JP4680668B2 - Manufacturing method of printing blanket - Google Patents

Description

  In the present invention, the ink is applied to the surface of the printing blanket, and then brought into contact with the intaglio, and then the unnecessary portion of the ink is transferred to the intaglio and removed, and then the ink remaining on the surface is transferred to the surface of the substrate. The present invention relates to a method for manufacturing a printing blanket used in a printing method.

  In recent years, as one type of offset printing method, ink is applied to the surface of a printing blanket, and then brought into contact with the intaglio, so that the ink in contact with the convex portions other than the concave pattern of the intaglio is transferred to the intaglio side and removed. After that, since the printing method for transferring the ink corresponding to the concave pattern remaining on the surface to the surface of the substrate to be printed is possible to print a fine pattern, for example, printing a color filter for a liquid crystal display element, etc. In Japan.

  One of the features of this printing method is that the pressure (printing pressure) during printing can be significantly reduced. However, when the printing pressure is low, the influence of the thickness and surface roughness unevenness and variation of the surface printing layer of the printing blanket on the printing result increases. Therefore, the printing blanket used in the above printing method is required to have higher accuracy. That is, the surface printing layer of the printing blanket is required to have a uniform thickness and a constant surface roughness.

  In addition, a printing blanket used for normal precision printing applications is provided with a porous layer formed separately from the printing blanket, and an under blanket for adjusting the amount and printing pressure of the printing blanket. However, in the above printing method, if any gap is generated between the two, it affects the printing result, so the porous layer is printed. It must be formed integrally with the blanket substrate. That is, a printing blanket in which a porous layer is integrally formed on one surface of a substrate and a surface printing layer is integrally formed on the opposite surface is required. And when forming a porous layer integrally, it is calculated | required that the internal structure and thickness are uniform. In addition, when a porous layer is formed on one side of a base material and a surface printing layer is formed thereon, the surface printing layer becomes too soft and good printing cannot be performed. As mentioned above, it is limited to the structure which formed the porous layer in the single side | surface of the base material, and the surface printing layer in the opposite surface.

Recently, in order to reduce the manufacturing cost of liquid crystal display elements, etc., it is considered to perform so-called multi-sided printing, which simultaneously prints on the surface of a large number of printed materials (such as glass substrates in the case of liquid crystal display elements) Correspondingly, there is a tendency to increase the size of the printing blanket.
In Patent Document 1, a base material in which a porous layer is integrally formed on one side and a film such as PET having releasability with respect to rubber forming a surface printing layer are charged in the mold, After injecting the material that forms the surface print layer between the base material and the film and forming it into a layer, the film is peeled off from the surface of the surface print layer of the laminate taken out of the mold. The formation of a surface printing layer having excellent surface smoothness is described.

However, since a mold is used in the above method, the larger the printing blanket is, the larger the mold is required, and the manufacturing cost of the printing blanket increases correspondingly. There is a problem that it becomes difficult to obtain the accuracy of the thickness of the surface print layer.
Patent Document 2 describes a method in which a liquid silicone rubber is applied onto a substrate, the coated surface is held horizontally and self-leveling, and then cured to form a surface printed layer. According to this method, a surface printing layer of a printing blanket having a large area can be formed without using a large-scale mold. Moreover, the thickness can also be made uniform. However, Patent Document 2 does not describe forming a porous layer.

As described above, the ink is applied to the surface of the printing blanket, then brought into contact with the intaglio, and the unnecessary portion of ink is transferred to the intaglio and removed, and then the ink remaining on the surface is removed from the substrate. In the printing method for transferring to the surface, since the porous layer needs to be formed integrally with the substrate of the printing blanket, the production method of Patent Document 2 cannot produce the intended printing blanket. .
JP-A-8-112981 (Claim 1, columns 0016 to 0017, FIG. 5) JP 2003-136856 (Claim 1, columns 0011, columns 0014 to 0017, FIGS. 1 and 3 to 10)

  The object of the present invention is to apply ink to the surface of a printing blanket, and then contact the intaglio to transfer the unnecessary portion of ink to the intaglio and remove the ink remaining on the surface of the substrate. A surface printing layer, a base material, and a porous layer, which are used in a printing method for transferring to a substrate, are integrally formed, and a printing blanket in which each layer is formed accurately and uniformly is manufactured easily and inexpensively. It is to provide a method for manufacturing a printing blanket.

  According to the first aspect of the present invention, after ink is applied to the surface of the printing blanket, and then brought into contact with the intaglio, the unnecessary portion of ink is transferred to the intaglio and removed, and then the ink remaining on the surface is removed. A printing blanket manufacturing method comprising a porous layer on one side of a substrate and a surface printing layer on the opposite side, which is used in a printing method for transferring to the surface of the substrate. A step of preparing a liquid mixture to which 1 to 30 parts by weight of spheres are added; and while applying the mixture to one side of the substrate and holding the substrate horizontally, the liquid silicone rubber is cured, A method for producing a printing blanket, comprising the step of forming an integrated porous layer.

The invention according to claim 2 is the method for producing a printing blanket according to claim 1, wherein the liquid silicone rubber is cured at a temperature lower than the thermal deformation temperature of the hollow microspheres to form a porous layer.
In the invention according to claim 3, the liquid silicone rubber is applied to the surface of the substrate opposite to the side on which the porous layer is integrated, and the liquid silicone rubber is cured while the substrate is held horizontally. The method for producing a printing blanket according to claim 1, further comprising a step of forming a surface printing layer integrated with the substrate.

The invention according to claim 4 is the method for producing a printing blanket according to claim 3, wherein the liquid silicone rubber is cured at a temperature lower than the thermal deformation temperature of the hollow microsphere to form a surface printing layer.
The invention according to claim 5 includes the step of forming a fluororesin layer on the surface of the porous layer prior to forming the surface print layer on the opposite surface of the substrate. Is the method.

In the first aspect of the invention, the mixture that forms the porous layer is applied to one side of the base material, and the base material is held horizontally, and the thickness thereof is uniformly leveled by the weight of the mixture. By curing the liquid silicone rubber in the state, a porous layer integrated with the base material is formed. Therefore, the thickness of the porous layer can be made uniform.
In addition, the hollow microspheres blended in the liquid mixture have a predetermined thickness direction in the mixture due to their buoyancy before the liquid silicone rubber is cured after the mixture is applied to one side of the substrate. It is fixed in a porous layer formed by curing of the liquid silicone rubber while being uniformly distributed in the region. Therefore, the internal structure of the porous layer can be made uniform. Moreover, it is possible to form a porous layer of a printing blanket with a large area corresponding to multiple chamfering without using a large mold.

Therefore, according to the first aspect of the invention, the printing blanket in which the surface printing layer, the base material, and the porous layer are integrally formed, and each layer is formed accurately and uniformly, It can be manufactured at low cost.
According to the invention described in claim 2, the hollow microspheres are prevented from irregularly expanding and foaming due to the heat at the time of curing of the liquid silicone rubber. Can form a uniform porous layer.

  According to the invention described in claim 3, since not only the porous layer but also the surface printing layer is formed integrally with the base material by the same method, the thickness thereof can be made uniform. it can. Moreover, it is possible to form a surface printing layer of a printing blanket with a large area corresponding to multiple chamfering without using a large mold. Therefore, according to the invention of claim 3, the surface printing layer, the base material, and the porous layer are integrally formed, and each layer is accurately and uniformly formed. It becomes possible to manufacture simply and inexpensively.

According to the invention of claim 4, the hollow microspheres in the previously formed porous layer expand irregularly by the heat at the time of curing of the liquid silicone rubber when forming the surface print layer. It is possible to form a porous layer having a uniform thickness and internal structure.
Furthermore, according to the invention described in claim 5, the thickness of the surface print layer can be made more uniform. That is, there may be some stickiness remaining on the surface of the porous layer immediately after the formation, and even if the stickiness does not remain, for example, in order to form a surface print layer, the substrate and the porous layer In many cases, the laminate with the layer is poorly slid against the surface of a horizontal table or the like on which the porous layer is placed. Therefore, the air is caught between the porous layer and the horizontal table, etc., and the opposite surface of the base material that is held on the horizontal table is uneven or wrinkled. The opposite surface may be uneven due to the influence of minute dust or the like attached to the surface of the porous layer, which may hinder the formation of a surface print layer having a uniform thickness.

  On the other hand, according to the invention described in claim 5, since the layer of the fluorine-based resin having a good slip property is formed on the surface of the porous layer prior to the formation of the surface print layer, With the porous layer facing down, it improves the sliding property when held on a horizontal platform, etc., prevents adhesion of minute dust, etc., and can hold the laminate as horizontally as possible The thickness of the printed surface printed layer can be made even more uniform.

  The fluororesin layer also improves the slipping property when a printing blanket manufactured by forming a surface printing layer on the opposite surface of the substrate is wrapped around the outer periphery of a blanket cylinder of an offset printing machine. To do. For this reason, it is possible to perform good printing by winding the printing blanket around the outer periphery of the blanket cylinder with good workability and as uniform thickness as possible.

  In the production method of the present invention, first, a base material for a printing blanket is prepared. As the base material, it is preferable to use a film having a low elasticity in order to suppress the expansion and contraction of the surface printing layer and the porous layer and improve the printing accuracy. In addition, as a film with low stretchability, for example, when a printing blanket is wound around a blanket cylinder under tension, the porous layer and the surface printing layer are reinforced, and both layers are irregularly stretched in the surface direction. Any of various films capable of suppressing the above can be used.

In particular, a thin metal plate (metal foil) such as aluminum or stainless steel, or Japanese Industrial Standard JIS _K7127-1999 “Plastics-Test Method for Tensile Properties Part 3: Test Conditions for Films and Sheets (ISO 527-3 _{: 1995)} ) ”, A resin film having a tensile elastic modulus at room temperature (23 ± 1 ° C.) of 1000 MPa or more, particularly 2000 to 5000 MPa, which is measured by the test method prescribed in“ Is done. Examples of the resin film having a tensile elastic modulus in the above range include a polyester film such as polyethylene terephthalate (PET), a polycarbonate film, and the like.

  Although the thickness of a base material is not limited to this, It is preferable that it is 0.1-0.5 mm, and it is further more preferable that it is 0.2-0.45 mm. If the thickness of the base material is less than this range, the porous layer and the surface print layer by the base material may be reinforced and the effect of suppressing both layers from expanding and contracting irregularly in the surface direction may be insufficient. is there. Further, the stiffness of the printing blanket becomes weak and it is easy to bend, and there is a possibility that the work of winding the blanket cylinder becomes difficult. Further, when the thickness of the base material exceeds the above range, the stiffness of the printing blanket becomes too strong, and on the contrary, there is a possibility that the work of winding the blanket cylinder becomes difficult.

Next, in the manufacturing method of this invention, the liquid mixture used as the basis of the porous layer formed in the single side | surface of the said base material is prepared. The mixture is prepared by blending liquid silicone rubber and hollow microspheres and mixing so that the hollow microspheres are uniformly dispersed in the liquid silicone rubber.
Examples of the liquid silicone rubber include, for example, a condensation type one-liquid type or two-liquid type liquid silicone rubber, an addition type one-liquid type, two-liquid type, or three, classified according to the cured form and the state before curing. Any of room temperature curable (RTV) liquid silicones such as liquid type liquid silicone rubber and ultraviolet curable one liquid type liquid silicone rubber can be used. However, in consideration of making the thickness and internal structure of the porous layer even more uniform, it is preferable to use an addition type liquid silicone rubber that does not generate gas during curing.

  Further, as the hollow microsphere, for example, the shell disclosed in US Pat. No. 4,770,928, JP-A-3-244595, JP-A-7-505341, etc. is made of a thermoplastic resin. Any of various conventionally known hollow microspheres formed can be used. In particular, in consideration of resistance to ink, etc., homopolymers of polymerizable monomers such as vinylidene chloride and (meth) acrylonitrile, copolymers of two types of monomers containing these monomers, multiples of three or more types of monomers Hollow microspheres having a shell formed of a copolymer or the like are preferred.

The particle diameter of the hollow microsphere is not particularly limited, but in order to satisfactorily exert the effect of adjusting the printing pressure by the porous layer, the average particle diameter is 20 to 200 μm, particularly 40 to 150 μm. Is preferred. In the case of unfoamed hollow microspheres described below, the particle size is the particle size after heating and foaming.
Examples of the hollow microspheres include the Expandance series hollow microspheres manufactured by Nobel, or the hollow microspheres manufactured by Matsumoto Yushi Seiyaku Co., Ltd. Both of these hollow microspheres are a non-foamed material in which an organic solvent that becomes a void is enclosed in a thermoplastic resin shell, and the organic solvent is vaporized by heating. In the present invention, any of these can be used. In the case of using the former non-foamed hollow microspheres, the organic solvent in the shell is vaporized by heating before forming the coating liquid in addition to the liquid silicone rubber, so that the hollow microspheres have a predetermined shape. It is preferable to foam to a particle size.

  The hollow microspheres need to be blended at a ratio of 1 to 30 parts by weight with respect to 100 parts by weight of the liquid silicone rubber. When the mixing ratio of the hollow microspheres is less than this range, the effect of adjusting the printing pressure by the porous layer cannot be obtained. On the other hand, when the blending ratio of the hollow microspheres exceeds this range, the porous layer becomes too soft and the printing accuracy is lowered. In addition, the viscosity of the mixture of liquid silicone rubber and hollow microspheres becomes too high, and the mixture is evenly applied to one side of the substrate, or the thickness of the applied mixture is evenly balanced by its own weight. The hollow microspheres cannot be uniformly distributed by their buoyancy. Therefore, there is a problem that a porous layer having a uniform thickness and internal structure cannot be obtained.

  In consideration of forming a porous layer having a more uniform thickness and internal structure, excellent printing accuracy, and excellent printing pressure, the hollow microsphere is a liquid silicone rubber. It is preferable to mix | blend in the ratio of 2-25 weight part with respect to 100 weight part, especially 5-20 weight part. Further, the mixture may contain a cyclic silicone oil or the like in order to adjust the viscosity or the like.

  Next, in the manufacturing method of the present invention, a liquid mixture containing liquid silicone rubber and hollow microspheres is applied to one side of the base material, and the liquid silicone rubber is cured while the base material is held horizontally. Let Specifically, for example, after applying the mixture to a predetermined thickness on one surface of the base material, the liquid silicone rubber is cured in a state where the base material is horizontally held by being placed on a horizontal table. Alternatively, in a state where the substrate is first held on a horizontal table and held horizontally, the mixture is applied to a predetermined thickness on one side thereof to cure the liquid silicone rubber.

  Then, the mixture is cured in a state where the thickness is uniformly leveled by its own weight, and the hollow microspheres in the mixture are uniformly distributed in a predetermined region in the thickness direction by their buoyancy, Since it is fixed in the layer, a porous layer having a uniform thickness and internal structure and integrated with the base material can be easily formed without using a large mold or the like.

  In order to apply the mixture to one side of the substrate, for example, a normal application method using a roll coater, a bar coater, a flow coater, a gravure coater, a spray, an applicator or the like can be employed. Application | coating may be performed at once and may be performed in several steps. In addition, the base material may be simply placed on a horizontal base, but it prevents the base material from sagging and curling, and curling due to shrinkage when the liquid silicone rubber is cured, so that the base material is leveled. In order to maintain, it is preferable to fix the base material in close contact with the horizontal table. In order to fix the base material in close contact with the horizontal base, for example, a method of attaching the base material to the surface of the horizontal base under tension, a hole or groove for suction on the horizontal base. And a method of sucking the air between the horizontal base and the base material through the holes and grooves so that the base material is brought into close contact with the surface of the horizontal base.

The liquid silicone rubber is preferably cured at a temperature lower than the thermal deformation temperature of the hollow microspheres. As a result, the hollow microspheres are prevented from irregularly expanding or foaming due to heat at the time of curing of the liquid silicone rubber, thereby forming a porous layer having a more uniform thickness and internal structure. be able to.
The thermal deformation temperature of the hollow microsphere is, for example, when a predetermined amount of the hollow microsphere is heated for a certain period of time (about 30 minutes) under an atmospheric pressure condition where no pressure is applied, such as in an oven maintained at a constant temperature. Within this fixed time, the shell of the thermoplastic resin that forms the hollow microspheres softens and melts, and the hollow microspheres expand and break, or a large number of hollow microspheres aggregate and integrate by fusion. It shall be specified at the lowest temperature at which the phenomenon occurs.

  As the name suggests, room temperature curable liquid silicone rubber can be cured at room temperature (23 ± 1 ° C.). Therefore, after applying the coating liquid, it is usually heated for a certain period of time in a room temperature environment without heating. It is preferable that the porous layer is formed by allowing to stand and curing reaction, in order to more reliably prevent the hollow microspheres from expanding and breaking, and to omit the thermal energy required for the curing step. However, for example, the addition type liquid silicone rubber can increase the reaction rate of the curing reaction by heating, so that the curing reaction is accelerated by heating within the temperature range below the thermal deformation temperature of the hollow microsphere described above. By doing so, the curing time can be shortened, and the productivity of the porous layer and thus the printing blanket can be improved.

  The mixture from which the porous layer is based may be applied directly to one side of the substrate, or may be applied after forming an intermediate layer in advance on one side of the substrate. As an intermediate | middle layer, the various layers which can laminate | stack a porous layer on the single side | surface of a base material with sufficient adhesiveness firmly are mentioned. Specifically, from materials having excellent adhesion to the metal or resin forming the base material, or compatibility to the resin forming the base material, and also excellent adhesion to the silicone rubber forming the porous layer, or compatibility. A primer layer, an adhesive layer having self-adhesiveness or tackiness, and the like are suitably employed as the intermediate layer.

  Among these, examples of the primer layer include a silane coupling agent layer. Examples of the adhesive layer include a silicone rubber layer. The intermediate layer can be formed to have an arbitrary thickness. Further, when the porous layer is formed by applying the mixture directly on one side of the base material, omitting the intermediate layer, for example, the surface of the base material is physically or chemically surface-treated, It is preferable to improve the adhesion of the porous layer to the substrate by imparting affinity to the silicone rubber.

  Although the thickness of a porous layer is not limited to this, It is 0.05-2 mm, It is preferable that it is especially 0.3-1 mm. If the thickness of the porous layer is less than this range, the effect of forming the porous layer, that is, the effect of adjusting the amount of printing blanket and the printing pressure may not be sufficiently obtained. In addition, by increasing the thickness of the printing blanket, the stiffness of the printing blanket is strengthened, and the effect of making it difficult to bend particularly when the area is increased cannot be sufficiently obtained, so there is a possibility that the work of winding around the blanket cylinder may be difficult. .

In addition, when the thickness of the porous layer exceeds the above range, the thickness of the base material is relatively too small, and the porous layer and the surface printed layer are reinforced by the base material. There is a possibility that the effect of suppressing irregular expansion and contraction in the surface direction will be insufficient, or the stiffness of the printing blanket will be weakened and bend easily.
Next, in the present invention, a surface printing layer is formed on the opposite surface of the substrate, but prior to that, it is preferable to form a fluororesin layer on the surface of the porous layer. Thereby, as explained above, the surface of the porous layer is given good slipperiness, and the laminate of the base material and the porous layer is placed on the horizontal table with the porous layer facing down. Hold the sheet as horizontally as possible to form a surface printing layer with a more uniform thickness on the opposite surface of the substrate, or to print a blanket manufactured by forming a surface printing layer on the outer periphery of the blanket cylinder of an offset printing press. It is possible to perform good printing with good workability and with a uniform thickness as much as possible.

  The fluororesin layer is formed on the surface of the porous layer by continuously holding the substrate on a horizontal base to form a porous layer, and then maintaining the horizontal state. This is preferable for making the thickness of the layer as uniform as possible. In order to form the fluororesin layer, various coating methods can be adopted. In particular, it is preferable to apply the coating as thinly as possible using an air gun or a spray in order to make the thickness as uniform as possible.

  The thickness of the fluororesin layer is preferably 0.5 to 10 μm. As described above, the fluororesin layer is preferably as thin as possible. However, if the thickness of the layer is less than this range, there is a possibility of causing a problem in strength. When the printing blanket is wrapped around the outer periphery of the blanket cylinder of an offset printing press, the fluororesin layer is likely to be damaged, so that the printing blanket has a good workability and has a uniform thickness as much as possible. There is a risk that good printing will not be possible.

  In addition, when the thickness of the fluororesin layer exceeds the above range, the thickness tends to vary. When the thickness varies, the base printed layer is formed on the opposite surface of the substrate. Unevenness in the material can be generated, making it impossible to form a surface printing layer with a uniform thickness, or the manufactured printing blanket is wrapped around the outer periphery of the blanket cylinder of an offset printing press with good workability and with a uniform thickness as much as possible Therefore, there is a risk that good printing cannot be performed.

Examples of the fluorine-based resin include one or two of a tetrafluoroethylene resin (PTFE), a tetrafluoroethylene-hexafluoropropylene copolymer (FEP), a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and the like. More than species.
The surface print layer is formed non-porous. Such a non-porous surface printed layer can be formed by various forming methods. In particular, the liquid silicone rubber is applied to the opposite surface of the base material and the base material is held horizontally. A method of curing the silicone rubber to form a surface print layer integrated with the base material is suitably employed. Specifically, for example, after applying liquid silicone rubber to a predetermined thickness on the opposite surface of the substrate with the front and back reversed, the substrate is held horizontally by being fixed on a horizontal table or the like. The liquid silicone rubber is cured, or the base material is first fixed on a horizontal base and held horizontally, and then the liquid silicone rubber is applied on one side to a predetermined thickness and cured. By doing so, a surface print layer is formed. According to this method, a surface printed layer having a uniform thickness can be easily formed without using a large mold or the like.

  As the liquid silicone rubber, various room temperature curable liquid silicone rubbers used in the porous layer can be used. In order to adjust the viscosity of the liquid silicone rubber, a cyclic silicone oil or the like may be blended. The method for applying the liquid silicone rubber and the method for fixing the substrate on the horizontal base may be the same as described above. An intermediate layer similar to the above may be interposed between the substrate and the surface print layer.

The liquid silicone rubber is preferably cured at a temperature lower than the thermal deformation temperature of the hollow microspheres. This prevents the hollow microspheres in the previously formed porous layer from irregularly expanding or foaming due to the heat at the time of curing of the liquid silicone rubber when forming the surface print layer. Thus, a porous layer having a uniform thickness and internal structure can be formed.
As described above, since room temperature curable liquid silicone rubber can be cured at room temperature, the surface printing layer is usually applied as it is in a room temperature environment without heating after applying the coating liquid. It is preferable to leave it for a certain period of time and carry out a curing reaction in terms of more reliably preventing the hollow microspheres from expanding and breaking bubbles and eliminating the heat energy required for the curing step. However, while using an addition-type liquid silicone rubber, the curing time is shortened by heating within a temperature range below the thermal deformation temperature of the hollow microsphere, thereby shortening the curing time, As a result, productivity of the printing blanket can also be improved.

  Although the thickness of a surface printing layer is not limited to this, It is preferable that it is 0.01-1.2 mm, especially 0.1-1 mm. In order to form a surface printing layer having a thickness less than this range, the amount of liquid silicone rubber applied must be very small, leveling properties are reduced, and uniformity of the thickness of the surface printing layer is impaired. There is a fear. Moreover, when thickness exceeds this range, there exists a possibility that the effect of adjusting the printing pressure by a porous layer may not fully be acquired.

  The total thickness of the printing blanket provided with each of the above layers is preferably 0.7 to 3 mm, and more preferably 0.9 to 2 mm. If the thickness of the printing blanket is less than this range, the printing blanket tailoring amount and printing pressure are adjusted, and the thickness of the printing blanket is increased to strengthen the stiffness and make it difficult to bend, especially when the area is increased. Can not be obtained sufficiently, it may be difficult to wrap around the blanket cylinder. Further, when the thickness of the printing blanket exceeds the above range, the stiffness becomes too strong, and it may be difficult to wind the blanket cylinder.

As described above, the printing blanket manufactured by the manufacturing method of the present invention is applied with ink on the entire surface of the printing blanket, and then brought into contact with the intaglio to transfer unnecessary ink to the intaglio. After being removed, the ink remaining on the surface is used in a printing method in which the ink is transferred to the surface of the printing medium.
At this time, according to the manufacturing method of the present invention, the porous layer is formed in a uniform thickness and internal structure, and the surface print layer is formed in a uniform thickness. However, it is possible to perform good printing.

Example 1:
Add 10 parts by weight of hollow microspheres (MFL80CA manufactured by Matsumoto Yushi Co., Ltd., heat distortion temperature 140-150 ° C.) to 100 parts by weight of addition-type liquid silicone rubber (KE1606 manufactured by Shin-Etsu Silicone), and mix to disperse uniformly. Then, 10 parts by weight of the curing agent for liquid silicone rubber was further added to prepare a liquid mixture for the porous layer.

  Next, this mixture was placed on a horizontal base provided with a large number of holes for suction, sucked and adhered to the surface of the horizontal base, and a polyethylene terephthalate (PET) film having a thickness of 0.30 mm. The thickness of the exposed upper surface is 120 cm × 150 cm using a bar coater and then left standing at room temperature (23 ± 1 ° C.) for 24 hours to cure the liquid silicone rubber. A 7 mm porous layer was formed.

  Next, a coating solution containing 4% by weight of PTFE and 96% by weight of solvent was applied to the surface of the formed porous layer using a spray while maintaining the state in which the PET film was in close contact with the surface of the horizontal base. After drying at room temperature for 1 hour to form a PTFE layer having a thickness of 5 μm, the substrate was placed on a horizontal table again with the opposite side upside down and suctioned. It was made to adhere to the surface of a horizontal base. And after apply | coating the liquid mixture for the surface printing layer which mix | blended 100 weight part of the same addition type liquid silicone rubbers and the hardening | curing agent 10 weight part on the said opposite surface using a bar coater, A liquid blanket rubber was cured by allowing to stand at room temperature (23 ± 1 ° C.) for 24 hours to form a non-porous surface printing layer having a thickness of 0.7 mm, and a printing blanket was produced.

The thickness of the manufactured printing blanket was measured with a displacement measuring instrument made by Keyence Corporation at a total of 154 points at 10 cm intervals in the plane, and the difference between the maximum value and the minimum value was obtained. 0.031 mm, and the thickness was confirmed to be uniform.
Next, this printing blanket was mounted on a blanket cylinder of a printing machine corresponding to the printing method described above. As the intaglio, a flat plate having a concave pattern with a depth of 5 μm and a line width of 20 μm was used. Then, in a state where ink is applied to the entire surface of the printing blanket, the surface of the printing blanket and the intaglio plate is transferred after the ink on the intaglio plate is rolled to transfer the ink in contact with the convex portions other than the concave pattern of the intaglio plate to the intaglio plate side. Was observed. As a result, the ink corresponding to the concave pattern of the intaglio is satisfactorily left on the surface of the printing blanket with a substantially uniform thickness, and the ink in contact with the convex parts other than the concave pattern is well transferred to the intaglio side. I was able to.

Example 2:
A liquid mixture for the porous layer was prepared in the same manner as in Example 1 except that the amount of hollow microspheres relative to 100 parts by weight of the liquid silicone rubber was 1 part by weight. And the printing blanket was manufactured like Example 1 except having formed the porous layer using this mixture.

The thickness of the manufactured printing blanket at 154 points in the plane was measured in the same manner as described above, and the difference between the maximum value and the minimum value was determined to be 0.029 mm.
Next, the printing blanket was mounted on the blanket cylinder of the same printing machine used in Example 1. As the intaglio, a flat plate having a concave pattern with a depth of 5 μm and a line width of 20 μm was used. Then, in a state where ink is applied to the entire surface of the printing blanket, the surface of the printing blanket and the intaglio plate is transferred after the ink on the intaglio plate is rolled to transfer the ink in contact with the convex portions other than the concave pattern of the intaglio plate to the intaglio plate side. Was observed. As a result, the ink corresponding to the concave pattern of the intaglio is satisfactorily left on the surface of the printing blanket with a substantially uniform thickness, and the ink in contact with the convex parts other than the concave pattern is well transferred to the intaglio side. I was able to.

Example 3:
A liquid mixture for the porous layer was prepared in the same manner as in Example 1 except that the amount of hollow microspheres was 30 parts by weight with respect to 100 parts by weight of the liquid silicone rubber. And the printing blanket was manufactured like Example 1 except having formed the porous layer using this mixture.

The thickness of the manufactured printing blanket at 154 points in the plane was measured in the same manner as described above, and the difference between the maximum value and the minimum value was determined to be 0.034 mm.
Next, the printing blanket was mounted on the blanket cylinder of the same printing machine used in Example 1. As the intaglio, a flat plate having a concave pattern with a depth of 5 μm and a line width of 20 μm was used. Then, in a state where ink is applied to the entire surface of the printing blanket, the surface of the printing blanket and the intaglio plate is transferred after the ink on the intaglio plate is rolled to transfer the ink in contact with the convex portions other than the concave pattern of the intaglio plate to the intaglio plate side. Was observed. As a result, the ink corresponding to the concave pattern of the intaglio is satisfactorily left on the surface of the printing blanket with a substantially uniform thickness, and the ink in contact with the convex parts other than the concave pattern is well transferred to the intaglio side. I was able to.

Example 4:
A printing blanket was produced in the same manner as in Example 1 except that the fluororesin layer was not formed on the surface of the porous layer.
The thickness of the manufactured printing blanket at 154 points in the plane was measured in the same manner as described above, and the difference between the maximum value and the minimum value was determined to be 0.040 mm.

  Next, the printing blanket was mounted on the blanket cylinder of the same printing machine used in Example 1. As the intaglio, a flat plate having a concave pattern with a depth of 5 μm and a line width of 20 μm was used. Then, in a state where ink is applied to the entire surface of the printing blanket, the surface of the printing blanket and the intaglio plate is transferred after the ink on the intaglio plate is rolled to transfer the ink in contact with the convex portions other than the concave pattern of the intaglio plate to the intaglio side. Was observed. As a result, it was observed that the ink remaining on the surface of the printing blanket corresponding to the concave pattern of the intaglio was slightly uneven. From this, it has been found that when the fluororesin layer is not formed on the surface of the porous layer, the surface printed layer is uneven in thickness, although it is practically acceptable.

Comparative Example 1:
The same mixture for the porous layer as used in Example 1 was placed on a horizontal base provided with a large number of holes for suction, and sucked to adhere to the surface of the horizontal base. After coating with a bar coater on the exposed upper surface of a 30 mm polyethylene terephthalate (PET) film using a bar coater, it was allowed to stand at room temperature (23 ± 1 ° C.) for 24 hours to be liquid By curing the silicone rubber, a 0.7 mm thick porous layer was formed to produce an under blanket.

  In addition, the same mixture for the surface printed layer as used in Example 1 was prepared separately from the above, placed on a horizontal table provided with a number of holes for suction, and suctioned. After coating with a bar coater on the exposed upper surface of a 0.30 mm thick polyethylene terephthalate (PET) film adhered to the surface of the substrate at room temperature (23 ± 1 ° C.) For 24 hours to cure the liquid silicone rubber to form a non-porous surface printing layer having a thickness of 0.7 mm, and a printing blanket having a two-layer structure of a substrate and a surface printing layer. Manufactured.

The thickness of 154 points in the plane of the manufactured under blanket and printing blanket was measured in the same manner as described above, and when the difference between the maximum value and the minimum value was determined, the under blanket was 0.020 mm. The printing blanket was 0.015 mm.
Next, in the state which piled up the under blanket on the board | substrate side of the said printing blanket, it mounted | wore with the blanket cylinder of the same printing machine used in Example 1. FIG. As the intaglio, a flat plate having a concave pattern with a depth of 5 μm and a line width of 20 μm was used. Then, in a state where ink is applied to the entire surface of the printing blanket, the surface of the printing blanket and the intaglio plate is transferred after the ink on the intaglio plate is rolled to transfer the ink in contact with the convex portions other than the concave pattern of the intaglio plate to the intaglio plate side. Was observed. As a result, a part of the ink remaining on the surface of the printing blanket corresponding to the concave pattern of the intaglio was thinned, and a very small amount of ink was seen to adhere to the bottom of the concave of the intaglio. . From this, it was confirmed that in the configuration in which the under blanket was laminated under the printing blanket, a gap was generated between the two during the transfer, and the printing blanket was lifted up, so that good printing could not be performed.

Comparative Example 2:
The same mixture for the porous layer as used in Example 1 was placed on a horizontal base provided with a large number of holes for suction, and sucked to adhere to the surface of the horizontal base. After coating with a bar coater on the exposed upper surface of a 30 mm polyethylene terephthalate (PET) film using a bar coater, it was allowed to stand at room temperature (23 ± 1 ° C.) for 24 hours to be liquid By curing the silicone rubber, a 0.7 mm thick porous layer was formed.

  Next, while maintaining the state in which the base material is in close contact with the surface of the horizontal base, the same mixture for the surface printing layer as that used in Example 1 was continuously applied to the surface of the formed porous layer. After coating using a coater, the liquid silicone rubber is cured by standing at room temperature (23 ± 1 ° C.) for 24 hours to form a non-porous surface printed layer having a thickness of 0.7 mm. A printing blanket was produced.

The thickness of the manufactured printing blanket at 154 points in the plane was measured in the same manner as described above, and the difference between the maximum value and the minimum value was determined to be 0.032 mm.
Next, the printing blanket was mounted on the blanket cylinder of the same printing machine used in Example 1. As the intaglio, a flat plate having a concave pattern with a depth of 5 μm and a line width of 20 μm was used. Then, in a state where ink is applied to the entire surface of the printing blanket, the surface of the printing blanket and the intaglio plate is transferred after the ink on the intaglio plate is rolled to transfer the ink in contact with the convex portions other than the concave pattern of the intaglio plate to the intaglio plate side. Was observed. As a result, the ink left on the surface of the printing blanket corresponding to the concave pattern of the intaglio was thinned in many parts, and it was observed that the ink adhered to the bottom of the concave of the intaglio. . And from this, it was confirmed that when a porous layer is formed on one side of a substrate and a surface printing layer is laminated thereon, the surface printing layer becomes too soft to perform good printing. It was.

Comparative Example 3:
A liquid mixture for the porous layer was prepared in the same manner as in Example 1 except that the amount of the hollow microspheres relative to 100 parts by weight of the liquid silicone rubber was 0.5 parts by weight. And the printing blanket was manufactured like Example 1 except having formed the porous layer using this mixture.

The thickness of the manufactured printing blanket at 154 points in the plane was measured in the same manner as described above, and the difference between the maximum value and the minimum value was determined to be 0.029 mm.
Next, the printing blanket was mounted on the blanket cylinder of the same printing machine used in Example 1. As the intaglio, a flat plate having a concave pattern with a depth of 5 μm and a line width of 20 μm was used. Then, in a state where ink is applied to the entire surface of the printing blanket, the surface of the printing blanket and the intaglio plate is transferred after the ink on the intaglio plate is rolled to transfer the ink in contact with the convex portions other than the concave pattern of the intaglio plate to the intaglio plate side. Was observed. As a result, the ink remained on the surface of the printing blanket corresponding to the concave pattern of the intaglio was uneven, and the ink was observed to adhere to the bottom of the concave of the intaglio. And, from this, if the amount of hollow microspheres is too small, the flexibility of the porous layer is insufficient, and the printing blanket becomes too hard, so the subtle unevenness of the blanket affects the printing and is good. It was confirmed that printing was not possible.

Comparative Example 4:
A liquid mixture for the porous layer was prepared in the same manner as in Example 1 except that the amount of the hollow microspheres relative to 100 parts by weight of the liquid silicone rubber was 35 parts by weight. And the printing blanket was manufactured like Example 1 except having formed the porous layer using this mixture.

The thickness of the manufactured printing blanket at 154 points in the plane was measured in the same manner as described above, and the difference between the maximum value and the minimum value was determined to be 0.035 mm.
Next, the printing blanket was mounted on the blanket cylinder of the same printing machine used in Example 1. As the intaglio, a flat plate having a concave pattern with a depth of 5 μm and a line width of 20 μm was used. Then, in a state where ink is applied to the entire surface of the printing blanket, the surface of the printing blanket and the intaglio plate is transferred after the ink on the intaglio plate is rolled to transfer the ink in contact with the convex portions other than the concave pattern of the intaglio plate to the intaglio plate side. Was observed. As a result, the edge of the ink remaining on the surface of the printing blanket corresponding to the concave pattern of the intaglio was blurred blurry. From this, it was confirmed that if the amount of hollow microspheres is too large, the porous layer becomes too flexible and the printing blanket becomes too soft, so that good printing cannot be performed.

Comparative Example 5:
When forming the porous layer, a printing blanket was produced in the same manner as in Example 1 except that the horizontal table was inclined by 30 °.
The thickness at 154 points in the plane of the manufactured printing blanket was measured in the same manner as described above, and the difference between the maximum value and the minimum value was determined to be 0.101 mm.

  Next, the printing blanket was mounted on the blanket cylinder of the same printing machine used in Example 1. As the intaglio, a flat plate having a concave pattern with a depth of 5 μm and a line width of 20 μm was used. Then, in a state where ink is applied to the entire surface of the printing blanket, the surface of the printing blanket and the intaglio plate is transferred after the ink on the intaglio plate is rolled to transfer the ink in contact with the convex portions other than the concave pattern of the intaglio plate to the intaglio plate side. Was observed. As a result, the ink remained on the surface of the printing blanket corresponding to the concave pattern of the intaglio was uneven, and the ink was observed to adhere to the bottom of the concave of the intaglio. And from this, when the horizontal platform is tilted rather than horizontal, the thickness of the mixture becomes uneven due to the flow of the mixture, and the distribution of the hollow microspheres in the mixture also becomes uneven. It was confirmed that unevenness was caused in the thickness and internal structure of the quality layer, and in turn, the blanket, and good printing could not be performed.

Claims (5)

  A printing method in which ink is applied to the surface of the printing blanket and then brought into contact with the intaglio to transfer unnecessary ink to the intaglio and removed, and then the ink remaining on the surface is transferred to the surface of the printing medium. A method for producing a printing blanket having a porous layer on one side of a substrate and a surface printing layer on the opposite side, wherein 1 to 30 parts by weight of hollow microspheres are added to 100 parts by weight of liquid silicone rubber. A step of preparing a liquid mixture, and applying the mixture to one side of the base material, and while maintaining the base material horizontally, the liquid silicone rubber is cured to form a porous layer integrated with the base material. A method of manufacturing a printing blanket, comprising the step of forming.   The method for producing a printing blanket according to claim 1, wherein the liquid silicone rubber is cured at a temperature lower than the heat deformation temperature of the hollow microspheres to form a porous layer.   Liquid silicone rubber was applied to the surface of the substrate opposite to the side on which the porous layer was integrated, and the liquid silicone rubber was cured and integrated with the substrate while the substrate was held horizontally. The manufacturing method of the printing blanket of Claim 1 provided with the process of forming a surface printing layer.   The method for producing a printing blanket according to claim 3, wherein the liquid silicone rubber is cured at a temperature lower than the thermal deformation temperature of the hollow microspheres to form the surface printing layer. The method for producing a printing blanket according to claim 3, further comprising a step of forming a fluororesin layer on the surface of the porous layer prior to forming the surface printing layer on the opposite surface of the substrate.