JP2003094850A - Manufacturing method for original paper for thermal stencil printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing excellent original paper for thermal stencil printing which causes no problem of wrinkling, streaking, lifting or the like and besides is excellent also in the uniformity of thickness, smoothness and others, while using a porous substrate corresponding to a high image quality and having a small basis weight. SOLUTION: While the porous substrate P is carried by a laminating roll 2 of which the peripheral surface is non-adherent to an adhesive, a thermoplastic resin film F is laminated on the substrate. Then, a laminate L thus obtained is subjected to an inverting process wherein the laminate L is carried, while the surface thereof opposite to the side being in contact with the roll in the preceding process is brought into contact with the peripheral surfaces of carrying rolls 6 and 7, and wherein the direction of carriage is so inverted that angles θ3 and θ4 are in the range of 90-270 deg. respectively. After this process is conducted at one time at least, the adhesive G is dried.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a heat-sensitive stencil printing base paper used for heat-sensitive stencil printing.

[0002]

2. Description of the Related Art In recent years, a thermoplastic resin film (thermosensitive resin) that melts when heated and heat-shrinks to form through holes on a porous support formed by paper-making natural or synthetic fibers. Layers) are laminated and adhered to each other, and a thermosensitive stencil printing base paper is used. Among them, a thermoplastic resin film is made to correspond to an original image read by an image scanner, and a large number of through holes are formed by heat fusion using a thermal head. After making a stencil (master) by forming a, the so-called digital heat-sensitive stencil printing that performs printing corresponding to the above-mentioned original image on the surface of paper etc. using this stencil and ink, It was developed as an advanced form of stencil printing.

The respective units for performing these steps are arranged in a casing having a size similar to that of the electrostatic copying machine, and these steps are performed by the same simple operation as copying by the electrostatic copying machine. It is an automated system that can be performed gradually as a simple and simple printing device suitable for so-called short run printing of several to several thousand sheets, and at a lower cost and higher speed than copying by an electrostatic copying machine. It is becoming popular. A further important issue in the printing apparatus in the future is to achieve higher image quality, and therefore, the thermal head is being made finer and finer on the apparatus side.

Further, in order to prolong the life of the miniaturized and high-definition thermal head as described above, it is required to reduce the heating energy for forming the through holes more than ever before. As a heat-sensitive stencil printing base paper used in the above-mentioned apparatus, one that can form good through holes promptly with lower energy is becoming necessary. Therefore, in response to this, as a thermoplastic resin film, a film with a thickness of 3.0 μm or less, which is smaller than before, has a low melting point, and has a high heat shrinkage ratio at the time of heating and melting, is considered to be used. In addition, as a porous support, by reducing the fiber diameter or decreasing the fiber density,
The use of those whose basis weight has been reduced to 9.0 g / m ² or less is being studied.

[0005]

Generally, a heat-sensitive stencil printing base paper is obtained by continuously laminating and adhering a long thermoplastic resin film and a porous support through an adhesive applied to either of them. After that, it is manufactured by drying the adhesive. For example, in the manufacturing method of FIG. 4, first, a porous support P continuously supplied from a raw roll (not shown) as shown by a white arrow in the drawing is provided on the outer periphery of the porous support P.
Is removed from a wrinkle, a streak, etc. through a spiral roll 91 having a spiral groove for conveying while being pulled in the axial direction of the roll, and then supplied to a laminating roll 93.

On the other hand, a thermoplastic resin film F continuously supplied as shown by a black arrow in the drawing from an original roll (not shown) is passed between the gravure roll 94 and the back roll 95 and one surface thereof ( Adhesive G is applied to the lower surface (in the figure), and then spiral roll 9 similar to the above is applied.
After removing wrinkles, streaks and the like through 6, it is supplied to the laminating roll 93. Then, the laminating roll 93
The thermoplastic resin film F is laminated on the porous support P in the middle of transportation while being in contact with the peripheral surface of the laminate (lamination step),
Then, the laminate L is passed through spiral rolls 97, 98 as shown by solid arrows in the figure to remove wrinkles, stripes and the like, and then sent to a drying step (not shown) to dry, solidify or cure the adhesive to obtain heat sensitivity. A stencil sheet is manufactured.

In the above production method, when a conventional porous support having a basis weight of more than 9.0 g / m ² is used, thermoplasticity is applied while applying high tension in the laminating step. It is possible to stack resin films,
Almost no problems such as wrinkles and wrinkles or so-called plows in which air was introduced between the porous support and the thermoplastic resin film occurred. However, as described above, a rigid porous support having a basis weight of 9.0 g / m ² or less, which is intended to improve image quality, cannot apply strong tension, and the applied tension is not appropriate. Then, wrinkles and streaks are easily generated even through the spiral roll, and the thermoplastic resin film cannot be laminated neatly, which makes it difficult to adjust the tension.

Further, as described above, since the adhesive easily penetrates from the coated surface to the opposite surface in the porous support having a small basis weight,
Adhesive that has permeated adheres to the surface of the laminating roll and the like, and wrinkles, lines, and scratches are generated by varying the tension when the porous support separates from the roll, or the surface of the laminating roll once. There is also a problem that the adhesive adhered to and dried on the surface of the porous support is redeposited on the back surface of the porous support to impair the thickness uniformity and smoothness of the heat-sensitive stencil printing base paper.

In order to solve these problems, the diameter of the laminating roll used in the laminating step is regulated within a prescribed range, and the contact amount of the porous support with the laminating roll is regulated within a prescribed range. It has been proposed to use a spiral roll as a laminating roll (JP-A-10-203040). However, according to the studies by the inventors, the above problems still could not be surely prevented only by such a device in the laminating step.

An object of the present invention is to use a porous support having a small basis weight corresponding to high image quality, without causing problems such as wrinkles, streaks, and streaks, and having uniform thickness and smoothness. Another object of the present invention is to provide a method for producing a good base paper for heat-sensitive stencil printing which is excellent also in the above.

[0011]

In order to solve the above-mentioned problems, the inventors have reexamined each step of the continuous production method of the heat-sensitive stencil printing base paper. As a result, (1) after the laminating step, the laminated body before drying the adhesive is conveyed while the surface opposite to the side that was in contact with the roll in the previous step is in contact with the peripheral surface of the conveying roll. And set the transport direction to 9
When the reversing step of reversing in the range of 0 to 270 ° is performed at least once, even if wrinkles, lines, plows, etc. occur in the laminating step, they are eliminated in this reversing step.
(2) If the laminating roll used in the reversing step has at least its peripheral surface formed of a material that is non-adhesive to the adhesive, fluctuations in tension due to the adhesive that has permeated the porous support are prevented. It is possible to suppress the occurrence of wrinkles, lines, and streaks in the laminating process, and the uniformity of the thickness caused by the adhesion of the adhesive to the laminating roll and the re-adhesion to the porous support. The inventors have found that the deterioration of smoothness and smoothness can be suppressed, and completed the present invention.

That is, according to the method for producing a heat-sensitive stencil printing base paper of the present invention, a long thermoplastic resin film and a porous support are continuously laminated and adhered via an adhesive, and then the adhesive is dried. A method for producing a heat-sensitive stencil printing base paper, wherein the porous support is such that at least its peripheral surface is non-adhesive to the adhesive in a state where the adhesive surface with the thermoplastic resin film is on the outside. A thermoplastic resin film is laminated at a midway position while being conveyed while being in contact with the peripheral surface of the laminating roll formed of the material (laminating step), and then with respect to the laminated body laminated in this laminating step. Inversion step below Inversion step: The laminate is conveyed while the surface on the side opposite to the side in contact with the roll in the previous step is in contact with the peripheral surface of the conveyance roll, and the conveyance direction is 90 to 270 °. Invert by range The method is characterized in that the adhesive is dried at least once and then dried.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to FIGS. 1 (a) and 1 (b) showing an example of an embodiment thereof. As shown in these figures, in the manufacturing method of this example, first, the porous support P continuously supplied from the unillustrated original roll as shown by the white arrow in the figure First, after removing the wrinkles, streaks and the like through the spiral roll 1 having a spiral groove cut to convey the porous support P while pulling it in the axial direction of the roll, the porous support P is supplied to the laminating roll 2.

On the other hand, a thermoplastic resin film F continuously supplied as shown by a black arrow in the drawing from an original roll (not shown) is passed between the gravure roll 3 and the back roll 4 and one surface thereof ( Adhesive G on the bottom surface in the figure)
And then the same spiral rolls 5 and 5 as above.
After removing wrinkles, lines, etc., it is supplied to the laminating roll 2. Then, the thermoplastic resin film F is laminated on the porous support P that is being conveyed while being in contact with the peripheral surface of the laminating roll 2 (laminating step).

As the above-mentioned laminating roll 2, one having at least its peripheral surface formed of a material which is non-adhesive to an adhesive as described above is used. The reason is as described above. As such a laminating roll 2, for example, one having at least its peripheral surface formed of a polyethylene resin, a polypropylene resin, a fluorine resin, a polyamide resin, or the like is preferably used, and among them, a typical example of the fluorine resin is poly. Those formed of tetrafluoroethylene resin are particularly suitable for use because they are non-adhesive to the adhesive agent described later and have excellent abrasion resistance.

In the laminating step, as shown in FIG. 2B, the porosity of the porous support P is adjusted so that the bending angle θ _{1 in the} transport direction of the laminating roll 2 is in the range of ₁₀ to 180 °. While the support P is brought into contact with the peripheral surface of the laminating roll 2 and conveyed, the bending angle θ _{2 of the} thermoplastic resin film F in the conveying direction by the laminating roll ₂ is 5 to 90 ° at a midway position thereof. After laminating the thermoplastic resin film F so as to be in the range, the laminating roll 2, the spiral rolls 1 and 5 before and after the laminating roll 2, and the conveying roll 6 are arranged so as to send the laminated body L to the next step. preferable.

When the bending angles θ ₁ and θ ₂ are set in this way, there is an advantage that problems such as wrinkles, lines, and scratches can be more reliably prevented in the laminating process by the laminating roll 2. In addition, in order to more effectively prevent problems such as wrinkles, lines, and puffs in the stacking process, the bending angle θ ₁ is particularly 20 to 90 even within the above range.
It is preferably in the range of °. For the same reason, the bending angle θ ₂ is preferably within the above range, particularly within the range of 10 to 90 °.

Next, the laminated body L is conveyed while the surface on the side opposite to the side in contact with the roll in the previous laminating step, that is, the surface on the thermoplastic resin film F side is in contact with the peripheral surface of the conveying roll 6. And the reversal angle θ ₃ is 90 to
The first inversion step is performed by reversing so as to be in the range of 270 °. Then, next, the surface of the reversed laminated body L on the side opposite to the side in contact with the roll in the first reversing step, that is, the surface on the side of the porous support P is used as the peripheral surface of the transport roll 7. The sheet is conveyed while being in contact with it, and the conveying direction is reversed so that the reversal angle θ ₄ is in the range of 90 to 270 ° as described above, and the second reversing step is performed.

Then, after passing through the above-mentioned two reversing steps, the laminated body L is in a good laminated state in which wrinkles, lines, plows and the like generated in the laminating step are eliminated, and therefore, as shown by solid arrows in the figure. When the adhesive is dried, solidified or cured by passing through a spiral roll 8 to a drying process (not shown), the above wrinkles, lines and streaks are not generated, and the thickness is uniform and smooth. Good heat-sensitive stencil sheets are produced continuously.

In the above-described two reversing steps, the reversing angles θ ₃ and θ _{4 in} the conveying direction of the laminated body L are 90 to 270 °, respectively.
Is limited to the range of
This is because the above-described inversion step cannot obtain the effect of eliminating wrinkles, lines, plows, etc. of the laminated body L, and those having an inversion angle of more than 270 ° have a structure in which the laminated body L and rolls before and after being inverted are used. This is because the types are too close to each other, which makes maintenance difficult.

In order to more effectively eliminate the wrinkles, lines, and streaks of the laminated body L without causing maintenance problems, the reversal angles θ ₃ and θ ₄ are respectively in the above range. Among them, it is particularly preferably about 120 to 210 °. When the reversing step is performed twice or more as described above, the conveyance roll 6 used in the first reversing step is a roll having a function of conveying the laminate L while pulling the laminate L in the axial direction of the roll, that is, It is preferable to use the above-mentioned spiral roll or the like. By using such a spiral roll or the like to convey the laminate L while pulling the roll in the axial direction, wrinkles, lines,
It is possible to more surely eliminate the depression.

The spiral roll used for the transport roll 6 is a roll having spiral grooves S1 and S2, which are reversely rotated from the center in the axial direction to the left and right, are cut on the peripheral surface as shown in FIG. When the spiral roll S is rotated in the direction indicated by the solid line arrow in the drawing, the laminated body L that is brought into contact with the peripheral surface of the spiral roll S and is conveyed is pulled to the left and right in the axial direction of the roll.
The force indicated by the alternate long and short dash line in the figure is generated, and thereby wrinkles, lines, plows, etc. generated in the laminated body L are more reliably eliminated.
As the spiral rolls 1, 5 and 8, the same ones as described above are used.

The conveying roll 7 used in the final reversing step before sending the laminated body L to the next drying step, such as the second time, has a diameter of 5 to 30% of the width of the laminated body L. Preference is given to using large-diameter and smooth-surfaced transport rolls. When a transport roll having such a large diameter and a smooth surface is used, the tension is stable, and a uniform surface pressure can be applied to the laminate L for a relatively long time with a gentle curvature. It is possible to more reliably eliminate the wrinkles, lines, and streaks that have occurred.

In order to make the above effect more reliable, the diameter of the transport roll 7 is 10 to 10 times the width of the laminate L.
More preferably, it is about 25%. For the same reason as in the case of the laminating roll 2, a roll having at least its peripheral surface formed of a material that is non-adhesive to the adhesive, such as polytetrafluoroethylene resin, is used as the conveying roll 7. Preferably. Incidentally, in the present invention, the reversing step may be performed only once, as shown in FIG. 2, for example.

That is, at least the peripheral surface of the laminating roll 2 is made of a material that is non-adhesive to the adhesive.
According to the procedure described above, the steps up to the step of laminating the porous support P and the thermoplastic resin film F are performed in the same manner as in FIGS. 1 (a) and 1 (b) above (therefore, the same members are designated by the same reference numerals and their description is omitted). The laminated layered body L is conveyed while the surface on the side opposite to the side in contact with the roll in the previous laminating step, that is, the surface on the thermoplastic resin film F side is in contact with the peripheral surface of the conveying roll 10. Then, the conveyance direction is reversed so that the reversal angle θ ₅ is in the range of 90 to 270 °, and the reversing step is performed only once.

The reversal angle θ ₅ is limited to the above range for the same reason as above. Further, the bending angles θ ₁ and θ _{2 of} the porous support P and the thermoplastic resin film F by the laminating roll 2 in the laminating step are preferably set in the same range as above for the same reason as above. . Further, as the transport roll 10, the one-time reversal step corresponds to the final reversal step before being sent to the drying step, so that the diameter thereof is 5 to 30% of the width of the laminated body L. Then, a transport roll having a smooth surface is preferably used. The reason is as described above.

After that, by being inverted, wrinkles, lines,
Laminated body L in a good laminated state in which fluff and the like are eliminated
The drying step (not shown) as indicated by the solid line arrow in the figure.
And send the adhesive to dry, solidify or cure,
The base paper for heat-sensitive stencil printing that is free from the above-mentioned wrinkles, lines, lines, etc. and is excellent in uniformity of thickness and smoothness is continuously produced. Examples of the porous support P used in the production method of the present invention include natural fibers and chemical fibers such as rayon, vinylon, nylon and polyester, which may be used alone or in combination of two or more, by a wet or dry method. Examples include paper-made materials. Especially, the fiber diameter is 0.5
Porous support containing 5% or more of denier or less and having a basis weight of 9.0 g / m ² or less, a thickness of 34.0 μm or less, and a density of 0.26 g / m ³ or less as described above. The production method of the present invention is suitable for producing a heat-sensitive stencil printing base paper using the body 2.

The thermoplastic resin film laminated with the porous support P is formed of, for example, polyester, chlorinated polypropylene, vinylidene chloride-vinyl chloride copolymer, propylene-ethylene copolymer, polypropylene or the like. A thin film having a thickness of 3.0 μm or less is preferable. Examples of the adhesive G include vinyl acetate type, acrylic type, polyurethane type, rubber type, epoxy type, chlorinated polyolefin type, vinyl chloride type, vinylidene chloride,
A ternary or binary copolymer system of vinyl chloride and acrylonitrile, and solvent solution type, emulsion type, solventless type (melt solid type, one-component reaction curing type, two-component reaction curing type,
Various types of adhesives (including ultraviolet curing type) can be used.

The amount of the adhesive G applied to the thermoplastic resin film F by the gravure roll 3 is not particularly limited. However, in particular, as described above, a thin porous support P having a basis weight of 9.0 g / m ² or less, through which an adhesive can easily pass.
In the case of using, in order to suppress the occurrence of the above-mentioned problems due to the permeation of the adhesive as much as possible, and yet to firmly bond the porous support P and the thermoplastic resin film F without causing adhesive breakage. , The amount of the adhesive G applied is 0.1 to 0.
It is preferably set to about 5 g / m ² .

As a method of applying the adhesive G, instead of the gravure coating by the gravure roll 3,
Various conventionally known coating methods such as wire bar coating and hot melt coating can be appropriately adopted according to the type and form of the adhesive.

[Brief description of drawings]

FIG. 1 (a) is an explanatory view showing an example of an embodiment of a method for producing a heat-sensitive stencil printing base paper of the present invention, and FIG. 1 (b) is a main part of the production method of the above example. It is explanatory drawing which expanded the lamination process and the inversion process.

FIG. 2 is an explanatory view showing another example of the manufacturing method of the present invention.

FIG. 3 is a perspective view of a spiral roll used in the manufacturing method of the present invention.

FIG. 4 is an explanatory view showing a conventional manufacturing method.

[Explanation of symbols]

2 Laminating roll 6, 7, 10 transport rolls F thermoplastic resin film P porous support G adhesive L laminate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Nobuhiro Iwasaki             15-20 Chuo 2-chome, Joto-ku, Osaka City, Osaka Prefecture             General Co., Ltd. F-term (reference) 2H114 AB23 AB24 AB28 DA41 DA49                       DA73 EA02 EA08 FA01 GA01                 4F211 AC03 AD04 AD06 AG01 AG03                       AH53 AP06 AR04 AR07 TA13                       TC04 TC05 TD06 TD11 TH02                       TJ15 TN43 TN60 TQ03

Claims (4)

[Claims] 1. A method for producing a base paper for heat-sensitive stencil printing by continuously laminating and adhering a long thermoplastic resin film and a porous support through an adhesive and then drying the adhesive. The peripheral surface of the laminating roll, in which at least the peripheral surface of the porous support is formed of a material that is non-adhesive to the adhesive, with the adhesive surface with the thermoplastic resin film facing outside. The thermoplastic resin film is laminated at a position in the middle while being conveyed while being in contact with (lamination step), and then the following inversion step is performed on the laminated body laminated in this lamination step. Inversion step: In the step of, the sheet is conveyed while the surface on the side opposite to the side that was in contact with the roll is in contact with the peripheral surface of the conveying roll, and the conveying direction is reversed in the range of 90 to 270 ° at least once. To dry the glue Method for producing a heat-sensitive stencil sheet according to claim. 2. The heat-sensitive material according to claim 1, wherein a reversing step is continuously performed twice, and a conveying roll having a function of conveying the laminate while pulling the laminate in the axial direction of the roll is used in the first reversing step. Manufacturing method of stencil printing base paper. 3. The production of a heat-sensitive stencil sheet according to claim 1, wherein in the final reversing step, a conveying roll having a diameter of 5 to 30% of the width of the laminate and a smooth surface is used. Method. 4. A method for producing a heat-sensitive stencil printing base paper according to claim 1, wherein at least the peripheral surface of the laminate roll is formed of a polytetrafluoroethylene resin.