JP2010083136A - Plating method for stencil printing original paper and stencil printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To print continuous images easily on even an impermeable medium, in stencil printing. <P>SOLUTION: The plating method for stencil printing original paper includes forming a groove 11 having a shape with a desired printing pattern projected on a surface A by irradiating a resin film 10 which represents an original sheet for stencil printing with a laser from the surface A side and then forming a through-hole 12 for ink to pass inside the groove 11. Thereby the pattern with the shape projected into the groove 11 is printed using the plate obtained, superimposing the surface A side representing the groove-forming surface of the plate onto the printing medium, supplying ink from the surface B side representing the groove non-forming surface and filling the ink passed through the through-hole 12 inside the groove 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stencil printing method using a laser and a stencil printing method using a plate obtained thereby.

  In general, a stencil printing plate is manufactured by using a base paper (master) in which a thermoplastic resin film is laminated on a porous support, and heat-melting the thermoplastic resin film with a thermal head to form perforations. . The perforations are formed independently in the form of dots, and an image is formed by passing ink through the holes.

  In Patent Document 1, in order to reproduce a clear printed image, a heat-sensitive stencil plate is formed on the periphery of the perforated part by a film lump made of a thermoplastic resin film that has been perforated and melted, or by an unengraved part that is raised and solidified by a part thereof. A method for making a base paper is disclosed. A heat source for punching is a thermal head, and punched portions to be imaged are arranged in dots.

  When the printing medium is paper, cloth, or the like, the ink patterned in a dot shape penetrates and diffuses into the medium, and therefore, for example, a line or a solid image can be continuously formed without being interrupted in a dot shape.

  In the case of printing media (non-penetrating media), such as plastic film, coated paper, glass, metal, etc., which are difficult to permeate print media (penetrating media) with such ink permeability, continuous lines and solid images There is a problem that it cannot be formed cleanly (disconnected).

JP-A-4-265683

  A screen printing method that is a kind of stencil printing is widely used as a printing method for non-penetrating media. This screen printing plate is generally made by applying a photosensitive agent to a very fine mesh screen, baking a positive film, and developing it. In this way, the screen printing plate is formed with continuous ink passage holes rather than independent perforations, so that the above-mentioned problem does not occur even when printing on non-penetrating media.

  However, the formation of a plate film (resist) using a photosensitizer requires many steps and is complicated, and there is an inconvenience that it is an analog process.

  Therefore, the present invention has an object to provide a stencil printing method using a base plate for stencil printing that can easily print continuous images even on non-penetrable media, and a stencil printing method using a plate obtained thereby. To do.

According to one aspect of the present invention, there is provided a method for making a stencil sheet for printing using a plate having a through hole for ink passage,
The base paper is a resin film, and the resin film includes a surface on a side to be superimposed on a print medium at the time of printing, and a back surface on a side to supply ink.
Irradiating a laser beam from the surface side of the resin film to form a groove portion having a shape in which a desired printing pattern is projected on the surface, and subsequently forming a through hole for ink passage in the groove portion region. A feature is a method for making a stencil sheet.

According to another aspect of the present invention, there is provided a plate obtained by the stencil sheet making method according to the present invention, comprising a groove formed on one side and a through hole formed in the groove. Using a plate
Supplying the ink from the groove non-forming surface side by superimposing the groove forming surface side of the plate on the print medium;
A stencil printing method is provided, in which the groove portion is filled with ink that has passed through the through hole, and a pattern in which the shape of the groove portion is projected is printed.

  According to the present invention, since the groove portion is formed on the side of the plate material that overlaps the print medium, at the time of printing, the ink that has passed through the through hole is filled in the groove portion, diffused in the groove portion, and transferred to the print medium. The As a result, an image line portion in which dots (through holes) and dots are continuous can be formed on the print medium. That is, a print pattern in which the shape of the groove portion of the plate is projected can be formed. Therefore, continuous lines, characters, and images without disconnection can be printed accurately and with good reproducibility even on non-penetrating media such as resin films and metals.

  In the present invention, by using a laser, the shape and depth of the groove can be easily controlled by a digital method. Therefore, according to the present invention, the number of steps can be greatly reduced as compared with conventional screen printing, and printing on non-penetrable media can be performed easily and simply.

It is the schematic diagram which expanded partially and showed an example of the plate obtained by the plate-making method of the stencil printing base paper by this invention. It is a figure which shows typically the position processed with a laser beam in the case of performing changing the process of a groove part, and the process of a through-hole for every predetermined space | interval. (A) is a figure which shows an example of the processing order inside a contour part and a contour, (b) is a figure which shows the processing shape of the contour part processed in the processing order shown to (a). (A) is a figure which shows the other example of the process order in an outline part and an outline, (b) is a figure which shows the process shape of the outline part processed in the process order shown to (a). It is the schematic diagram which expanded and showed one process example of the method for stencil printing by this invention partially.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 schematically shows an example of a stencil sheet (plate) partially enlarged.

  The resin film 10 that is a base paper includes a front surface (A surface in FIG. 1) that overlaps the print medium during printing, and a back surface (B surface) on the ink supply side. On the A surface side of the resin film, the groove 11 is formed by irradiating laser light from the A surface side. Further, a plurality of through holes 12 are formed in the groove 11 region. The laser beam irradiation for forming the through-hole 12 is not particularly limited. However, from the viewpoint that the taper is generated, the ink can be easily removed, and the processing is performed from the same side, so that the work efficiency is high. It is preferable to be performed from the A plane side.

  The resin (plastic) film is not particularly limited, but polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polyamide, polyemulsion, polyvinylidene chloride, epoxy, polycarbonate, polyacetal, Teflon (registered trademark), etc. can be preferably used. . From the viewpoint of laser processability, a thermoplastic resin film is preferable.

  The thickness of the resin film (indicated by H1 in FIG. 1) is not particularly limited, but is preferably 4 μm or more from the viewpoint of forming the groove, and preferably 300 μm or less from the viewpoint of forming the through hole. -200 micrometers is more preferable, and 38-100 micrometers is further more preferable.

  The resin film may contain an additive for increasing the light absorbency according to the wavelength of laser light described later. For example, for visible light, it is preferable to add a colorant such as black to color the resin film.

  As a conventional stencil printing base paper, an expensive porous support made of Japanese paper fiber or the like was used by laminating a thin resin film of about a few microns to a few dozen microns, but in the present invention, A plate can also be formed of a thick film single film, and there is no need to use a porous support. In this case, the plate production process is simple and the cost of the plate can be greatly reduced. Further, the conventional support has a problem that the passage of ink from the through hole (perforated portion) is obstructed. However, if this is not used, the image reproducibility can be improved.

  In the case of screen printing, it is common to produce a plate by applying a photosensitive agent to a screen as a support and then baking a positive film and developing it by an analog method. According to this, the process can be remarkably simplified and made inexpensive.

  Although not shown in the figure, on the surface (A surface) side of the resin film 10 to be overlapped with the printing medium, a known material such as a silicone-based release agent, a fluorine-based release agent, a phosphate ester-type surfactant, or the like is used. A release layer may be provided.

  The laser source is not particularly limited, and various lasers having arbitrary beam wavelengths such as solid lasers such as ruby laser and YAG laser; gas lasers such as carbon dioxide laser and argon ion laser; excimer lasers and dye lasers can be used. .

  The specific laser apparatus is not particularly limited, and a known digital image signal input method, laser beam operation method, and the like can be used.

  The laser oscillation mode is preferably a pulse wave rather than a continuous wave because a microfabrication is easy, and a pulse wave oscillation laser is preferably used.

  From the viewpoint of workability, the laser output is preferably 0.1 to 500 W, and more preferably 1 to 200 W.

  In addition, irradiation conditions such as pulse width (irradiation time per pulse), pulse period, number of pulses (shots), and scanning speed can be set and modulated as appropriate so that the groove and the through hole can be formed according to the desired image pattern. Well, there is no particular limitation.

  The wavelength of the laser light is not particularly limited, but it is determined by the length of the wavelength whether non-thermal processing or thermal processing becomes dominant. That is, laser light with a short wavelength, such as an ultraviolet laser, excites each molecule of the resin film at the irradiation site and scatters them (laser ablation or laser sputtering) to form grooves or holes. Become dominant. According to this non-thermal processing, fine grooves or through holes can be formed in a desired shape. On the other hand, in the case of an infrared laser having a long wavelength, the thermal element is large and thermal processing becomes dominant.

  In a preferred embodiment, the wavelength of the laser beam is selected from 400 nm to 10.6 μm (10600 nm) accompanied by heat generation, in addition to the non-thermal processing by the photochemical effect. When the wavelength of the laser beam is not less than the visible light region, not only a chemical reaction but also a thermal reaction is caused to the resin film. As a result, a part of the resin film is thermally melted, and a raised portion can be formed on the periphery of the groove. The bulge on the periphery of the groove formed on the surface of the printing plate (the side overlapping with the printing medium) prevents the ink filled in the groove from protruding during printing, and forms a sharper, no-bleed pattern. be able to.

  On the other hand, if the thermal effect of the laser beam is too great, the melting or shrinking of the resin film proceeds excessively and the shape of the groove is disturbed. As a result, the reproducibility may be lowered depending on the fineness of the printed pattern. In addition, excessive melting or shrinkage of the resin film in the laser light irradiation area affects the entire film, resulting in deformation such as shrinkage of the plate, and the flatness of the plate is lowered, and the reproducibility of the printing pattern is lowered. There is a fear.

  Considering these points, the laser beam in the visible light region of 400 nm to 830 nm can be used in a well-balanced manner by taking advantage of both the fineness of the chemical reaction and the bulge formation brought about by the thermal reaction. More preferably, is used.

  In order to desirably achieve the above-described ink protrusion effect, it is preferable that the height of the bulge in the groove is 0.3 μm or more. On the other hand, if this bulge is too high, contact between the printing plate and the printing medium is hindered, and therefore it is preferably about 20 μm or less.

  The groove 11 can be preferably formed by half etching. The grooves are formed so as to have a shape in which a desired print pattern is projected.

  The depth of the groove 11 (indicated by H2 in FIG. 1) is preferably 5 to 80% with respect to the film thickness (indicated by H1 in FIG. 1) from the viewpoint of plate durability and ink film thickness control. 10 to 70% is more preferable, and 15 to 60% is more preferable.

  The depth of the groove 11 may be selected according to the characteristics of the printing medium used for printing, the method of using the printed pattern, the desired thickness of the ink layer, and the like. In general, if the groove is too shallow, it becomes difficult to fill with ink, and therefore the groove depth is preferably 2 μm or more. Thereby, an ink layer having a sufficient thickness can be formed. For example, when a conductor pattern is formed on a metal surface or the like, the groove depth is preferably about 5 to 60 μm so as not to cause a disconnection. As described above, it is preferable to select a resin film having a thickness suitable for the depth of the groove to be formed as the base paper.

  Note that at least a part of the groove 11 corresponding to the print pattern printed in one printing operation may have a different depth from the other parts. That is, the depth may be partially changed in one continuous groove portion 11, or the depths of the plurality of groove portions 11 that are formed apart from each other may be different from each other. If it does in this way, the printed matter which has different ink film thickness (thickness of an ink layer) according to the depth of the groove part 11 by one printing can be obtained.

  When screen printing is performed by moving the squeegee on the back surface (B surface) of the resin film 10 supplied with ink, a thin line extending in a direction (first direction) substantially perpendicular to the moving direction of the squeegee is printed. The groove 11 for printing and the groove 11 for printing the direction substantially parallel to the moving direction of the squeegee (second direction) may be formed so as to have the same width and depth. The ink film thickness in the printed material is not the same, and the thin film extending in the first direction tends to be thinner than the thin film extending in the second direction.

  When a conductor pattern is formed on a metal surface or the like, stable electrical characteristics can be obtained if the thin line extending in the first direction and the thin line extending in the second direction have the same line width but different ink film thickness. It may not be possible.

  Therefore, in the groove 11 formed in the resin film 10, when the width of the portion extending in the first direction and the portion extending in the second direction are substantially the same, the depth in the portion extending in the first direction is The depth in the portion extending in the second direction may be larger.

  For example, in one groove portion 11 for printing a thin line having a uniform width in which a portion extending in the first direction and a portion extending in the second direction are continuous, the depth in the portion extending in the first direction is set. , Greater than the depth in the portion extending in the second direction. In addition, in the plurality of groove portions 11 having substantially the same width, which are formed apart from each other, the depth of the groove portion 11 extending in the first direction is made larger than the depth of the groove portion 11 extending in the second direction. If it does in this way, in the printed matter obtained by screen printing, an ink film thickness can be made uniform by the thin line extended in the 1st direction, and the thin line extended in the 2nd direction.

  The shape and density of the through-holes 12 in the groove portion are such that the shape and volume of the groove portion, ink characteristics (viscosity, etc.), type, etc. are sufficient to allow ink to pass through the groove portion sufficiently. It is set appropriately according to

  The size of the through hole can be arbitrarily changed by changing the energy density of the laser beam and / or the number of irradiation pulses.

  From the viewpoint of improving the smoothness of the fine line and the solid part edge, the opening ratio of the through hole to the groove part, that is, the ratio of the through hole part area to the groove part area is preferably 20% or more. On the other hand, the open area ratio is preferably 50% or less from the viewpoint of durability of the plate. Here, the smoothness of the fine line means the degree of difference between the thickest part and the thinnest part of the line width of the fine line, and the smoothness of the solid part edge means the degree of unevenness of the edge line. When it is small, it is “smooth”.

Specifically, from the viewpoint of appropriately securing the amount of ink filled in the groove, the width L (μm) of the groove, the diameter D (μm) of the through holes, and the pitch (center distance) P between the through holes (Μm)
P <2D <2P, L <2D <2L,
It is preferable that the relationship is The pitch P between the through holes can be changed according to the pulse period and the scanning speed.

  In the present invention, as described above, the groove 11 and the through hole 12 are formed according to a desired image pattern by appropriately adjusting the irradiation conditions such as the energy density of laser light, the pulse period, and the scanning speed. The processing inner diameter of the through hole 12 tends to increase.

  Therefore, when forming the small through-holes 12, repeated striking may be performed at the same position with a laser beam having a minimum energy density necessary for processing the resin film 10. By repeatedly struck, for example, several tens of times with a laser beam having a small energy density, the through-hole 12 can be formed while keeping the machining inner diameter small.

  As described above, the present invention is characterized in that the shape of the groove is a projection of a desired print (image) pattern. That is, in the past, dots were formed corresponding to the print pattern, and a series of dots corresponded to the print pattern. However, in the present invention, the through holes (dots) pass through the ink to fill the grooves. The number and size in the groove are selected and provided.

  When forming the groove 11 and the through hole 12 in the resin film 10, first, the groove 11 having a shape in which a desired print pattern is projected is formed while moving the laser source from the processing origin, and the formation of the groove 11 is completed. Thereafter, the laser source is returned to the origin where the processing of the groove portion 11 is started, and the through holes 12 are processed sequentially. However, when processing is performed according to such a procedure, the formation position of the through hole 12 with respect to the groove portion 11 may deviate from the design position due to the influence of external factors such as a moving mechanism of the laser source.

  Accordingly, the groove 11 may be formed while moving the laser source from the processing origin, and the through holes 12 may be formed sequentially at predetermined intervals. FIG. 2 is a diagram schematically showing a position processed by a laser beam. As shown in FIG. 2, if the processing of the groove portion 11 and the processing of the through hole 12 are performed while switching at predetermined intervals, the positional accuracy of the through hole 12 with respect to the groove portion 11 is improved and the processing time is shortened. Can do.

  In addition, when processing the groove 11 (and the through hole 12) having a shape in which a desired print pattern is projected, the processing position is changed after the processing in the X direction is sequentially performed from the processing origin on the XY plane. The shift by one dot in the Y direction and the sequential processing in the X direction are repeated. For example, when processing the contour portion and the inside of the contour in the print pattern, after processing continuously in the X direction in the order shown in FIG. 3A, the processing position is shifted by one dot in the Y direction, Moreover, it repeats processing continuously in the X direction.

  When processing is performed in such an order, as shown in FIG. 3B, the edge 13 along the X direction of the contour portion of the print pattern is continuously processed with dots, and therefore, the dots are smoothly affected by heat. It tends to be a complicated shape. On the other hand, since the edge 14 along the Y direction is formed by being processed intermittently, the edge 14 tends to have an uneven shape, and it is difficult to obtain a smooth printed image compared to the edge 13 in the X direction. The same applies not only to the Y direction but also to the direction inclined with respect to the X direction.

  Therefore, as shown in FIG. 4A, the entire contour portion of the print pattern may be processed continuously, and then the inside of the contour may be processed. When processing is performed in this order, as shown in FIG. 4B, the edge 15 along the Y direction of the contour portion of the print pattern is also continuously dot-processed similarly to the edge 13 along the X direction. Therefore, it can be made into a smooth shape.

  Note that the inside of the contour may have a coarser pitch than the contour portion. Thereby, processing time can be shortened. When the inside of the contour is solid, the contour portion itself may be punched with a through hole. Thereby, processing time can be further shortened.

  As an image gradation (gradation) expression method, AM screening for fixing the number of dots and changing the size of the dots, and changing the number of dots (number of dots per unit area) by fixing the size of the dots. There is FM screening. In the conventional thermal head type thermal stencil printing, the size of the heating element of the thermal head is fixed, so that gradation can be expressed only by FM screening that changes the number of dots. On the other hand, according to the present invention in which laser drilling is performed, both the number of dots and the size can be freely changed, so that both screening methods can be employed. That is, by increasing / decreasing the number and / or size of dots, the amount of ink passing through the through hole increases / decreases, and as a result, the amount of ink filled in the groove is adjusted to express gradation. be able to. When the solid rate is 70% or less, AM screening can be performed without forming the groove.

  The type of ink used for printing is not particularly limited. In addition to various stencil printing inks (screen inks) such as emulsion, oiliness, and water, printing such as etching resist ink, solder resist ink, plating resist ink, and marking ink. Substrate ink and conductive ink for electronic precision parts can also be used. Their specific composition is not particularly limited.

  The viscosity of the ink is not particularly limited, but is preferably in the range of 0.01 to 100 Pa · s, and preferably in the range of 0.1 to 50 Pa · s from the viewpoint of holding the ink on the plate and passing through the through hole. More preferably, it is in the range of 0.5 to 30 Pa · s. The viscosity is a value measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) at a temperature of 23 ° C. and a shear rate of 10 rpm.

  The type of printing medium (printed material or media) is not particularly limited, and any paper, cloth, leather, plastic film, metal product, wood product, rubber product, ceramic product (ceramics, glass, enamel), etc. Can be selected. In the present invention, it is advantageous that a good image can be formed even on a non-penetrable medium.

  The shape of the print medium is not limited, and the plate to be used is a flexible plate made of a resin film, so that it can be printed well even on a curved print medium.

  FIG. 2 schematically shows a process example of the stencil printing method according to the present invention. As shown in the figure, the groove forming surface side of the plate (plate-making product) 10 is superimposed on the printing medium 30, and the ink 20 is supplied from the groove non-forming surface side. The ink passes through the through hole 12 and fills the groove (the state where the groove is filled with ink is not shown). Then, the ink filled in the groove is transferred to the print medium 30, and a pattern 21 in which the shape of the groove is projected is printed.

  The printing machine to be used may be a flat screen printing machine or a rotary screen printing machine, and is not particularly limited.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

(1) Preparation of an original plate A screen printing plate aluminum frame (550 x 650 mm) is bonded to a polyester film (Lumirror X30 manufactured by Toray Industries, Inc., biaxially stretched polyethylene terephthalate, film thickness 38 μm) and fixed for screen printing. An original plate was prepared.

(2) Plate making <Examples 1, 3, 8-13, Comparative Example 2>
The original plate was subjected to laser processing under appropriate processing conditions using a green laser (LP-G050 manufactured by SUNX Co., Ltd.) to obtain a plate having the shape shown in the table.

  In addition, the groove part of Examples 8-12 was formed in one original plate. These groove portions were formed along a direction (first direction) perpendicular to the moving direction of the squeegee.

  In Example 13 and Comparative Example 2, the groove portion extending in the direction perpendicular to the moving direction of the squeegee (first direction) and the groove portion extending in the parallel direction (second direction) were each formed on one original plate. .

<Examples 2, 5-7, Comparative Example 1>
Using the TEA CO ₂ laser (Lumonics IMPACT L500 manufactured by Sumitomo Heavy Industries Mechatronics Co., Ltd.), laser processing was performed on the original plate under appropriate processing conditions to obtain a plate having the shape shown in the table.

<Example 4>
Using the excimer laser (LUMONICS INDEX848 manufactured by Sumitomo Heavy Industries Mechatronics Co., Ltd.) on the original plate, laser processing was performed under appropriate processing conditions to obtain a plate having the shape shown in the table.

(3) Printing A plate frame is formed so that the groove-forming surface of the screen-printed plate (plate-making product) made on the plate is overlaid on a film that is a non-penetrable medium (Lumilar manufactured by Toray Industries, Inc.), and the gap therebetween is 3.0 mm. Fixed. Next, a silver paste (Dotite FA-353N manufactured by Fujikura Kasei Co., Ltd.) is supplied onto the plate on the non-grooved surface side, and using a squeegee (urethane rubber), the squeegee is inclined by 45 ° with respect to the plate and pressed. Printing was done. The fifth printed material was sampled.

(4) Measurement of plate making shape <Groove width L>
Using a digital HF microscope VH-8000 (manufactured by Keyence Corporation), a still image of the groove portion of the plate-making product was captured at a magnification of 450 times. Next, using the two-point distance measurement mode, the distance between the ridge apexes of the edge in the longitudinal direction of the groove was measured and defined as the groove width (average value of five locations).

<Groove depth H2>
Using a color 3D laser microscope VK-8710 (manufactured by Keyence Co., Ltd.), the height of the film surface and the groove bottom surface in the groove portion of the plate-making product was measured at a magnification of 200 times, and the groove depth was obtained from the difference between the two ( Average value of 5 locations).

<Through hole diameter D>
Using a digital HF microscope VH-8000 (manufactured by Keyence Corporation), a still image of the groove portion of the plate-making product was captured at a magnification of 450 times. Next, the diameter of the through hole was measured using the two-point distance measurement mode (average value of five locations).

<Uplift height>
Using a color 3D laser microscope VK-8710 (manufactured by Keyence Co., Ltd.), the height of the film surface in the groove part of the plate-making product and the highest part of the raised part is measured at a magnification of 500 times, and the height of the raised part is determined from the difference between the two. Obtained (average of 5 locations).

<Pitch P between through holes>
Using a digital HF microscope VH-8000 (manufactured by Keyence Co., Ltd.), a still image of the groove part of the plate making part was captured at a magnification of 450 times. Next, by using the distance measurement mode between two points, the distance between the centers of the through holes was measured to obtain a pitch between the through holes (average value of five locations).

<Aperture ratio>
(D / 2) Calculated from ² · π / (L · P) × 100 (%).

(5) Evaluation of printed matter <Presence or absence of plate deformation>
Depending on the degree of deformation (shrinkage) of the film caused by laser irradiation, the case of almost no shrinkage was evaluated as A, and the case of shrinkage was evaluated as B.

<Presence of disconnection>
Visual evaluation determines the presence or absence of disconnection, C indicates that the printed thin line is disconnected, B indicates that the line width is very thin but not disconnected, and the line width is stable. The case where no disconnection was observed was designated as A.

<Presence of bleeding>
The blur of the thin line printed by visual evaluation was evaluated. The case where the thickness was recognized as B, the case where the thickness was slightly recognized as B, and the case where the thickness was not recognized as A was evaluated according to the thickness of the line width when comparing the groove portion of the plate-making product with the thin line of the printed material.

<Smoothness of fine lines>
The shape of the edge of the printed fine line was visually evaluated. The case where the line width of the thinnest part of the fine line is less than 50% of the line width of the thickest part is evaluated as C, the case of 50% or more and less than 70% is evaluated as B, and the case of 70% or more is evaluated as A. .

(6) Measurement of printed shape <Line width>
Using a digital HF microscope VH-8000 (manufactured by Keyence Co., Ltd.), a still image of a fine line of the printed material was captured at a magnification of 450 times. Next, the line width of the thin line of the printed material was measured using the distance measurement mode between two points (average value of five locations).

<Ink film thickness>
Using a color 3D laser microscope VK-8710 (manufactured by Keyence Co., Ltd.), the height of the film surface and the top of the ink in the fine line of the printed matter was measured at a magnification of 200 times, and the ink film thickness was obtained from the difference between the two. (Average of 5 locations).

The above results are shown in the table.

  According to Examples 1 to 4, fine lines without disconnection could be printed even on non-permeable printing media. Furthermore, in Examples 1 to 3 in which the raised portions were formed on the peripheral edge of the groove portion, it was possible to form an image without bleeding. On the other hand, in Comparative Example 1 in which no groove was formed, disconnection occurred in the thin line.

  In Examples 5 and 6 in which the hole area ratio was 20% or more, smoother fine lines could be printed than in Example 7 in which the hole area ratio was 20% or less.

  According to Examples 8 to 12, fine lines having different ink film thicknesses could be printed by one printing by forming groove portions having different groove depths H2 in one plate. In Examples 8 to 10, fine lines having the same line width and different ink film thickness depending on the groove depth H2 are obtained. In Examples 11 and 12, the ink film thickness is approximately the same and the line width is the groove width L. Depending on the case, different thin lines were obtained.

  In Example 13, the groove portion extending in the first direction and the groove portion extending in the second direction having the same groove width L are set such that the groove depth H2 is larger in the groove portion extending in the first direction. As a result of the formation, the line width and the ink film thickness of the fine line extending in the first direction and the fine line extending in the second direction could be made comparable.

  On the other hand, in Comparative Example 2 in which the groove portion extending in the first direction and the groove portion extending in the second direction are formed so that the groove width L and the groove depth H2 are the same, the thin line extending in the second direction In this case, the ink film thickness was larger than that of the fine line extending in the first direction.

10 resin film 11 groove 12 through hole

Claims (9)

A method for making a base paper for stencil printing, in which printing is performed using a plate having through holes for ink passage,
The base paper is a resin film, and the resin film includes a surface on a side to be superimposed on a print medium at the time of printing, and a back surface on a side to supply ink.
Irradiating a laser beam from the surface side of the resin film to form a groove portion having a shape in which a desired printing pattern is projected on the surface, and subsequently forming a through hole for ink passage in the groove portion region. A method for making a stencil sheet, which is characterized.   2. The stencil sheet making method according to claim 1, wherein the laser light is irradiated using a pulsed wave laser and the wavelength is 400 nm to 10.6 μm.   The stencil sheet making method according to claim 2, wherein the laser beam has a wavelength of 400 nm to 830 nm.   The stencil sheet making method according to claim 2 or 3, wherein a bulge made of the resin film melted by irradiation with the laser beam is provided at a peripheral edge of the groove portion.   The method for making a stencil sheet for stencil printing according to claim 4, wherein the height of the raised portion of the groove is 0.3 μm or more.   The method for making a stencil sheet for stencil printing according to any one of claims 1 to 5, wherein an opening ratio of the through hole with respect to the groove is 20% or more.   The stencil sheet making method according to any one of claims 1 to 6, wherein the groove is formed so that at least a part thereof is different in depth from other parts.   A portion extending in a first direction substantially perpendicular to the moving direction of the squeegee when printing is performed by moving the squeegee on the back surface of the resin film supplied with ink, and the movement of the squeegee When the groove width of the portion extending in the second direction substantially parallel to the direction is substantially the same, the depth in the portion extending in the first direction is greater than the depth in the portion extending in the second direction. The stencil sheet making method according to claim 7, wherein the stencil sheet is formed so as to be larger. A plate obtained by the plate making method of a stencil printing base paper according to any one of claims 1 to 8, wherein a plate having a groove portion formed on one side and a through hole formed in the groove portion is used. ,
Supplying the ink from the groove non-forming surface side by superimposing the groove forming surface side of the plate on the print medium;
A stencil printing method, wherein the groove portion is filled with ink that has passed through the through hole, and a pattern in which the shape of the groove portion is projected is printed.

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