ttd + 30 (1) (where Ttd is the stretching temperature (° C.) in the width direction and Ths is the heat treatment temperature (° C.)) The more preferable heat treatment temperature is Ttd ≦ Ths ≦ Ttd + 2
0.

The heat treatment time is preferably 0.5 to 60 seconds.

The thickness of the film of the present invention is preferably 0.5 μm or more, more preferably 0.8 μm or more. If the film thickness is less than 0.5 μm, the perforation sensitivity is improved in the low energy region, but the printing durability is poor, the film that becomes the plate is damaged when printing a large number of copies, and the film-forming stability and winding during film production are improved. The processability may be deteriorated, and the yield may be deteriorated in the step of laminating the obtained film and a porous support such as thin paper. The upper limit of the film thickness is not particularly limited, but 4 μm or less is suitable.

Further, when the intrinsic viscosity and surface characteristics of the film obtained in the present invention, that is, the center line average roughness and the maximum roughness are within the ranges described below, the effects of the present invention are more remarkably exhibited, which is preferable.

The intrinsic viscosity of the film of the present invention is preferably 0.6 or more, more preferably 0.65 or more. If the intrinsic viscosity of the film is less than 0.6, productivity may decrease due to film breakage, and the residue of the resin composition melted during perforation may adhere to the thermal head or the like to cause perforation unevenness.

The center line average roughness (R
The range a) is preferably from 0.01 to 0.5 μm, more preferably from 0.05 to 0.4 μm from the viewpoint of stable productivity in the step of producing a raw paper from the film formation, perforation characteristics, and printing clarity. When Ra is less than 0.01 μm, the winding property and the handling property become difficult, and creases may be formed, which may reduce the productivity. On the other hand, if Ra exceeds 0.5 μm, the surface may be roughened so much that the perforation sensitivity may be significantly reduced, or the perforation diameter may be uneven.

The maximum roughness (Rt) of the film of the present invention is
The range of 0.3 to 5 μm is preferable, and more preferably,
It is 0.5 to 4 μm. If Rt is less than 0.3 μm, slipperiness may be deteriorated, air may not be released well and vertical wrinkles may be formed, and the windability and handleability may be deteriorated. On the other hand, when Rt is more than 5 μm, not only the roughening of the surface is so large that the perforation sensitivity is lowered, but also the film is broken and the productivity may be lowered.

In the film of the present invention, the base paper for printing can be manufactured all at once by co-stretching the porous support in a state of being thermocompression bonded. By integrally stretching the film and the support in a thermocompression-bonded state, the porous support serves as a reinforcing body, the film is not broken, and the film formation stability is extremely excellent. It is preferable because a low-cost base paper can be obtained. A polyester-based nonwoven fabric is preferable as the porous support from the viewpoint of stretchability.

Further, in order to improve the film-forming stability, a method of obtaining a biaxially stretched film by peeling and separating from a laminated film with another thermoplastic polymer can be adopted.

The other thermoplastic polymer is not particularly limited, but preferably the peeling force when peeling from the film layer of the present invention is 10 g / cm or less, more preferably 0.1 to 2 g / cm.
cm, more preferably 0.2 to 0.8 g / cm. More specifically, as long as it is different from the resin composition constituting the film of the present invention, specifically, polyester, polyamide, polyolefin, polystyrene, polycarbonate, polyacrylonitrile, polyvinyl alcohol, polyphenylene sulfide, polyacetal. , Polyethers and their copolymers, fluoropolymers, etc. can be used. Among them, polyolefin, polyphenylene sulfide, fluorine-based polymer and the like are preferable. As a typical example of polyolefin,
Although low density polyethylene, medium density polyethylene, high density polyethylene, low density polyethylene, polypropylene, polybutene-1, poly-4-methyl-pentene-1, or copolymers or mixtures thereof can be used,
A copolymer of 80 to 97 mol% of propylene and 3 to 20 mol% of an olefin other than propylene is more preferable.
Further, various release agents such as silicone, petroleum resin, terpene resin, and higher fatty acid wax may be added to these polyolefins. Further, various additives such as antioxidants, antistatic agents, coloring pigments, antiblocking agents, and ultraviolet absorbers may be added.

Specifically, as a method of peeling and separating to obtain a biaxially stretched film, the polyester used in the polyester film of the present invention and another thermoplastic polymer are supplied to different extruders, respectively, and then melted and joined in a die. Crimping, forming into a sheet shape, and extruding into a cast drum shape to produce an unstretched film. At this time, 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, the resin composition (designated as A) and the other thermoplastic polymer (designated as B) constituting the film of the present invention have a two-layer structure of A / B or a three-layer structure of A / B / A. It does not matter which structure is used. The unstretched film thus obtained can be obtained as a biaxially stretched film in the same manner as in the above-mentioned single layer film formation. After that, (A)
By peeling the layer and the layer (B), the intended film of the layer (A) can be obtained. At this time, the porous support may be attached and then peeled.

In the film of the present invention, in order to prevent fusion with a thermal head or the like, a release agent can be applied to one surface of the polyester film before or after the film is stretched, or in the process in the middle thereof. 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.

Before coating, if necessary, the coated surface may be subjected to corona discharge treatment in the air or in various other atmospheres.

As the release agent used in the release agent layer in the polyester film of the present invention, for example, the following agents made of silicone oil, silicone resin, fluorine resin, surfactant, etc. can be used. However, the following release agents are particularly preferable. That is, dissolved in water,
A release agent containing a mixture of an emulsifying or suspending petroleum wax (a), a vegetable wax (b) and an oily substance (c) 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. The wax composition is a commercially available wax, for example, a petroleum wax, a plant wax, a mineral wax,
Animal waxes Low molecular weight polyolefins and the like can be used, and although not particularly limited, paraffin wax, microcrystalline wax, oxide wax, etc. can be used as petroleum waxes. As the vegetable wax, candelilla wax, carnauba wax, wood wax, oliqury wax, sugar cane wax, rosin modified wax and the like can be used. The mixing weight ratio of petroleum wax / vegetable wax is 10/90 to 90/10, preferably 20.
/ 80 to 80/20, more preferably 30/70 to 70
It is preferably / 30. A vegetable wax content of 10% by weight or more is effective for imparting slipperiness and releasability at high temperatures, and for obtaining a uniform coating film having good dispersibility when emulsified or suspended in water. Because it is suitable. Further, when a mixture is prepared by further adding an oily substance to the above wax-based composition, the printing runnability can be made particularly excellent. Here, the oily substance is an oil that is liquid or pasty at room temperature, and vegetable oil, fats and oils, mineral oil, synthetic lubricating oil and the like can be used. As vegetable oil, linseed oil, kaya oil, saffron oil, soybean oil,
It is possible to use cinnamon oil, sesame oil, corn oil, rapeseed oil, bran oil, cottonseed oil, olive oil, southern oil, camellia oil, castor oil, peanut oil, balm oil, coconut oil and the like. Fats and oils include beef tallow, pork oil, sheep oil, cocoa oil, and the like, and mineral oils include machine oil, insulating oil, turbine oil,
Motor oil, gear oil, cutting oil, liquid paraffin, etc. can be used. As the synthetic lubricating oil, those satisfying the requirements described in the Chemical Dictionary (Kyoritsu Publishing Co., Ltd.) can be arbitrarily used. For example, olefin polymer oil, diester oil,
Polyalkylene glycol oil, silicone oil, etc. can be used. Among these, mineral oil and synthetic lubricating oil, which have good running properties in the high pulse width region, are preferable. Also, a mixed system of these may be used.

The above oily substance is preferably added in an amount of 1 to 100 parts by weight, more preferably 3 to 50 parts by weight, based on 100 parts by weight of the wax composition. If the amount of the oily substance is less than 1 part by weight, the running property in a high pulse width region such as that of a sublimation printer tends to decrease, and
On the other hand, if the amount exceeds 100 parts by weight, the running property in the low pulse width region tends to decrease. The above range is particularly preferable because stickiness does not occur in a printer having a wide pulse width and the running property is good.

Various additives may be used in combination in the above composition within a range that does not impair the effects of the present invention. For example, antistatic agents, heat-resistant agents, antioxidants, organic and inorganic particles,
A pigment or the like can be used.

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 punching is good and the contamination of the head is small.

[0049]

[Evaluation Method of Physical Properties and Effects] Each characteristic used in the present invention was measured and evaluated by the following methods.

(1) Melting point (Tm), glass transition temperature (T
g), measurement of temperature rising crystallization temperature (Tcc) Differential scanning calorimeter RDC220 manufactured by Seiko Instruments Inc.
Using a mold, preheat the sample to 280 ° C.,
After holding at 80 ° C. for 5 minutes, it was quenched with liquid nitrogen. Then, once the temperature was raised to room temperature, the temperature was raised from -50 ° C again to 20 ° C.
The temperature was raised at 1 / min to obtain a DSC curve. From the DSC curve at this time, a glass transition point, a temperature rising crystallization temperature as a peak temperature of an exothermic curve, and a melting point as a peak temperature of an endothermic curve were obtained. As for the calculation of ΔTcg, ΔTcg was uniformly judged to exceed 100 ° C. for the samples in which the elevated temperature crystallization temperature was not observed. Here, when measuring the melting point as a film, not as a resin composition, a DSC curve was obtained without the above-mentioned pretreatment, and the peak of the endothermic curve was taken as the melting point.

(3) Crystal melting energy (ΔHu) Obtained from the peak area of the endothermic curve of the DSC curve. 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. In (indium) was measured under the same DSC conditions, and the area (b) was determined as 28.5 J / g by the following equation.

ΔHu = 28.5 × a / b (J / g)

(4) Center line average roughness (Ra) and maximum roughness (Rt) The roughness was measured according to JIS-B0601 using a stylus type surface roughness meter. In addition, using a high precision thin film step measuring instrument (model: ET-10) manufactured by Kosaka Laboratory Ltd., a conical stylus diameter of 0.5 μmR, a load of 5 mg, and a cutoff of 0.08 mm.
And

(5) Intrinsic viscosity After the sample was dried at 105 ° C. for 20 minutes, 0.8 ± 0.00
5 g is weighed, and 160 ° C. × 1 in o-chlorophenol.
It was dissolved by stirring for 5 minutes. After cooling, the viscosity at 25 ° C. was measured with a Yamatra Robotic AVM-10S automatic viscosity meter.

(6) Film Thickness (μm) Ten arbitrary portions of the sample were cut out in the cross-sectional direction, and 10 photographs were taken with an electron microscope at a magnification of 2000 to measure the film thickness. This was performed for 10 photographs and expressed as the average value.

(7) Punching characteristics The prepared base paper is "RISOGRA" manufactured by Ideal Science Industry Co., Ltd.
It was supplied to the PH "GR275, and by a thermal head type plate making method (400 dpi), a JIS 10th standard ● (circle filled in black) was used as an original to make a plate having a diameter of 10 mm. The energy applied to each of the two was 50 μJ and 30 μJ per dot.Perforation was performed in this state, and 200 perforated portions of the film were observed with a scanning microscope at a magnification of 100 times, and the perforation characteristics were evaluated by the following items. did.

A. Perforation sensitivity ◎: Perforation was surely performed and was good ○: There was a small portion where no perforation was obtained, but there was no problem in practical use △: There were portions where perforation was not obtained ×: I can't get the desired perforations at all

B. Independent perforation ◎: It was good because each dot was independently perforated. ○: There was a small portion where each dot was not independently perforated, but there was no problem in practical use. There was a part where each dot was not independently punched x: There are many places where dots are connected next to each other

(8) Printing sharpness Test chart No. 1 manufactured by Ideal Science Co., Ltd. 8 as a manuscript, a base paper prepared using a thermal head of 400 dpi was prepared, and a printing sample was prepared using black ink.
The following characteristics of the image (solid printing) were visually observed and judged.

A. Visibility of character printing ○: No missing characters or uneven thickness Δ: Missing characters, uneven thickness but no problem in practical use ×: Missing characters, uneven thickness, unusable

B. Clearness of solid printing ○: No unevenness in density or white spots △: There is unevenness in density or white spots, but there is no problem in practical use ×: There is unevenness in shade or white spots and cannot be used

(9) Evaluation of Printing Durability It is represented by the number of sheets that can be printed before the film is damaged by a printing machine. 5000 or more were rated as ⊚, 1000 or more were rated as ◯, and there was no practical problem, and less than 1000 were rated as x.

(10) Evaluation of transportability (curl) The prepared stencil paper was treated for 1 week in a thermo-hygrostat at 50 ° C. and a humidity of 90% RH, and then the paper was tested for conveyance using a printing machine. The following criteria evaluated.

◯: Good curl, but good conveyance Δ: Good curl, but practically good ×: curl is large, and conveyance troubles frequently occur

[0065]

【Example】

Example 1 Using a polyester having a dicarboxylic acid component of 2,6-naphthalenedicarboxylic acid dimethyl and a glycol component of ethylene glycol / 1,6-hexanediol (molar ratio: 60/40) as a main component polyester, according to a conventional method. After polymerization, 0.5 wt% of particles having an average particle diameter of 1.5 μm were contained as contained silica particles to obtain a polyester having an intrinsic viscosity of 0.75.

The obtained polyester was treated in boiling water for 3 hours to crystallize the surface, and then vacuum dried at 125 ° C. for 24 hours. After that, it was supplied to an extruder and melted at 240 ° C., and was sheet-shaped from a T-shaped die by an electrostatic application method to be closely cooled and solidified on a casting drum at 25 ° C. to obtain an unstretched film. Next, the unstretched film was heated to 85 ° C. and stretched 3.5 times in the longitudinal direction. Then, it was heated to 90 ° C., stretched 3.7 times in the width direction, heat-treated at 100 ° C. for 5 seconds, and cooled to obtain a 2.5 μm biaxially stretched film. The intrinsic viscosity of the film was 0.70. A wax-based release agent was applied to one side of the film at the inlet of the stenter with a bar coater at a weight after drying of 0.1 g / m ² .

A heat-sensitive stencil printing base paper was prepared by laminating the obtained film on the side not coated with the release agent with vinyl acetate as an adhesive and a natural fiber made from Manila hemp as a raw material and a Japanese paper having a fiber basis weight of 10 g / m ^2. Was produced. The amount of adhesive applied was 1 g / m ² . Perforation test based on the method described above,
A printing test, printing durability and transportability evaluation were carried out, and the results are shown in Table 1 together with the characteristics of the film.

Comparative Example 1 As the main component polyester, the dicarboxylic acid component was dimethyl terephthalate / dimethyl isophthalate (molar ratio: 70/30), and the glycol component was ethylene glycol, and was polymerized by a conventional method and contained. As silica particles, 0.5% by weight of particles having an average particle diameter of 1.5 μm was contained to obtain a polyester having an intrinsic viscosity of 0.76.

The obtained polyester was treated in boiling water for 3 hours to crystallize the surface, and then vacuum dried at 125 ° C. for 24 hours. After that, it was supplied to an extruder and melted at 280 ° C., and was sheet-shaped from a T-shaped die by an electrostatic application method to be closely cooled and solidified on a casting drum at 25 ° C. to obtain an unstretched film. Next, the unstretched film was heated to 90 ° C. and stretched 3.5 times in the longitudinal direction. Then, it was heated to 95 ° C., stretched 4.0 times in the width direction, heat-treated at 100 ° C. for 5 seconds, and cooled to obtain a 2.5 μm biaxially stretched film. The intrinsic viscosity of the film was 0.72. A wax-based release agent was applied to one side of the film at the inlet of the stenter with a bar coater at a weight after drying of 0.1 g / m ² .

A heat-sensitive stencil printing base paper was prepared by laminating the obtained film on the side not coated with the release agent with vinyl acetate as an adhesive, and with 100% natural fiber of Manila hemp as a raw material and Japanese paper having a fiber basis weight of 10 g / m ^2. Was produced. The amount of adhesive applied was 1 g / m ² . Perforation test based on the method described above,
A printing test, printing durability and transportability evaluation were carried out, and the results are shown in Table 1 together with the characteristics of the film.

Example 2 Polymerization was carried out by a conventional method using a polyester having a dicarboxylic acid component of 2,6-naphthalenedicarboxylic acid dimethyl as a main component and a glycol component of ethylene glycol / diethylene glycol (molar ratio: 60/40). ,
Particles having an average particle size of 1.5 μm were used as the contained silica particles.
5% by weight was included to obtain a polyester having an intrinsic viscosity of 0.75.

The obtained polyester was treated in boiling water for 3 hours to crystallize the surface, and then vacuum dried at 125 ° C. for 24 hours. After that, it was supplied to an extruder and melted at 240 ° C., and was sheet-shaped from a T-shaped die by an electrostatic application method to be closely cooled and solidified on a casting drum at 25 ° C. to obtain an unstretched film. Next, the unstretched film was heated to 85 ° C. and stretched 3.5 times in the longitudinal direction. Then, it was heated to 90 ° C., stretched 3.7 times in the width direction, heat-treated at 100 ° C. for 5 seconds, and cooled to obtain a 2.5 μm biaxially stretched film. The intrinsic viscosity of the film was 0.70. Others were the same as in Example 1 to obtain a heat-sensitive stencil printing base paper.
A perforation test, a printing test, printing durability and transportability were evaluated based on the methods described above, and the results are shown in Table 1 together with the characteristics of the film.

Example 3 As the main component polyester, the dicarboxylic acid component was dimethyl terephthalate and the glycol component was ethylene glycol / 1,6-hexanediol (molar ratio: 65/3
5) was polymerized by a conventional method to contain 0.5% by weight of particles having an average particle diameter of 1.5 μm as contained silica particles to obtain a polyester having an intrinsic viscosity of 0.78.

The obtained polyester was treated in boiling water for 3 hours to crystallize the surface, and then vacuum dried at 125 ° C. for 24 hours. After that, it was supplied to an extruder and melted at 240 ° C., and was sheet-shaped from a T-shaped die by an electrostatic application method to be closely cooled and solidified on a casting drum at 25 ° C. to obtain an unstretched film. Next, the unstretched film was heated to 60 ° C. and stretched 3.5 times in the longitudinal direction. Then, it was heated to 70 ° C., stretched 3.7 times in the width direction, heat-treated at 100 ° C. for 5 seconds, and cooled to obtain a 2.5 μm biaxially stretched film. The intrinsic viscosity of the film was 0.71. Others were the same as in Example 1 to obtain a heat-sensitive stencil printing base paper.
A perforation test, a printing test, printing durability and transportability were evaluated based on the methods described above, and the results are shown in Table 1 together with the characteristics of the film.

Example 4 As the main component polyester, the dicarboxylic acid component was 2,6-naphthalenedicarboxylic acid dimethyl / dimethyl isophthalate (molar ratio: 60/40) and the glycol component was 1,6-hexanediol. Polymerization was carried out by a conventional method, and 0.5% by weight of particles having an average particle size of 1.5 μm was contained as contained silica particles to obtain polyester having an intrinsic viscosity of 0.84.

The polyester obtained was treated in boiling water for 3 hours to crystallize the surface, and then vacuum dried at 125 ° C. for 24 hours. After that, it is supplied to an extruder and melted at 240 ° C., and a contacting method using a surface tension of water in a sheet shape from a T-type die and an electrostatic application method are used in combination to cool and solidify on a casting drum at 25 ° C. The unstretched film was obtained. Next, the unstretched film was heated to 75 ° C. and stretched 2.5 times in the longitudinal direction. Then, it was heated to 90 ° C., stretched 3.0 times in the width direction, heat-treated at 100 ° C. for 5 seconds, and cooled to obtain a 2.5 μm biaxially stretched film. This film was often torn during the production of the film, and the production yield was lowered. The intrinsic viscosity of the film was 0.75. Others were the same as in Example 1 to obtain a heat-sensitive stencil printing base paper. A perforation test, a printing test, printing durability and transportability were evaluated based on the methods described above, and the results are shown in Table 1 together with the characteristics of the film.

Comparative Example 2 Polyester as a main component was polymerized by a conventional method using a dicarboxylic acid component of dimethyl terephthalate and a glycol component of 1,6-hexanediol, and contained silica particles had an average particle diameter of 1.5 μm. 0.5% by weight of particles
A polyester having an intrinsic viscosity of 0.88 was obtained.

The obtained polyester was vacuum dried at 125 ° C. for 24 hours. After that, it is supplied to an extruder and melted at 200 ° C., and a sheet-shaped T-shaped die is used to adhere and cool and solidify on a casting drum at a temperature of 25 ° C. by a combination of an adhesion method using surface tension of water and an electrostatic application method. An unstretched film was obtained. Next, the unstretched film was heated to 60 ° C. and stretched 3.5 times in the longitudinal direction. Then, the film was heated to 80 ° C. and stretched 3.7 times in the width direction, heat treated at 100 ° C. for 5 seconds, and cooled to obtain a 2.5 μm biaxially stretched film. The intrinsic viscosity of the film was 0.80. Others were the same as in Example 1 to obtain a heat-sensitive stencil printing base paper. A perforation test, a printing test, printing durability and transportability were evaluated based on the methods described above, and the results are shown in Table 1 together with the characteristics of the film.

Comparative Example 3 As the main component polyester, the dicarboxylic acid component was dimethyl terephthalate / dimethyl adipate (molar ratio: 7
0/30), a polymer having a glycol component of ethylene glycol is polymerized by a conventional method, and 0.5 wt% of particles having an average particle size of 1.5 μm are contained as contained silica particles to obtain a polyester having an intrinsic viscosity of 0.75. Obtained.

The obtained polyester was treated in boiling water for 3 hours to crystallize the surface, and then vacuum dried at 125 ° C. for 24 hours. After that, it was supplied to an extruder and melted at 240 ° C., and was sheet-shaped from a T-shaped die by an electrostatic application method to be closely cooled and solidified on a casting drum at 25 ° C. to obtain an unstretched film. Next, the unstretched film was heated to 70 ° C. and stretched 3.5 times in the longitudinal direction. Then, the film was heated to 75 ° C., stretched 3.7 times in the width direction, heat-treated at 100 ° C. for 5 seconds, and cooled to obtain a 2.5 μm biaxially stretched film. The intrinsic viscosity of the film was 0.72. Others were the same as in Example 1 to obtain a heat-sensitive stencil printing base paper.
A perforation test, a printing test, printing durability and transportability were evaluated based on the methods described above, and the results are shown in Table 1 together with the characteristics of the film.

Examples 5 and 6 Film thicknesses of 0.4 μm (Example 5),
A heat-sensitive stencil printing base paper was obtained in the same manner as in Example 1 except that the thickness was changed to 4.2 μm (Example 6). Based on the method described above, perforation test, printing test and evaluation of printing durability are carried out,
The results are shown in Table 2 together with the properties of the film. Further, the film of Example 5 was often torn during the film production, and the production yield was lowered.

Example 7 As the main component polyester, 75 parts by weight of the polyester of Example 4 and 25 parts by weight of the polyester of Comparative Example 1 were used.
After vacuum-drying parts by weight at 125 ° C for 24 hours, dry blending, supplying to an extruder, melting at 280 ° C, and closely cooling and solidifying on a casting drum at 25 ° C by a static electricity application method into a sheet from a T-type die. The unstretched film was obtained. Next, the unstretched film was heated to 90 ° C. and stretched 3.2 times in the longitudinal direction. Next, after heating to 95 ° C. and stretching 3.5 times in the width direction, heat treatment is performed at 100 ° C. for 5 seconds,
After cooling, a 2.5 μm biaxially stretched film was obtained. The intrinsic viscosity of the film was 0.73. Others are Example 1.
In the same manner as in the above, a heat-sensitive stencil sheet was obtained. The punching test, the printing test and the evaluation of printing durability were carried out based on the above-mentioned methods, and the results are shown in Table 2 together with the characteristics of the film.

Example 8 The polyester of Example 4 was used in an amount of 60% by weight, and the polyester of Comparative Example 1 was used.
A heat-sensitive stencil printing base paper was obtained in the same manner as in Example 7 except that 40% by weight of the polyester was added. The properties of the film obtained as a result of the punching test, the printing test and the evaluation of the printing durability based on the method described above are shown in Table 2.

Example 9 The polyester of Example 1 was vacuum-dried at 125 ° C. for 24 hours as the main component polyester, and after 75 parts by weight, ethylene having a melt index of 6 g / 10 minutes and an ethylene content of 5% by weight was used. 25 parts by weight of a propylene copolymer are dry blended, supplied to an extruder and melted at 270 ° C., and a sheet is formed from a T-shaped die by an electrostatic application method at 25 ° C.
The film was closely cooled and solidified on the casting drum of 1 to obtain an unstretched film. Next, the unstretched film was heated to 90 ° C. and stretched 3.2 times in the longitudinal direction. Then, it was heated to 95 ° C., stretched 4.0 times in the width direction, heat-treated at 100 ° C. for 5 seconds, and cooled to obtain a 2.5 μm biaxially stretched film. Others were the same as in Example 1 to obtain a heat-sensitive stencil printing base paper. The punching test, the printing test and the evaluation of printing durability were carried out based on the above-mentioned methods, and the results are shown in Table 2 together with the characteristics of the film.

Comparative Example 4 The polyester of Comparative Example 2 was used as the main component polyester, and the weight ratio to the polyester of Comparative Example 1 was 60: 4.
A heat-sensitive stencil printing base paper was obtained in the same manner as in Example 1 except that dry blending was carried out at 0. The punching test, the printing test and the evaluation of printing durability were carried out based on the above-mentioned methods, and the results are shown in Table 2 together with the characteristics of the film.

Comparative Example 5 As the main component polyester, 40 parts by weight of the polyester of Example 4 and 60 parts by weight of the polyester of Comparative Example 1 were used.
After vacuum-drying parts by weight at 125 ° C for 24 hours, dry blending, supplying to an extruder, melting at 280 ° C, and closely cooling and solidifying on a casting drum at 25 ° C by a static electricity application method into a sheet from a T-type die. The unstretched film was obtained. Next, the unstretched film was heated to 90 ° C. and stretched 3.2 times in the longitudinal direction. Next, after heating to 95 ° C. and stretching 3.5 times in the width direction, heat treatment is performed at 100 ° C. for 5 seconds,
After cooling, a 2.5 μm biaxially stretched film was obtained. Others were the same as in Example 1 to obtain a heat-sensitive stencil printing base paper. The punching test, the printing test and the evaluation of printing durability were carried out based on the above-mentioned methods, and the results are shown in Table 2 together with the characteristics of the film.

[0087]

[Table 1]

[Table 2]

[0088]

INDUSTRIAL APPLICABILITY According to the present invention, the perforation property is good even at low energy, and the perforation diameter corresponding to the change in the energy level is provided to provide excellent gradation, and the printing durability and the transportability are excellent. It was possible to provide a film for base paper for heat-sensitive stencil printing.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location B29L 7:00 9:00

Claims (3)

[Claims] 1. A melting point (Tm) of 200 ° C. or lower, a glass transition point (Tg) of 50 ° C. or higher, and a temperature rising crystallization temperature (Tcc).
Difference between the glass transition temperature and the glass transition point (Tg) (ΔTcg: Tcc
A film for heat-sensitive stencil printing base paper, which is obtained by biaxially stretching a resin composition containing polyester as a main component having a −Tg) of 100 ° C. or less. 2. The main component polyester is 70% by weight.
The film for heat-sensitive stencil printing base paper according to claim 1, comprising the resin composition as described above. 3. The melting point (Tm) of the resin composition is 200 ° C. or lower, the glass transition point (Tg) is 50 ° C. or higher, and the temperature difference (Δ) between the temperature rising crystallization temperature (Tcc) and the glass transition point (Tg). T
cg: Tcc-Tg) is 100 [deg.] C. or less, The film for heat-sensitive stencil printing base paper according to claim 1 or 2, characterized in that: