JPH0645272B2 - High-sensitivity heat-sensitive platemaking paper and method for producing - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel high-sensitivity heat-sensitive plate-making base paper and a method for producing the same. More specifically, the present invention is
The present invention relates to a stencil sheet that exhibits excellent heat resistance and dimensional stability when punched by heat, and that provides a high-sensitivity and high-resolution stencil sheet, and a method for efficiently producing the stencil sheet without impairing the quality. .

2. Description of the Related Art In recent years, a technique has been developed and put into practical use in which a base paper is perforated and plate-formed by means of light, thermal head, discharge / current recording, and the like, and printed as a plate. In addition, new plate making methods such as LED arrays and laser heads are also being studied.

As a method of making an original plate used for such printing, conventionally, for example, an original showing characters and images with ink or toner that absorbs light rays is strongly pressed against the film surface of the original paper, and infrared irradiation or a xenon lamp is used. A method of making a character and an image portion of the original document generate heat by using a perforating means in a high energy region such as a flash of light, melting the film by transmitting the heat to the film surface, and making a plate by making holes. It has been known.

As the base paper for plate making used at this time, conventionally, thin paper,
It is stretched on a support such as gauze (mesh-shaped one) using a very expensive high-precision tenter, and at the same time, it is sufficiently heat-treated in the rear part of the tenter to be crystallized (crystallinity 45).
It is known that a single polyethylene terephthalate film having a thickness of about 2 μm is obtained, and then laminated with an adhesive in another step.

However, this laminate has sufficient heat resistance and is good in the dimension stability method, but when laminating on the support with an adhesive, unevenness of the support appears on the film surface by pressing. If the film is adhered as it is, the microscopic smoothness of the film surface is impaired, and due to the unevenness of the film due to thinness and uneven adhesion of the adhesive, scratches, wrinkles, sagging, and distortion (uneven tension) It is unavoidable that cuts will occur. Moreover, in order to laminate the polyethylene terephthalate film on the support, it is done with great care while stretching, but even with this method, it is difficult to uniformly laminate, and it is sufficiently satisfactory. The current situation is that no high quality base paper has been obtained.

When a plate is made using such a poor quality base paper, a curl phenomenon or peeling at the bonding surface occurs, resulting in sensitivity or
This causes an unfavorable situation such that the resolution is significantly reduced locally. Such a problem is not so important when using the punching means in the high energy region, but becomes extremely important when using the punching means in the low energy region.

By the way, recently, a minute heat generating element (eg, 10 to 16 dots / dot) that is widely used in various printers, word processors, facsimiles, etc., which are in the direction of digitization.
mm) has a miniaturization, high speed,
Researches on energy saving have been especially advanced.Therefore, when making a plate by using such a thermal head, a plate making base paper showing particularly high sensitivity and high resolution and having uniform quality is required. It

Hitherto, as a method for producing such a base paper, there has been proposed a method in which, for example, a thin single-layer film is used, and the film is laminated on a support while being brought into close contact with a mirror surface roll. (Sho 60-89396 gazette), such a method requires careful handling of the film, requires complicated operation, requires expensive laminating equipment, and a clean environment. There are problems such as having to consider measures against electricity. Also, if the film is made of a material that easily tears or has a low waist (elastic modulus), or if it is extremely thin with a thickness of 2 μm or less, various troubles occur and a base paper of sufficiently satisfactory quality is produced. I couldn't do that.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention overcomes the drawbacks of the conventional heat-sensitive platemaking paper, has a smooth surface, and causes quality defects such as scratches, wrinkles, sagging, distortion, floating, and breaks. The purpose of the present invention is to provide a base paper which is free from heat and can be subjected to heat-sensitive plate making with high sensitivity and high resolution.

Means for Solving the Problems The inventors of the present invention have conducted various studies on a novel base plate for heat-sensitive plate-making, and as a result, a functional layer having specific physical properties necessary for plate-making and printing is formed into a predetermined release layer. It was found that the object can be achieved by stacking on both surfaces and further providing a functional layer on the outermost layer thereof to provide a plate making support layer, and based on this finding, the present invention was accomplished. Ivy.

That is, the present invention, the release layer (P) on one side or both sides of the multilayer film laminated with the functional layer (M) by co-extrusion and co-stretching on both sides, the plate-making support layer in contact with the functional layer (S) In the multilayer film structure provided with, each functional layer (M) has a tensile elastic modulus of at least 75 kg / mm ² and a heat shrinkage ratio of 60 to 1
30 to 90% within the range of 70 ℃, heat shrinkage stress value of 60 to 150
A thickness of 0, which has the property of showing 100 to 1200 g / mm ² in the range of 0 ° C.
The release layer (P) is composed of a thermoplastic resin layer having a thickness of 5 to 18 μm. The release layer (P) contains 0.2 to 5% by weight of a release agent and is an ethylene resin having a Vicat softening point of 120 ° C. or less and a crystallinity of 60% or less. 3 ~
It is intended to provide a high-sensitivity heat-sensitive platemaking base paper which is characterized by comprising a resin layer having a thickness of 100 μm different from the functional layer.

Further, such a high-sensitivity heat-sensitive plate making paper contains 0.2 to 5% by weight of a predetermined release agent and has a Vicat softening point of 120 ° C.
Hereinafter, by co-extruding the thermoplastic resin for forming the release layer and the thermoplastic resin for forming the functional layer, which are made of a resin different from the resin for forming the functional layer, which is an ethylene-based resin having a crystallinity of 60% or less, A multi-layer film having a functional layer having a thickness of 0.5 to 18 μm laminated on both sides of a release layer having a thickness of 3 to 100 μm, and then contacting the functional layer on one or both sides of the multi-layer film to form a support layer for plate making. Can be manufactured by stacking.

The functional layer in the heat-sensitive plate-making base paper of the present invention is a resin layer portion for forming a plate necessary to bring out desired characters, patterns, etc. on a printing material in relation to printing. Is composed of an amorphous or low crystalline thermoplastic resin as a material. It should be noted that even a crystalline thermoplastic resin can be used as long as it can suppress the crystallinity to a low crystallinity of 30% or less depending on processing conditions. This is preferably 20% or less, more preferably 10% or less.

As the thermoplastic resin, for example, a copolymer polyester resin, a polyamide resin, an ethylene-vinyl alcohol copolymer, a polycarbonate resin, a copolymer polystyrene resin, an acrylic resin, a vinyl chloride resin, a vinylidene chloride copolymer Examples thereof include resins, and these resins may be used alone or in combination of two or more kinds (as a mixture or in a multilayer form).

The above-mentioned copolymerized polyester resin is one in which one or both of the dicarboxylic acid component and the diol component constituting the polyester are composed of two or more different components. When different dicarboxylic acid components are used, Include terephthalic acid and other dicarboxylic acids, for example, aromatic dicarboxylic acids such as isophthalic acid and phthalic acid, aromatic dicarboxylic acids having a substituent on the aromatic ring that does not contribute to the esterification reaction, succinic acid, adipic acid, etc. Combinations of aliphatic dicarboxylic acids are used, and when different diol components are used, for example ethylene glycol, propylene glycol, 1,4-butanediol, 1,5
-Pentanediol, 1,6-hexanediol, neopentyl glycol, polyethylene glycol, polytetramethylene glycol, cyclohexanedimethanol and the like are used in combination of two or more kinds.
Preferred copolymerized polyester resins include, for example, ethylene glycol as a diol component and 1,4
40% by mole or less of cyclohexanedimethanol, preferably 20 to 40% by mole, more preferably 25 to 36
This is a product obtained by polycondensing terephthalic acid with a polymer containing mol%. Among them, the crystallinity of the material which is sufficiently annealed as a raw material to be in an equilibrium state is 30%
The following can be mentioned. Preferably 20%
It is more preferably 10% or less, particularly preferably substantially amorphous.

As such a compound, for example, a compound containing terephthalic acid as a main component as a dicarboxylic acid component and a mixture of about 70 mol% of ethylene glycol and about 30 mol% of 1,4-cyclohexanedimethanol as a diol component is used. Some are polymerized.

Further, as the polyamide resin, for example, nylon-
6, 66, 6-10, 11, 12 and copolymer nylon 6
-66, 6-66-610, 6-66-612 and the like can be mentioned, but of these, a copolymer type is preferable. In addition to these, terephthalic acid, isophthalic acid,
It is also possible to use an aromatic dicarboxylic acid such as phthalic acid or a small amount of an aromatic dicarboxylic acid having a substituent on the aromatic ring that does not contribute to the polymerization reaction.

Among such copolymers, those obtained by copolymerizing the aromatic dicarboxylic acid are preferable because they have a rigid portion in the molecular structure (effective for appropriately improving the glass transition point), and also branched. A copolymer of a hydrocarbon component having a large amount or a component having a saturated cyclo ring or a polar group is preferable because it has an effect of lowering the crystallinity and similarly improving the elastic modulus. The crystallinity is the same as that of the polyester. The content ratio of these copolymerization components is 3
It is 0 mol% or less, preferably 20 mol% or less. However, it goes without saying that these are selected so as to simultaneously satisfy the properties of the film.

The ethylene-vinyl alcohol copolymer has an ethylene unit content of 20 to 50 mol%, preferably 30.
Those in the range of to 45 mol% are preferable. A composition obtained by modifying or mixing the copolymer with 40% by weight or less of at least one resin selected from nylon resins, polyester resins, and ionomer resins can also be used. It goes without saying that the film is selected so as to satisfy the characteristics of the film.

Furthermore, as the polycarbonate-based resin, it is preferable to use a monomer that lowers the softening point as compared with conventional resins, or a copolymer of the monomers. Also, a mixture of 5 to 40% by weight of another polymer capable of being formed into a film can be used. On the other hand, examples of the copolymerized polyester resin include those using acrylonitrile, acrylic acid ester, diene monomer, etc. as a copolymerization component. Among them, those obtained by copolymerizing acrylic acid ester. Is preferred.

Further, among these, preferred are amorphous ones,
In particular, a copolyester resin is preferable in terms of sensitivity, strength, printing durability, solvent resistance and the like.

These thermoplastic resins may include various additive components, such as antioxidants, heat stabilizers, plasticizers, auxiliaries, dyes, light absorbing substances, and specific heats, as long as they do not impair the film properties. A small filler, a heat conductive filler or the like can be added.

Among the above-mentioned additional components, the one to which the light absorbing substance is added,
When making a plate using a semiconductor laser, LED array, etc., it exhibits unprecedented excellent effects and has excellent perforation characteristics.

Furthermore, these thermoplastic resins constituting the functional layer are
The Bicatus softening point measured according to ASTM D-1525 (load 1 kg, temperature rising rate 2 ° C / min) is 40 to 150 ° C, preferably 50
A temperature in the range of to 130 ° C, more preferably 60 to 120 ° C, is suitable when utilizing a high level of perforation performance.

Such a thermoplastic resin film can be used not only as a base paper for heat-sensitive plate making according to the present invention, but also as a material for a base paper for recording information, recording element discs, sheets, tapes and the like.

The functional layer of the present invention needs to have a tensile elastic modulus of at least 75 kg / mm ² , preferably 100 kg / mm ² or more, more preferably 125 kg / mm ² or more. If the tensile modulus of elasticity is less than 75 kg / mm ² , the so-called stiffness of the film becomes weak and the workability of the obtained base paper is remarkably deteriorated. For example, when the functional layer and the release layer are peeled off, elongation or breakage may occur. There are many troubles such as the occurrence of deformation, the deformation of the plate during pressing, and the expansion and damage when used for printing.

This tensile elastic modulus was measured by a method according to ASTM D882-67, and the stress at 2% elongation was converted into 100% and displayed.

Also, this functional layer is 100-1200g /
It is necessary to have a heat shrinkage stress value of mm ² , preferably 150 to 1000 g / mm ² .

This heat shrinkage stress value is obtained by cutting the film forming the functional layer into strips with a width of 10 mm, setting it in a chuck with a strain gauge at 50 mm between the chucks and loosening it at each temperature. It was determined by immersing it in a heated silicone oil and detecting the generated stress. If the temperature of the silicone oil is 100 ° C or lower, the value after 10 seconds after dipping is used, and if it exceeds 100 ° C, the value after 5 seconds after dipping is adopted. In the case of a biaxially stretched film, the average value in the horizontal and vertical directions was adopted (hereinafter the same display method). The film is preferably biaxially stretched.
Further, even if a part of the shrinkage stress value at each temperature is included in the above range, it is within the range of the present invention. The shrinkage stress value in the above range needs to be expressed within the range of 60 to 150 ° C, preferably within the range of 60 to 140 ° C, and more preferably within the range of 70 to 130 ° C. This heat shrinkage stress value is 75 g / mm ²
The above is a necessary basic characteristic for effective occurrence of perforation, and a value lower than this makes it difficult to effectively perforate, for example, in the thermal head method, and exceeds 1200 g / mm ² . As a result, the apertures become too wide, the film is distorted, etc., and the resolution tends to decrease. Further, if the shrinkage stress value is expressed at a too low temperature, the dimensional stability of the film will be decreased and the resolution will be decreased due to the excessive opening of the film. Conversely, if it is expressed at a too high temperature, the perforation sensitivity will be decreased. This is not preferable because it causes a decrease.

Further, the heat shrinkage rate of this film must be 30 to 90%, preferably 40 to 80% within the range of 60 to 170 ° C. The heat shrinkage was determined by cutting out a 50 mm square film, placing it in a thermostatic chamber set to a predetermined temperature, and treating it for 10 minutes while allowing it to shrink freely. Expressed as a percentage.

It is necessary that the heat shrinkage ratio in the above range is exhibited at a set temperature of 60 to 170 ° C, more preferably 65 to 140 ° C. If this heat shrinkage ratio is less than 30%, it is difficult to effectively perforate, sensitivity tends to decrease, and dimensional stability and resolution tend to decrease. On the other hand, if it exceeds 90%, hole expansion or distortion may occur. There is a problem of reduced resolution and dimensional stability. Further, if the heat shrinkage rate is exhibited at a temperature that is too low, the dimensional stability is reduced, and if it is exhibited at a temperature that is too high, the perforation sensitivity is reduced, which is not preferable.

The thickness of the functional layer in the base paper of the present invention is 0.5 to 18 μm,
Preferably 1-18 μm, more preferably 2-18 μm
It is selected in the range of. If the thickness is less than 0.5 μm, it is difficult to handle and the strength is insufficient, breakage occurs during perforation, the resolution is lowered, and it is not practical, while if it exceeds 18 μm, perforation tends to be difficult, Workability is reduced. As an example of a preferable application, in the case of high-speed, especially low-energy-source plate making by the thermal head method, the thickness of the functional layer may be selected in the range of 1 to 8 μm, preferably 1 to 6 μm.

In addition, although not limited, in the case of perforating in the form of a self-supporting structure without using a porous support, the thickness is 5
-18 μm, particularly 5-12 μm, preferably 6 when punching by a thermal contact propagation method such as a thermal head.
It is preferable to select in the range of up to 12 μm.

Furthermore, when the film is mainly heated from the inside by a heat source such as a laser or an LED array, the thickness of the film is usually in the range of 1 to 18 μm. Among them, for example, in the case of using a support and making a plate at high speed and low energy, 1 to 6
It is good to select in the range of μm, preferably 1 to 3 μm,
When it is used in a self-supporting structure without using a support, it should be selected in the range of 5 to 18 μm, preferably 10 to 18 μm.

The functional layer in the present invention is usually a single layer, but may be composed of a plurality of layers made of different resins if desired.

Next, the release layer of the base paper for plate making of the present invention is necessary for imparting excellent properties during stretching. In addition to effectively transferring the additive to the functional layer, it protects the surface of the functional layer and also serves as a reinforcement when handling or processing the base paper, and after the lamination with the support is completed, Alternatively, it is removed immediately before plate making. Therefore, the release layer must be made of a material that can be easily released from the functional layer.

For this purpose, an ethylene-based polymer or copolymer having a Bicatt softening point of 120 ° C. or lower and a crystallinity (by the DSC method) of 60% or lower, or mainly of these, and other thermoplastic resin 50 wt. Mixtures containing up to% must be used.

Among these, preferred are ethylene-based copolymers as a main component, and a mixture of 5 to 50% by weight of ethylene-α olefin elastomer copolymer, and a polypropylene-based polymer per 100 parts by weight of this mixture. Examples thereof include a mixture containing 5 to 50 parts by weight of the coalesced product. As the ethylene-based copolymer, for example, ethylene-vinyl acetate copolymer containing 5 to 25% by weight of vinyl acetate unit, linear low density polyethylene, etc. are preferable.

Such a thermoplastic resin has good stretchability by itself, and also has the effect of significantly improving the stretchability of other layers adjacent to this resin layer, and the effect of necking stretch with other layers during stretching. Has the effect of preventing the occurrence. Furthermore, during co-stretching, there is an appropriate interlayer adhesion force, and there is no stretching strain due to the difference in the resins that make up each layer (strains that occur due to different stretching conditions in each single layer), and conversely as a whole. Optimum stretching conditions are broadened and synergistic effects such as stabilization are exhibited. As a result, not only the drawability (strength property etc.) of the composite layer is improved, but also the drawability of the thermoplastic resin film layer as the functional layer used in combination is significantly improved.

Further, the thermoplastic resin constituting the release layer has a crystallinity of 6 from the viewpoints of stretchability, bleeding property of additives, and mixing property.
It should be 0% or less. Further, if the temperature difference between the resin constituting the functional layer and the Bicatus softening point exceeds 150 ° C., the stretching conditions are too different from those of the functional layer, so it is advantageous to select the difference in the Bicatt softening point from the following. Is.

The release layer in the present invention needs to contain an appropriate release agent so that the release from the functional layer can be smoothly performed. Examples of such release agents include nonionic surfactants such as esters of fatty acids and polyhydric alcohols and polyoxyethylene alkyl ethers, higher alcohols, acid amides, waxes, fluorine-based and silicon-based polymers. Compounds and others conventionally used for this type of peeling are used. The amount of these release agents is usually based on the total weight of the thermoplastic resin forming the release layer,
It is selected within the range of 0.2 to 5% by weight. These release agents, after co-stretching, bleed to the surface of the release layer, facilitate the release of the functional layer and the release layer, and after laminating the support to the film layer, immediately by an online release treatment,
It is possible to wind up without breaking even under high-speed peeling conditions. The peel strength between the functional layer and the release layer is 1 cm after peeling both layers up and down at a speed of 200 mm / min using a tensile tester.
Expressed in terms of stress per width, it is usually 2 g / cm width or less, preferably 1 g / cm width or less. When imparting releasability, antistatic property and lubricity, and aiming for high-speed releasability, for example, a mixture containing oleic acid monoglyceride and polyglycerin monooleate in a weight ratio of 1: 1, Advantageously, it is contained in a proportion of 0.5 to 2.5% by weight, based on the total weight of the release layer.

In addition to the above-mentioned release agent, the release layer in the present invention may optionally contain various additives for improving the physical properties of the release layer, and transfer to a functional layer in contact therewith. It is also possible to include a transfer additive for changing its surface characteristics.

The thickness of the release layer of the present invention is 3 to 100 μm, preferably 5
˜50 μm, more preferably 5 to 20 μm. If this thickness is less than 3 μm, the peelability, stretchability, protection properties, transferability of additives, etc. will be low, while if it exceeds 100 μm, coextrudability will deteriorate and it is also not economically preferable.

The release layer is typically formed as a single layer, but can be formed as a composite layer if desired. In this case, a reinforcing layer made of a thermoplastic resin is used as a core, and a layer of a peelable resin containing a release agent is provided on both surfaces of the core. With such a composite layer, the reinforcing effect can be improved at any time. The thermoplastic resin constituting the reinforcing layer (P ₂ ) has a Bicatt softening point of 125 ° C. or higher, preferably 130
° C., more preferably at 135 ° C. or higher and a flexural modulus of 75 kg / mm ² or more, preferably suitably 85 kg / mm ² or more. As such a thermoplastic resin, for example, a propylene polymer is preferably used. This propylene-based polymer may be a homopolymer or a copolymer, and is a mixture containing another polymer such as polybutene-1 in a proportion of 40% by weight or less. You can buy it. Further, as the thermoplastic resin, polybutene-based polymers and copolymers, methylpentene-based polymers and copolymers, etc. can also be used.

In the case of using such a composite layer, it is necessary to make the adhesive strength between the peelable resin layer and the reinforcing layer larger than the adhesive strength between the peelable resin layer and the functional layer.

The thickness of the reinforcing layer is not particularly limited, but is usually selected in the range of 1 to 50 μm, preferably 2 to 30 μm.

As the support layer of the base paper for plate making of the present invention, either an ink-permeable porous sheet or a mount having irregularities on the surface is used depending on the purpose of use of the base paper. Examples of the former support layer include, for example, thin paper-like Japanese paper (weight per unit area of 4 to 15 g /
m ² ), a mesh screen woven fabric composed of synthetic fibers or natural fibers, and the like. The mesh screen woven fabric is preferably 50 to 500 mesh, preferably 70 to 300 mesh. is there. As for the latter,
A relatively thick functional layer, for example, having a thickness of about 6 to 18 μm, is used, and a mount having convenient irregularities at the time of punching is used. After plate making (perforating), the mount is peeled off, and a pattern is formed by discontinuous dot-shaped holes. As a specific support in the case where it is used for printing in a state in which a sheet is formed and carries information on it, the above-mentioned mount is mentioned.

As such a mount, for example, one having a regular arrangement of minute irregularities, that is, one having a convex portion is used, and the shape of the convex portion is an independent round shape, a square shape, an elliptical shape, a linear shape,
Or there are continuous mesh-shaped ones,
Some of these are arranged randomly. Preferably, they are regularly arranged, and the height of the convex portion is
It is usually 15 μm or more, preferably 25 μm or more, more preferably 30 μm or more. In the case of the independent shape, the size of each piece is usually 2.5 × 10 ^{-5 to} 1.44.
It is selected in the range of × 10 ^-2 mm ² . Further, the ratio of the effective area above the convex portion is about 1 to 35%. This convex portion is a portion to be laminated with the functional layer in a state of being easily peeled off. Further, the convex portion may be made of the same material as the base material, for example, a sheet, a film, etc., for example, an embossed one, or another material, for example, a film, a sheet, a paper,
The surface of the fiber or the like may be patterned by printing or a resist method.

These supports are laminated on the functional layer using an adhesive or by heat fusion or other means. The adhesive is not particularly limited, and conventionally known ones, for example, those dissolved in a solvent to be used, emulsion type latex type, hot melt type, powder type, reaction curing type by moisture, mixing, ultraviolet rays, etc. It can be appropriately selected and used according to the purpose from among those having a combination of these functions, for example, a hot-melt type with an emulsion and a curing type function added to the performance of the emulsion.

The amount of these adhesives used is usually 0.1 to
8 g / m ^2, preferably 0.2-5 g / m ^2, more preferably
It is selected in the range of 0.3 to 3 g / m ² . The laminating method is not particularly limited, and a commonly used method is appropriately selected and used according to the type of the adhesive to be used, and the desired thermoplastic resin film is used as the outermost layer of the laminated film. The support may be laminated. For coating the adhesive, for example, a coating roll having a doctor knife is used.

The cross-sectional structure of the base paper for plate making of the present invention includes S / M / P ₁ / MS S / M / P ₁ / M / S when the release layer is a single layer and S / M / P ₁ / MS S / M / P ₁ / M / S There are four types: M / P ₁ / P ₂ / P ₁ / MS / M / P ₁ / P ₂ / P ₁ / M / S.

However, M is a functional layer, (P ₁ ) is a release layer, (P ₂ ) is a reinforcing layer, S
Is a support layer.

According to the present invention, first, a multilayer film composed of a functional layer and a release layer is produced, and a support layer is laminated on one side or both sides of the multilayer film sequentially or simultaneously to obtain a desired plate-making base paper. You can

This multilayer film is formed by coextruding the above-mentioned thermoplastic resin for forming a functional layer and the above-mentioned thermoplastic resin for forming a peeling layer from a multi-nozzle and then co-stretching. The coextrusion and costretching at this time are not particularly limited, and a conventionally known method can be used, but under the condition that a sufficiently high orientation is contributed to each layer, the area stretching ratio is 4 to 49. It is preferable to uniaxially or biaxially co-stretch so as to double, and it is particularly preferable to simultaneously co-stretch in the biaxial direction so as to be longitudinally and laterally 2 to 7 times.

In the cross-sectional structure of this multilayer film, it is essential that at least one of the outermost layers is a functional layer, but the internal structure can be arbitrarily selected. For example _{M / P 1 / M M /} P 1 / P 2 / P 1 / M M / P 1 / M / P 1 M / P 1 / M / P 1 / M M / P 1 / M / P 1 / M / P ₁ M / P ₁ / M / P ₁ / M / P ₁ / M (where M, P ₁ and P ₂ have the same meanings as described above) In these multilayer films, there are two or more M layers. In this case, different types of M layers may be used, and the outermost M layer is provided with a peelable outer surface layer,
After stretching, the outer surface layer may be peeled off to expose the M layer.

The multilayer film thus obtained is then laminated with the required support layer, which support layer must be adhered to the outermost functional layer of the multilayer film. At this time, when a multi-layer film having two or more functional layers is used, a plurality of base papers can be obtained from one multi-layer film. For example, when the above-mentioned M / P ₁ / M / P ₁ / M type multi-layer film is used, two supports S are adhered to both surfaces thereof, and peeled between the intermediate M and P ₁ to obtain S. /
It is possible to obtain a base paper with two release layers of M / P ₁ and S / M / P ₁ / M.

The multilayer film has a release layer P ₁ adjacent to the functional layer M, such as M / P ₁ / M / P ₁ / M / P ₁ , and at least one outermost layer is the functional layer. If it has a multilayer structure of M, the support S is laminated on the outermost functional layer M, and then the laminate (base paper) composed of the support layer and the functional layer is peeled off, and the release layer P ₁ is removed, the same operation as described above is performed on the functional layer M whose surface is exposed, and the operation of peeling the laminate (base paper) composed of the support layer and the functional layer is sequentially repeated. The base paper can be obtained. In this case, the same operation may be sequentially repeated from the opposite side surface.

EFFECT OF THE INVENTION The heat-sensitive plate-making base paper obtained by the method of the present invention has a smooth film surface as compared with those obtained by the conventional method, and has no scratches, wrinkles, sagging, distortion, breakage, etc., and In addition to having high sensitivity and high resolution, the quality is uniform, and in particular, it can be suitably used for a plate making system for punching using a high speed and low energy source such as a thermal head.

Further, the method of the present invention (1) can evenly laminate a support even on a thin film of about 0.5 to 1 μm, which is difficult to laminate with a conventional method.
(2) Sliding and antistatic treatment of the film surface of the base paper,
It can be done automatically by bleeding from the release layer, (3) multiple base papers can be obtained from one laminated film, (4) a functional layer in which a support is laminated on both sides via the release layer The provided one is a product as it is and may be peeled off immediately before use, so that it is possible to use a base paper without curling, scratches, stains, etc., which is advantageous.
(5) The cost of the laminate is low, and (6) the unnecessary release layer can be recovered and reused.

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 As the functional layer (M layer), terephthalic acid and a mixed diol composed of 30 mol% of 1,4-cyclohexanedimethanol and 70 mol% of ethylene glycol were used, and the softening point of Bicatut was 82 ° C. and the density was 1.27 g. / Cm ³ , intrinsic viscosity 0.75
Of the substantially amorphous copolyester of (A) and the release layer (P ₁ layer) has a vinyl acetate unit content of 1
0% by weight, melt index 1.0, Vicat softening point 8
Ethylene-vinyl acetate copolymer 70 having a melting point of 1 ° C and a melting point of 95 ° C 70
Parts by weight, (B) density 0.88 g / cm ³ , melt index 0.4
4, 15 parts by weight of amorphous ethylene-α olefin polymer elastomer having a Bicatt softening point of 40 ° C., and (C) density of 0.90
g / cm ³ , melt florate 7, Bicatt softening point 138 ° C.,
Flexural modulus 110 kg / mm ² , melting point 143 ° C, and ethylene 4
15% by weight of random copolymerized crystalline polypropylene 15
2% by weight, based on the total weight of the composition, of a mixture containing, by weight, 2: 1 by weight of oleic acid monoglyceride and diglycerin monooleate in a mixture having a Bicatt softening point of 72 ° C. Using the composition contained therein, the reinforcing layer (P ₂ layer) is the same as the above-mentioned crystalline polypropylene, melted in an extruder, and the composition of each layer is M / P ₁ from the cyclic multilayer die. / P ₂ / P ₁ /
After being extruded so as to have M, it was rapidly cooled and solidified with a refrigerant to obtain a tube-shaped original fabric.

Next, this raw fabric is heated to 95 ° C., and in an atmosphere of 90 ° C., the stretching ratio is 5.0 times in the longitudinal direction and 5.0 times in the transverse direction.
After axial stretching, it was cooled with air at 20 ° C. and stretched into bubbles. Both ends of the obtained film were slit, and two films were wound into a roll by a winder. The thickness of each layer in this laminated film (M / P ₁ / P ₂ / P ₁ / M) was 2/8/2/8/2 μm.

On the other hand, as the support, Japanese paper consisting of 150 mesh polyester fibers (fiber diameter 45 μm) and Manila hemp fibers having a basis weight of 8.7 g / m ² was used, and an ethylene-vinyl acetate copolymer resin was dissolved in methanol as an adhesive. The support was laminated on both sides of the above-mentioned laminated film. At this time, the adhesive used was an equivalent amount of 3.5 g / m ^{2 in} terms of solid content.

Lamination can be carried out extremely smoothly, and it can be uniformly processed without causing wrinkles, scratches, and curling during drying. The obtained laminated body is easy to handle, has sufficient elasticity, and since the M layer surface is protected, no dust or scratches occur,
Moreover, the curl phenomenon did not occur at all.

This laminate can be easily peeled off before use.
It could be used as a sheet of base paper.

Only the M layer was peeled off and its properties were measured. Tensile breaking strength was 1.82 kg / mm ² , tensile breaking elongation was 110%, tensile elastic modulus was 220 kg / mm ² , and shrinkage stress was 430 g / mm ^2. (Peak value at 85 ° C.), and the heat shrinkage percentage was 78% at 80 ° C.

Also, peeling between the M layer and P ₁ layer is easy, and the peeling strength is 0.8g.
/ Cm width, at an appropriate level. After lamination,
Even when peeled at a speed of 100 m / min, it could be peeled smoothly. Furthermore, the adhesive strength between the P ₁ layer and the P ₂ layer was at a level at which separation was not possible.

On the other hand, the release agent not only provides a good release effect but also M
Providing adequate adhesion between the layers and the P ₁ layer, there was no occurrence of wrinkles or floating among the layers during stretching, handling or laminating. For comparison, when the same procedure was performed without using a release agent, the M layer broke and could not be removed smoothly, and in that case, static electricity was severely generated, dust was adhered, and sparks were generated. It was easily torn and wrinkled. By using a release agent, in addition to providing a stable release effect between layers and other effects described above, a sticking problem in a line type thermal head in a plate making machine (a film sticks to the thermal head and is torn or wrinkled). And the development in which the punched image is distorted) did not occur. In the conventional commercially available crystallized polyester film (2 μm), because of the high temperature required for perforation, etc., compared with the case where a special anti-stick agent is recoated, the product obtained by the present invention is This is advantageous because it is not necessary to coat an anti-stick agent. Furthermore, the peeled and removed P ₁ / P ₂ layer could be recovered and reused.

Next, when the M layer was set to 0.5 μm and carried out in the same manner, it was possible to easily stretch, and a base paper having an M layer as a functional layer having an ultrathin thickness that has never been considered before,
It was able to be manufactured smoothly without any wrinkles, scratches or tears. Further, even if the M layer has a thickness of 10 μm or 15 μm, it can be stretched more uniformly than the single film and can be laminated uniformly. In the case of stretching alone, if the thickness is 8 μm or less, flattening or significant uneven thickness occurs, and uniform stretching cannot be performed.

In the laminated body obtained by laminating the above-mentioned support, the base paper composed of the M layer and the support was peeled off, and a line type thermal head (16 dots / mm) and a serial type thermal head (24 dots / 24
Use Dotsu tomato theory scan display one), results platemaking test having conducted, both the low energy range, for example, to the serial type Max energy 35 mJ / mm ² of memory, Min energy 15 mJ / mm ² In the low energy region, and even at a high printing speed (moving speed of the thermal head: 13 cm / sec), perforation plate making was sufficiently possible (provided that the thickness was 0.5 to 6 μm).

Further, for comparison, the same test was carried out using a commercially available base paper having a crystallized (crystallinity of 45%) polyethylene terephthalate film having a thickness of 2 μm. The character of was unreadable, and the perforation was not sufficient even if the energy was set to Max, and the printed matter was faint and difficult to read.

Further, for comparison, when the M layer having a thickness of 2 μm was peeled off and laminated on the support, wrinkles were generated on the base paper, and the rolls at the time of lamination caused unevenness of the support to form a film having the thickness of 2 μm. As a result, the heat of the fine thermal head could not be transferred uniformly and effectively, and effective perforation was difficult, and the sensitivity was low.

Example 2 The same layers as in Example 1 were used as the M layer and the P ₁ layer, respectively, and the layer structure was M / P ₁ / M in the same manner as in Example 1.
When a laminated film having a thickness of 2/15/2 μm was prepared, the stretching was smooth, and no puncture or peeling between layers occurred. In addition, each property of the M layer was within the preferred range of the present invention.

Next, using a 200-mesh gauze as a support and a UV curing agent as an adhesive, the support was simultaneously laminated on both surfaces of the laminated film. The amount of the curing agent used at this time was 0.4 g / m ² . Lamination can be carried out smoothly, and a uniform raw material was obtained.

For comparison, when a commercially available polyethylene terephthalate film having a thickness of 2 μm was used and the support was laminated, wrinkles tended to occur, and stronger tension was applied in the length direction and the width direction to finally laminate. I was able to. However, wrinkles, uneven coating of the adhesive, breakage, and distortion occurred, and the uniformity was poor. Further, in this product, the irregularities of the support were transferred to the film surface, and at first it seemed to be flat, but the base paper curled and irregularities occurred later.

Next, the base paper consisting of the M layer and the support was peeled off from the base paper of the example, and a commercially available 24 dots (corresponding to about 8.1 dots / mm) matrix printing density was obtained for the base paper and the base paper of the comparative example. Using a personal word processor having a serial type thermal head, a plate making (piercing) test was performed at a printing speed of 20 characters / sec. As a result, in the case of the present example, it was possible to effectively perforate with Min perforation energy of 10 mJ / mm ² . On the other hand, in the comparative example, Ma
Even if the perforation energy of x was 30 mJ / mm ² , the perforation could not be effectively performed.

Then, using the resist method, the height of 40μ in the interval of 150 meshes.
m, a projection having a diameter of 20 μm and a base material having a thickness of 50
After creating a sheet-like pattern of μm, using this as a backing sheet, coating the UV curing agent on the convex part,
In addition, M / P ₁ / M (thickness 10
/ 8/10 μm) multi-layer films were stacked and cured to obtain an original fabric. Next, when the base paper consisting of the M layer and the backing paper was peeled off from this stock, the film surface was excellent in smoothness.

For comparison, an M layer having a thickness of 10 μm was peeled from the multi-layer film having an M / P ₁ / M structure, and the M layer was laminated on the above-mentioned mount and cured similarly to obtain a base paper. This product had unevenness and wrinkles, and the coating amount of the adhesive was uneven.

Next, a perforation test was performed on these base papers using the word processor (the base paper was peeled off after perforation). The base paper of the present invention showed sufficiently uniform perforation at a maximum energy level with high sensitivity. Also, the printed image had high resolution. On the other hand, the comparative one had insufficient perforation even at the same maximum energy level, and only a non-uniform image was obtained. Further, when observed under a microscope, the image on the base paper of the present invention had dot-shaped perforations formed with bridging made of a substantially uniform polymer,
The images on the base paper of the comparative example were insufficiently perforated where they should be perforated, or the bridging was broken and the holes were enlarged, resulting in insufficient perforation (a condition in which the sensitivity of the film was insufficient) as a whole. .

Further, even when printing about 1000 sheets at a printing speed of 100 sheets / min using a drum type automatic inking type automatic printing machine, the present invention does not cause character loss at all and has a high resolution. A high and clear print was obtained. On the other hand, in the case of the comparative example, although it was originally blurred and only insufficient printing was possible, there were still some characters missing and a hollow phenomenon occurred.

Example 3 Under the optimum conditions as in Example 1, except that an ethylene-vinyl alcohol copolymer containing 40 mol% of ethylene units was used as the resin constituting the M layer, the constitution of each layer was M / P ₁ / P ₂ / P ₁ / M and the thickness of each layer is 2 /
An 8/2/8/2 μm multilayer film was prepared. This M
When the layers were peeled off and the respective properties were examined, all were within the preferred range.

Then, the above-mentioned multi-layer film was processed in the same manner as in Example 1 to obtain 150
The mesh fabric was laminated (however, the UV curing method was used) to obtain a raw fabric. The handleability of this product was as good as in Example 1. Further, when a base paper consisting of the M layer and the support was peeled from the raw fabric and a perforation test was conducted,
Punching was possible effectively at an energy level of 30 mJ / mm ² of a personal word processor with a commercial printing density of 24 dots, and good results were obtained when a printing test was conducted.

In Example 1, the resin forming the M layer had an average particle size of 0.
M / P ₁ / P ₂ / P ₁ / in the same manner as in Example 1 except that 1% by weight of a carbon black of 03 μm was contained.
It has a layer structure of M, and the thickness of each layer is 2/8/2 /
An 8/2 μm multilayer film was prepared. The characteristics of the M layer film were all within the preferred ranges.

Then, the multilayer film was coated with 200
After a support made of mesh gauze was laminated to obtain an original fabric, the original paper comprising the M layer and the support was peeled from the original fabric. Lamination can be performed smoothly, and the M layer of the base paper had a uniform smooth surface.

A semiconductor laser (maximum output: 30 mW, wavelength: 780n) that is focused on a spot of 10 μm with a collimating lens on this base paper.
m) beam was irradiated for 1/100 seconds and a perforation test was conducted, and it was possible to perforate with an energy of 5 mW.
Using the XY plotter and the transmitter, the base paper was made into a plate and printed, and it was possible to perform fine printing with high resolution and high resolution.

For comparison, a base paper laminated with a polyethylene terephthalate film (thickness 2 μm) having a crystallinity of 47% containing 1% by weight of carbon black having an average particle diameter of 0.03 μm (thickness 2 μm) was used in the same manner as above. When a punching test was conducted, it was impossible to punch.

Claims (3)

[Claims] 1. A multi-layer film having a functional layer (M) laminated on both sides of a release layer (P) by co-extrusion and co-stretching,
In the multilayer film structure in which the plate-making support layer (S) is provided in contact with the functional layer, each functional layer (M) has a tensile elastic modulus of at least 75 kg / mm ² and a heat shrinkage rate of 60 to 170 ° C. Within the range of 30 to 90%, and the heat shrinkage stress value within the range of 60 to 150 ° C shows 100 to 1200 g / mm ²
m thermoplastic resin, the release layer (P) is a release agent 0.2-5
% Of ethylene resin having a Vicat softening point of 120 ° C. or less and a crystallinity of 60% or less, and is composed of a resin layer having a thickness of 3 to 100 μm different from the functional layer. Sensitivity heat-sensitive platemaking paper. 2. A peeling layer (P) comprising a reinforcing layer (P ₂ ) and a peeling agent laminated on both sides thereof, which is an ethylene resin having a Vicat softening point of 120 ° C. or lower and a crystallinity of 60% or lower. The high-sensitivity heat-sensitive platemaking base paper according to claim ₁ , which is composed of a resin layer (P ₁ ) different from the functional layer. 3. An ethylene-based resin containing 0.2 to 5% by weight of a release agent, having a Vicat softening point of 120 ° C. or less and a crystallinity of 60% or less, for forming a release layer made of a resin different from a resin for forming a functional layer. By co-extruding a thermoplastic resin and a thermoplastic resin for forming a functional layer, and then co-stretching, a multi-layer film in which a functional layer having a thickness of 0.5 to 18 μm is laminated on both sides of a release layer having a thickness of 3 to 100 μm A method for producing a high-sensitivity heat-sensitive plate making paper, which comprises forming and then laminating a support plate layer for plate making on one side or both sides of the multilayer film in contact with the functional layer.