Blanket roller and printing system

Abstract

Even if misalignment occurs between the plate cylinder and the blanket roller, the displacement is absorbed while maintaining a stable nip pressure between them. [Solution] The device comprises a cylindrical or columnar support (13), an elastic cushion layer (12) provided on the support (13), and an elastic printed layer (11) provided on the cushion layer (12). The printed layer (11) and the cushion layer (12) are configured to satisfy the relationships shown in the following equations (1) to (3). In the equations, E1 and E2 represent Young's modulus, and t1 and t2 represent thickness. E2 <E1 …(1) E1 = 2.0~2.5 [MPa] …(2) t1 / t2 ≤ 0.20 …(3)

Description

Technical Field

[0001] The present disclosure relates to, for example, a blanket roller (blanket cylinder) used in roll-to-roll (R2R) processes and reverse offset printing, and a printing system provided with the same.

Background Art

[0002] In general, anti-counterfeiting technologies such as optical technologies, physical technologies, electronic technologies, and even AI image recognition technologies are widely known. These are mainly applied to products and labels, and are intended to perform authenticity determination. However, these conventional techniques focus on the authentication of individual products, and have not functioned sufficiently as a method for monitoring the entire supply chain and ensuring the transparency of distribution channels.

[0003] Accordingly, the present applicant has developed and provided "Akliteia" (registered trademark), which combines anti-counterfeiting labels, authenticity determination devices, and blockchain technology, unlike such conventional techniques. In this system, highly accurate authenticity determination is enabled by using a transparent label printed with a special metal pattern of submicron resolution. This technology not only prevents the distribution of counterfeit products, but also realizes quantity management of genuine products. In addition, this system records the scan results of products on the blockchain and visualizes the occurrence status of counterfeit products in the entire supply chain, thereby making it easy to grasp the actual situation of damage.

[0004] For the production of such high-resolution metal pattern labels, a manufacturing process combining continuous processing using the roll-to-roll (R2R) method and high-definition pattern formation technology using reverse offset printing is effective. The R2R method is a process in which a fine pattern on a blanket roller is continuously transferred while a substrate such as film or metal foil is wound into a roll, and a seamless blanking roll (SBR) is preferably used as the blanket roller. On the other hand, in reverse offset printing, metal ink is first uniformly applied to the SBR by a slot die. Then, the negative pattern of a plate cylinder having a structure with fine irregularities (relief) on its surface (surface relief microstructure, SRM) is transferred to the coating film formed on the SBR (that part is removed). By finally transferring the coating film with the positive pattern thus formed to a substrate, a high-resolution metal pattern label can be obtained.

[0005] One known method for forming a coating film on a blanket roller such as an SBR involves bringing a slot die close to the rotating cylinder surface and dispensing a fixed amount of coating liquid from the tip of the slot die to continuously form a uniform liquid film on the blanket cylinder. In addition, SBRs generally employ a multilayer structure in which a cushion layer (foam layer) with predetermined elastic properties is attached to the outer circumference of a metal core to maintain high-precision alignment with the plate cylinder and impression cylinder during the printing process, while mitigating the mechanical shock generated when pressing with the plate cylinder. Furthermore, in order for the blanket roller to maintain a fine pattern structure and achieve high-precision pattern transfer to the substrate surface, a configuration in which a printing layer (transfer layer) made of a silicone rubber such as polydimethylsiloxane (PDMS) is laminated on the surface of the blanket roller is also widely used. For example, Patent Document 1 discloses a blanket relating to gravure offset printing technology in which an elastic material such as polyurethane is used as the foam layer, and a transfer layer such as silicone rubber is laminated on top of it. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 6053212 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, blanket rollers with a multilayer structure equipped with a cushion layer as described above have the problem that cylindricity and roundness are inevitably reduced compared to rollers with a metal core alone, due to the manufacturing process and material properties of the cushion layer (for example, the low dimensional stability inherent in foam). For example, when urethane rubber is used for the cushion layer, roll runout of approximately ±20 μm (runout width of 40 μm) may occur when the blanket roller rotates. This raises concerns about significant misalignment between the plate cylinder and the blanket roller. This misalignment causes the linear pressure at the nip point (hereinafter referred to as "nip pressure"), which is the contact point between the plate cylinder and the blanket roller (printing layer), to fluctuate significantly within the printing surface. As a result, the SRM formed by the plate cylinder cannot be transferred with high precision to the coating film formed on the printing layer of the blanket roller, and ultimately, it may become difficult to form a metal pattern with the desired resolution on the substrate.

[0008] On the other hand, while the blanket roller described in Patent Document 1 can maintain the transfer pattern shape to some extent by adjusting the Shore hardness and thickness of the foam layer and the printing layer, it does not fundamentally eliminate the significant misalignment that occurs between the plate cylinder and the blanket roller as described above.

[0009] Therefore, this disclosure has been made in view of these circumstances, and aims to provide a blanket roller and a printing system that can stably maintain the nip pressure between the plate cylinder and the blanket roller while absorbing the displacement, even when a misalignment occurs between the plate cylinder and the blanket roller in, for example, R2R reverse offset printing. [Means for solving the problem]

[0010] [1] To achieve the above objective, the blanket roller according to this disclosure comprises a cylindrical or columnar support, an elastic cushion layer provided on the support, and an elastic printed layer provided on the cushion layer. The printed layer and the cushion layer are configured to satisfy the relationships shown in the following formulas (1) to (3). In the formulas, E1 and E2 represent the Young's modulus of the printed layer and the cushion layer, respectively, and t1 and t2 represent the thickness of the printed layer and the cushion layer, respectively. E2 <E1 …(1) E1 = 2.0~2.5 [MPa] …(2) t1 / t2 ≤ 0.20 …(3)

[0011] With this configuration, the blanket roller satisfies equation (1), resulting in a higher rigidity of the printed layer compared to the cushion layer. Even under the same applied load, the printed layer is less susceptible to deformation (compression) than the cushion layer. On the other hand, the cushion layer is more easily deformed than the printed layer. Furthermore, the specific rigidity of the printed layer is preferably within the range shown in equation (2). Moreover, by satisfying equation (3), the printed layer is moderately compressed, optimizing the reduction in thickness Δt1 of the printed layer while maximizing the reduction in thickness Δt2 of the cushion layer. As a result, even if misalignment occurs between the plate cylinder and the blanket roller, the displacement is effectively absorbed, and the nip (contact) pressure between the two is stably maintained. This allows for high-precision transfer of the SRM pattern on the plate cylinder to the coating on the blanket roller, ultimately enabling the formation of a high-resolution and high-quality metal pattern on the substrate.

[0012] [2] In the above configuration, the printed layer and the cushion layer may be configured to further satisfy the relationship shown in the following formula (4). t1 + t2 ≥ 10.0 [mm] …(4) With this configuration, even if the roll runout (runout) amount becomes relatively large, around ±20 μm (runout amplitude 40 μm), when the blanket roller rotates, it is possible to effectively absorb the displacement and stably maintain the nip pressure.

[0013] [3] Alternatively, in the above configuration, the printed layer and the cushion layer may be configured to further satisfy the relationship shown in formula (5) below. E1 / E2≧1.5 …(5) This further promotes minimizing the thickness change Δt1 of the printed layer and maximizing the thickness change Δt2 of the cushion layer, resulting in even greater stabilization of the nip pressure.

[0014] [4] In the above configuration, the blanket roller may be configured to further satisfy the relationship shown in the following formula (6). In the formula, C represents the cylindricity of the blanket roller. C = 1 to 20 [μm] …(6) Here, "cylindricity" in this disclosure refers to a value obtained by a measurement method in accordance with the provisions of "JIS B 0021: Geometric tolerances - Tolerances for shape, orientation, position and runout". By configuring it in this way, it becomes possible to bring the surface of the blanket roller closer to an ideal cylindrical surface, and as a result, unevenness in the film thickness of the coating applied to SBR1 can be effectively suppressed, and higher quality printing can be achieved.

[0015] [5] The blanket roller may also be configured to further satisfy the relationship shown in the following formula (7). In the formula, Rz represents the surface roughness of the printed layer, excluding Rz=0. Rz ≤ 1.6 [μm] …(7) Here, generally, the printed layer, which is the outermost layer of the blanket roller, is formed by surrounding a precursor with a cushion layer formed on a support with a mold, filling and curing the uncured printed layer material between the mold and the precursor, and then demolding. Therefore, the "surface roughness" in this disclosure is assumed to be the surface roughness of the inner circumferential surface of the mold, and is replaced by the surface roughness of the inner circumferential surface of the mold obtained by a measurement method compliant with the provisions of "JIS B 0601: Geometric product specifications (GPS) - Surface roughness: Contour method - Surface roughness parameters".

[0016] In this case, the surface roughness of the inner circumferential surface of the mold may cause streaky irregularities (streaky defects) to occur on the surface of the printed layer. Furthermore, these streaky irregularities may be transferred to the coating on the printed layer, and ultimately streaky irregularities may also occur in the positive pattern on the substrate. In contrast, by mirror polishing the inner circumferential surface of the mold (a combination of mechanical polishing and electrolytic polishing, for example), the surface roughness of the printed layer can be brought within the range of equation (7). As a result, it becomes possible to effectively suppress the occurrence of streaky irregularities in the coating on the printed layer and in the positive pattern that is ultimately transferred to the substrate.

[0017] [6] More specifically, the printed layer preferably has a seamless, continuous surface.

[0018] [7-9] The printed layer may contain, for example, a polymer (silicone) having siloxane bonds, and silicone rubber, which is an elastomer thereof, is particularly preferred. Among these, polydimethylsiloxane (PDMS) or its elastomer is even more preferred. Furthermore, the cushion layer may contain, for example, a polymer (polyurethane) having urethane bonds, and urethane rubber, which is an elastomer thereof, is particularly preferred. In addition, the support may be made of, for example, metal. By adopting such a material configuration, the rotational drive of the blanket roller can be stabilized, and optimization can be easily achieved by minimizing the thickness change amount Δt1 of the printed layer and maximizing the thickness change amount Δt2 of the cushion layer.

[0019]

[10] Further, a printing system according to the present disclosure includes: a blanket roller according to the present disclosure; a slot die disposed in proximity to the blanket roller; and a plate cylinder and an impression cylinder disposed to face the blanket roller so as to sandwich the slot die in the rotation direction of the blanket roller. The slot die continuously forms a coating film (liquid film) of a coating liquid on the surface of the rotating blanket roller. The plate cylinder has a negative pattern, and removes a portion corresponding to the negative pattern from the coating film on the surface of the blanket roller to form a positive pattern, and the blanket roller transfers the positive pattern onto a base material being conveyed on the surface of the impression cylinder. [Brief Description of the Drawings]

[0020] [Figure 1] FIG. 2 is a schematic diagram schematically illustrating the configuration (partial process flow) of a printing system 100 including SBR 1 according to an embodiment of the present disclosure. [Figure 2] FIG. 2 shows an example of a cross section perpendicular to the extension axis Ax of SBR 1 shown in FIG. 1, and is a cross-sectional view taken along line II-II in FIG. 3(B). [Figure 3] (A) is a side view (plan view viewed in the direction of the extension axis Ax) of SBR 1 shown in FIG. 1, and (B) is a front view thereof. [Figure 4] (A) is a schematic plan view enlarging part A enclosed by the one-dot chain line in FIG. 1 and showing a state where SRM is transferred to the coating film 50, and (B) is a schematic plan view enlarging part B enclosed by the one-dot chain line in FIG. 1 and showing a state where the positive pattern 50p is transferred to the film 7. [Figure 5] (A) and (B) are schematic enlarged views of part C enclosed by the one-dot chain line in FIG. 2, and (B) schematically shows a state where an external force σ (nip pressure) is applied from the state shown in (A). [Figure 6] FIG. 4 is a graph (scatter diagram) showing the relationship between nip pressure uniformity and Young's modulus ratio E1 / E2 obtained in Evaluation Example 1. [Figure 7] FIG. 5 is a graph (scatter diagram) showing the relationship between nip pressure uniformity and thickness ratio t1 / t2 obtained in Evaluation Example 2. [Figure 8] This graph (scatter plot) shows the relationship between the nip pressure uniformity and the overall thickness t1+t2 obtained in Evaluation Example 2. [Modes for carrying out the invention]

[0021] This embodiment will be described below with reference to the attached drawings. To facilitate understanding of the description, the same reference numerals are used for identical components in each drawing whenever possible, and redundant descriptions are omitted. The following embodiments are illustrative examples for illustrating the present disclosure and are not intended to limit the present disclosure to these embodiments only. Furthermore, the present disclosure can be modified in various ways without departing from its essence. Moreover, those skilled in the art can adopt embodiments in which each of the elements described below is replaced with equivalent components, and such embodiments are also included within the scope of the present disclosure.

[0022] Figure 1 is a schematic diagram illustrating the configuration (and part of the process flow) of a printing system 100 equipped with an SBR1 according to one embodiment of the present disclosure. The printing system 100 is a system that produces a transparent label 7' by printing a special metallic pattern, for example, for anti-counterfeiting purposes, on a film 7 (corresponding to an example of a "substrate" in the present disclosure). To achieve this, the printing system 100 employs R2R (roll-to-roll) reverse offset printing. The film 7 is held between an unwinding roll R1 and a take-up roll R2, and is configured to be transported in the direction of the arrow X shown in the figure, via a plurality of rollers G11 to G16, while appropriate tension is applied and its direction is adjusted.

[0023] The printing system 100 comprises a cylindrical seamless blanket cylinder 1 (SBR: corresponding to an example of a "blanket roller" in this disclosure), a slot die 2, and cylindrical or cylindrical plate cylinders 3 and impression cylinder 4. The slot die 2 is positioned close to the SBR 1, and the plate cylinders 3 and impression cylinder 4 are positioned opposite the SBR 1, sandwiching the slot die 2 in the rotation direction Y1 (clockwise) of the SBR 1. In the printing system 100, a drying and curing device 9 is installed between the impression cylinder 4 and the take-up roll R2 for drying and curing the coating film 50 (and its positive pattern 50p) that has been final transferred onto the film 7.

[0024] Figure 2 shows an example of a cross-section perpendicular to the extension axis Ax (longitudinal axis, central axis) of the SBR1 shown in Figure 1. Figure 3(A) is a side view (plan view as seen in the direction of the extension axis Ax) of the SBR1 shown in Figure 1, and Figure 3(B) is a front view thereof. As shown in these figures, the SBR1 has a cylindrical or columnar support 13 at its center, with a cushion layer 12 having appropriate elasticity around it, and a printed layer 11 having appropriate elasticity laminated and coated on its surface. The printed layer 11 has a seamless surface. Furthermore, a shaft 14 for holding and rotating the SBR1 from both ends is provided protruding from the center of the end face of the support 13. This shaft 14 may be provided as a single rod-shaped member passing through the support 13, or as two rod-shaped members fixed or embedded in the end face of the support 13.

[0025] In addition, the printed layer 11 can contain, for example, a polymer (silicone) having siloxane bonds, and silicone rubber, which is an elastomer thereof, is particularly preferred. Among these, polydimethylsiloxane (PDMS) or its elastomer is even more preferred. Furthermore, the cushion layer 12 can contain, for example, a polymer (polyurethane) having urethane bonds, and urethane rubber, which is an elastomer thereof, is particularly preferred. Also, a metal core such as iron is preferred as the support 13. By adopting such a material configuration, the stability of the SBR1 during rotational drive is enhanced, and optimization is easily achieved by minimizing the thickness change amount Δt1 of the printed layer 11 and maximizing the thickness change amount Δt2 of the cushion layer 12.

[0026] Returning to Figure 1, the main body 20 of the slot die 2 is connected to a storage tank 5T via piping equipped with a precision metering pump Pm1. By operating the precision metering pump Pm1, the coating liquid 5 is accurately metered in a predetermined amount and continuously supplied to the inside of the main body 20 of the slot die 2. The coating liquid 5 is, for example, a thermosetting or photocurable resin composition containing copper (metallic copper or copper compound) as an element, and a fine pattern of copper or copper compound is formed on the film 7.

[0027] Furthermore, the slot die 2 discharges the coating liquid 5 from the tip of the main body 20 facing the SBR 1 toward the SBR 1, thereby forming a bead (not shown) of the coating liquid 5 between it and the SBR 1. At the same time, the slot die 2 uses a vacuum pump Pm2 to suck in the atmosphere behind the tip and performs a vacuum treatment. In addition, a cover portion 22 is provided to cover or surround the atmosphere in order to enhance the vacuum effect at that time.

[0028] As described above, coating liquid 5 is continuously supplied from the slot die 2, and as the SBR 1 rotates, the coating liquid 5 is uniformly applied to the surface of the printing layer 11 of the SBR 1, forming a coating film 50 of a constant thickness. This coating film 50 reaches the plate cylinder 3 opposite the SBR 1, and since the plate cylinder 3 is driven in the rotation direction Y2 (counterclockwise), the surface relief microstructure (SRM) formed on the plate cylinder 3 is transferred to the coating film 50. Figure 4(A) is a schematic plan view showing an enlarged view of section A enclosed by a dashed line in Figure 1, illustrating the state in which the SRM is transferred to the coating film 50. As shown in the figure, the negative pattern 3n of the SRM formed on the plate cylinder 3 is pressed against the coating film 50 on the SBR 1, and the corresponding portion is extracted as the negative pattern 50n of the coating film 50. As a result, a positive pattern 50p is formed on the coating film 50 after passing through the plate cylinder 3. Furthermore, the negative pattern 50n that has been removed and held in the plate cylinder 3 is transferred to another film 8 that is fed out from the unwinding roll R3 and changed direction by roller G3, and then recovered by the take-up roll R4 (Figure 1).

[0029] Furthermore, as the SBR1 rotates, the coating film 50 having the positive pattern 50p is positioned opposite the SBR1 and reaches the impression cylinder 4, which is driven in the rotation direction Y3 (counterclockwise). At this point, the positive pattern 50p is finally transferred to the film 7 unwound from the unwinding roll R1. Figure 4(B) is a schematic plan view showing the state in which the positive pattern 50p has been transferred to the film 7, enlarged from section B enclosed by a dashed line in Figure 1. As shown in the figure, the positive pattern 50p of the coating film 50 formed on the printing layer 11 of the SBR1 is pressed against the film 7 on the impression cylinder 4, and that portion is transferred onto the film 7. Subsequently, the film 7 having this positive pattern 50p passes through the drying and curing device 9 to obtain a transparent label 7' with a metallic pattern printed on it, which is then wound onto the winding roll R2.

[0030] Figures 5(A) and (B) are schematic enlarged views of section C, which is enclosed by a dashed line in Figure 2. Figure 5(B) schematically shows the state in which an external force σ (nip pressure) is applied from the state shown in (A). For example, when SBR1 and plate cylinder 3 are in contact, if displacement occurs due to vibration of SBR1 or tilt occurs between the central axes of both, the printing layer 11 and cushion layer 12 of SBR1 are compressed to absorb the impact. In the example shown in Figure 5, the initial thicknesses t1 and t2 of the printing layer 11 and cushion layer 12 are compressed to final thicknesses t1-Δt1 and t2-Δt2, respectively. In this disclosure, even in such cases, the aim is to maintain a constant nip pressure when SBR1 and plate cylinder 3 are in contact, by absorbing the applied pressure as much as possible with the cushion layer 12, while suppressing changes in the thickness of the printing layer 11 as much as possible. Therefore, SBR1 employs a configuration that minimizes the thickness change Δt1 of the printed layer 11 and maximizes the thickness change Δt2 of the cushion layer 12.

[0031] Specifically, the printed layer 11 and the cushion layer 12 (blanket portion) are configured to satisfy the relationships shown in equations (1) to (3) below. In these equations, E1 and E2 represent the Young's moduli of the printed layer 11 and the cushion layer 12, respectively, and t1 and t2 represent the thicknesses of the printed layer 11 and the cushion layer 12, respectively. E2 <E1 …(1) E1 = 2.0~2.5 [MPa] …(2) t1 / t2 ≤ 0.20 …(3)

[0032] As SBR1 satisfies equation (1), the printing layer 11 has higher rigidity than the cushion layer 12, and even when the same load is applied, the printing layer 11 is less likely to deform (compress) than the cushion layer 12. On the other hand, the cushion layer 12 has the characteristic of being more easily deformed than the printing layer 11. In addition, as SBR1 satisfies equations (2) and (3), the printing layer 11 is compressed appropriately, optimizing the reduction in thickness Δt1 of the printing layer 11 while maximizing the reduction in thickness Δt2 of the cushion layer 12. As a result, even if a misalignment occurs between the plate cylinder 3 and SBR1, it is possible to effectively absorb the displacement and stably maintain the nip (contact) pressure between the two. This makes it possible to transfer the SRM pattern on the plate cylinder 3 to the coating 50 on SBR1 with high precision, and ultimately, to form a high-resolution and high-quality metal pattern on the substrate 7.

[0033] Furthermore, the printed layer 11 and the cushion layer 12 (blanket portion) may satisfy the relationship shown in the following formula (4) and / or formula (5). t1 + t2 ≥ 10.0 [mm] …(4) E1 / E2≧1.5 …(5)

[0034] By configuring the system to satisfy the relationship in equation (4) above, even when the roll runout amount becomes relatively large, around 20 μm, during the rotation of the SBR1, the displacement can be effectively absorbed, and the nip pressure can be stably maintained. Furthermore, by satisfying the relationship in equation (5), the minimization of the thickness change amount Δt1 of the printed layer 11 and the maximization of the thickness change amount Δt2 of the cushion layer 12 are further promoted, and as a result, the stability of the nip pressure can be further enhanced.

[0035] Furthermore, the cylindricity C of SBR1 may satisfy the relationship shown in equation (6) below. C = 1 to 20 [μm] …(6) By configuring the system to satisfy the relationship in equation (6) above, it becomes possible to bring the surface of SBR1 closer to an ideal cylindrical surface. As a result, unevenness in the film thickness of the coating 50 applied to SBR1 can be effectively suppressed, and higher quality printing can be achieved.

[0036] Furthermore, it is also preferable that the surface roughness Rz of the printed layer 11 satisfies the relationship shown in the following formula (7). Rz ≤ 1.6 [μm] …(7) Generally, the printed layer 11, which is the outermost layer of SBR1, is formed by surrounding a precursor with a cushion layer 12 formed on a support 13 with a mold, filling and curing the uncured printed layer 11 material between the mold and the precursor, and then demolding. In this process, the surface roughness of the inner circumferential surface of the mold may cause streaky irregularities (streaky defects) to occur on the surface of the printed layer 11. Furthermore, these streaky irregularities may be transferred to the coating film 50 on the printed layer 11, and ultimately streaky irregularities may occur in the positive pattern 50p on the substrate. In contrast, by mirror polishing the inner circumferential surface of the mold (a combination of mechanical polishing and electrolytic polishing, etc.), the surface roughness of the printed layer 11 can be brought within the range of equation (7). As a result, it becomes possible to effectively suppress the occurrence of streaky irregularities in the coating film 50 on the cushion layer 12 and in the positive pattern 50p that is finally transferred onto the film 7.

[0037] [Evaluation Example 1] Based on the configurations of SBR1 and plate cylinder 3 shown in Figures 1 to 5, an analysis and evaluation model using the finite element method (FEM) was constructed, and structural analysis, particularly of compression behavior, was performed. The geometric conditions, material conditions, and main analysis conditions in the analysis and evaluation model are as follows. (SBR1) ·Cross-sectional diameter DR:300[mm] Body width DL: 250 [mm] • Material of printing layer 11: PDMS • Material of cushion layer 12: Urethane rubber (Placement of SBR1 and cylinder 3) • Roll runout: 20 [μm] Relative tilt: 20 [μm] / 250 [mm] = 0.0005 [°]

[0038] The Young's modulus and thickness of the printed layer 11 and the cushion layer 12 were set as shown in Table 1, and the nip pressure uniformity was evaluated. As shown in Table 1, in this evaluation example 1, the conditions of the printed layer 11 were fixed, and the effect on the nip pressure uniformity when the Young's modulus ratio E1 / E2 was varied by changing the Young's modulus of the cushion layer 12 was analyzed and evaluated. "Nip pressure uniformity" is quantified as the difference between the maximum and minimum values ​​of the nip pressure applied to SBR1 (nip pressure difference ΔP [MPa]), and the smaller this value, the higher the nip pressure uniformity.

[0039] [Table 1]

[0040] Figure 6 is a scatter plot showing the relationship between the nip pressure difference ΔP and the Young's modulus ratio E1 / E2 obtained in Evaluation Example 1. In this figure, cases where the nip pressure difference ΔP was 10 [MPa] or less are indicated by black circles (●) as data with relatively high nip pressure uniformity, and data where the nip pressure difference ΔP exceeded 10 [MPa] are indicated by × marks. In addition, the guideline for these data is shown by a dashed line. From these results, it was confirmed that if the Young's modulus ratio E1 / E2 of the printed layer 11 and the cushion layer 12 is in the range of 1.5 or higher (Equation (5)), high nip pressure uniformity can be maintained.

[0041] [Evaluation Example 2] Using the same analytical evaluation model as in Evaluation Example 1, the Young's modulus and thickness of the printed layer 11 and the cushion layer 12 were set as shown in Table 2, and the uniformity of the nip pressure was evaluated. As shown in Table 2, in this Evaluation Example 2, while the conditions of the printed layer 11 were fixed, the effect on the uniformity of the nip pressure when the thickness ratio t1 / t2 and the total thickness t1+t2 were varied by changing the thickness of the cushion layer 12 was analyzed and evaluated (Case 1 is the same as in Evaluation Example 1).

[0042] [Table 2]

[0043] Figure 7 is a scatter plot graph showing the relationship between the nip pressure difference ΔP and the thickness ratio t1 / t2 obtained in Evaluation Example 2. In this figure, cases where the nip pressure difference ΔP was 10 [MPa] or less are indicated by black circles (●) as data with relatively high nip pressure uniformity, and data where the nip pressure difference ΔP exceeded 10 [MPa] are indicated by × marks. In addition, the guideline for these data is shown by dashed lines. From these results, it was confirmed that high nip pressure uniformity can be maintained if the thickness ratio t1 / t2 of the printed layer 11 and the cushion layer 12 is in the range of 0.20 or less (Equation (3)).

[0044] Figure 8 is a scatter plot showing the relationship between the nip pressure difference ΔP and the total thickness t1+t2 obtained in Evaluation Example 2. In this figure, cases where the nip pressure difference ΔP was 10 [MPa] or less are indicated by black circles (●) as data with relatively high nip pressure uniformity, and data where the nip pressure difference ΔP exceeded 10 [MPa] are indicated by × marks. In addition, the guideline for these data is shown by dashed lines. From these results, it was confirmed that if the total thickness t1+t2 of the printed layer 11 and the cushion layer 12 is 10.0 or more (Equation (4)), high nip pressure uniformity can be maintained.

[0045] [Evaluation Example 3] Based on the configurations shown in Figures 1 to 5, multiple prototypes of SBR1 with different cylindricity C were fabricated, and the film thickness variations when a coating 50 was formed on these SBR1s were measured and evaluated. The geometric and material conditions of SBR1 are as follows. (SBR1) ·Cross-sectional diameter DR:300[mm] Body width DL: 250 [mm] • Material of printing layer 11: PDMS • Thickness of printed layer 11: t1: 1.5 [mm] • Material of cushion layer 12: Urethane rubber • Thickness of cushion layer 12: t2: 10 [mm] ·Cylindricity C: 18[μm], 55[μm]

[0046] Film thickness unevenness is expressed as a percentage [%] when the film thickness of coating 50 is measured at three representative points in the TD direction (body width direction, transverse direction) of SBR1, and the maximum variation range, taking into account the errors of these measurements, is divided by the average film thickness of these three points. As a result, for SBR1 with a cylindricity C of 18 [μm], the average film thickness was 360 [nm], the maximum variation range was 27 [nm], and the film thickness unevenness was 7.5 [%]. On the other hand, for SBR1 with a cylindricity C of 55 [μm], the average film thickness was 308 [nm], the maximum variation range was 90 [nm], and the film thickness unevenness was 29.2 [%]. From these results, the advantage of setting the cylindricity C of SBR1 in the range of 1 to 20 [μm] (Equation (6)) was confirmed.

[0047] [Evaluation Example 4] Based on the configurations shown in Figures 1 to 5, multiple prototypes of SBR1 with different surface roughness Rz of the printed layer 11 were fabricated. After coating these SBR1 with a coating 50 and forming a film, the occurrence of streak-like defects and other defects was evaluated from captured images. The geometric and material conditions of SBR1 are as follows. (SBR1) ·Cross-sectional diameter DR:300[mm] Body width DL: 250 [mm] • Material of printing layer 11: PDMS • Thickness of printed layer 11: t1: 1.5 [mm] • Material of cushion layer 12: Urethane rubber • Thickness of cushion layer 12: t2: 10 [mm] • Surface roughness Rz of printed layer 11: 0.9 [μm], 7.1 [μm]

[0048] As a result, in SBR1 with a surface roughness Rz of 7.1 [μm] in the printed layer 11, the number of defects per unit area was 242 [defects / m²]. 2 ] and contained many streaky defects. In contrast, SBR1 with a surface roughness Rz of 0.9 [μm] in the printed layer 11 had 18 defects per unit area [ / m²]. 2 ] and no streaky defects were found at all. From this, the advantage of setting the surface roughness Rz of the printed layer 11 of SBR1 to 1.6 [μm] or less (Equation (7)) can be understood.

[0049] The embodiments described above with reference to specific examples are provided to facilitate understanding of this disclosure and are not intended to limit its interpretation. In other words, this disclosure is not limited to these specific examples, and modifications made to these examples by those skilled in the art are also included within the technical scope of this disclosure, as long as they retain the features of this disclosure. Furthermore, the elements, arrangements, materials, conditions, shapes, dimensions, scales, etc., of each of the aforementioned specific examples are not limited to those exemplified unless otherwise specified and can be modified as appropriate. Moreover, the elements of each of the aforementioned specific examples can be combined in different ways as appropriate, as long as no technical inconsistencies arise. [Explanation of Symbols]

[0050] 1…Seamless blanket cylinder (SBR, blanket cylinder, blanket roller), 2…Slot die, 3…Plate cylinder, 3n…Negative pattern, 4…Impact cylinder, 5…Coating liquid, 5T…Storage tank, 7…Film (substrate), 7'…Transparent label, 8…Film, 9…Drying and curing device, 11…Printing layer, 12…Cushion layer, 13…Support, 14…Shaft, 20…Main body, 22…Cover part, 50n…Negative pattern, 50p…Positive pattern, 100…Printing system, Ax…Extension axis, DL…Cylinder width, DR…Cross-sectional diameter, G3, G11~G16…Rollers, Pm1…Precision metering pump, Pm2…Depressurization pump, R1, R3…Unwinding roll, R2, R4…Take-up roll, X…Arrow, Y1, Y2, Y3…Rotation direction, σ…External force

Claims

1. A cylindrical or columnar support, An elastic cushion layer provided on the support, An elastic printed layer provided on the cushion layer, Equipped with, The printing layer and the cushion layer are defined by the following formulas (1) to (3): E2<E1...(1), E1=2.0 to 2.5 [MPa]...(2), t1 / t2≦0.20…(3), Here, E1 and E2 represent the Young's moduli of the printing layer and the cushion layer, respectively, and t1 and t2 represent the thicknesses of the printing layer and the cushion layer, respectively. A blanket roller that satisfies the relationship shown.

2. The printed layer and the cushion layer are defined by the following formula (4): t1+t2≧10.0[mm]…(4), A blanket roller according to claim 1 that satisfies the relationship shown.

3. The printing layer and the cushion layer are defined by the following formula (5): E1 / E2≧1.5…(5), A blanket roller according to claim 1 or 2 that satisfies the relationship shown.

4. The blanket roller is as follows: (6) C=1 to 20 [μm]...(6), Here, C indicates the cylindricity of the blanket roller. A blanket roller according to claim 1 or 2 that satisfies the relationship shown.

5. The blanket roller is as follows: (7) Rz≦1.6 [μm]…(7), Here, Rz represents the surface roughness of the printed layer, excluding Rz = 0. The blanket roller according to claim 1 or 2, further satisfying the relationship shown.

6. The blanket roller according to claim 1 or 2, wherein the printed layer has a seamless, continuous surface.

7. The blanket roller according to claim 1 or 2, wherein the printed layer comprises a polymer having siloxane bonds.

8. The blanket roller according to claim 1 or 2, wherein the cushion layer comprises a polymer having urethane bonds.

9. The blanket roller according to claim 1 or 2, wherein the support is made of metal.

10. A blanket roller according to claim 1 or 2, A slot die positioned in close proximity to the blanket roller, A plate cylinder and an impression cylinder are positioned opposite the blanket roller so as to sandwich the slot die in the rotational direction of the blanket roller, Equipped with, The slot die continuously forms a coating film of the coating liquid on the surface of the rotating blanket roller. The plate cylinder has a negative pattern, and a positive pattern is formed by removing a portion corresponding to the negative pattern from the coating film on the surface of the blanket roller. The blanket roller transfers the positive pattern onto the substrate being transported on the surface of the impression cylinder. Printing system.

Images