JP2017024303A - Printing blanket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing blanket which generates no stain of a printed matter by transcription of an ink or a paper powder accumulated in a groove of a plate cylinder, can stably achieve stain prevention effect of the printed matter over long time and generates no image disturbance (shock streak) even when printed at high speed.SOLUTION: There is provided a flat sheet-like printing blanket having a base fabric layer 10 manufactured by laminating a plurality of woven fabrics and a surface rubber layer 40 and equipped to a blanket cylinder of a double-size transfer cylinder type printer, where a cured coated film 60 with a condensation curable silicone-based coating material having hydrogen bond component of surface tension (γ) of 0.7 mN/m or more is formed on a flat surface (band-like area) of the surface rubber layer by contacting with the groove of the plate cylinder during printing by the double-size transfer cylinder type printer.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a printing blanket mounted on a blanket cylinder of a double cylinder type offset printing machine.

  Conventionally, as an offset printing machine, a double cylinder type printing machine in which the diameter of the blanket cylinder is twice the diameter of the plate cylinder is known.

  However, in the double cylinder type offset printing press, since the plate cylinder rotates twice while the blanket cylinder rotates once, a blanket groove (gap) for mounting the blanket and a printing plate are mounted. Even if printing is started by aligning so that the groove (gap) of the plate cylinder coincides, when the plate cylinder rotates once, the groove of the plate cylinder is opposite to the groove position of the blanket cylinder. In contact with the surface of the blanket at the position (circumferential position with an interval of 180 °), ink and paper dust deposited in the groove of the plate cylinder are received by the surface of the blanket and transferred to printed matter (paper). Therefore, there is a problem that the printed matter is soiled.

  As means for solving such a problem, the following Patent Document 1 introduces the formation of a recess on the surface of a blanket that comes into contact with a groove (gap) of a plate cylinder. Further, in Patent Document 2 below, a recess is formed on the surface of a blanket that comes into contact with a groove (gap) of the plate cylinder, and the affinity for ink is low on the surface of the recess while maintaining the shape of the recess. It has been introduced that a coating film is formed, and a coating film made of silicone rubber, silicone resin, fluororubber, or fluororesin is described.

JP 2010-167616 A JP 2000-6543 A

  However, when manufacturing the blanket described in Patent Document 1 and Patent Document 2, the processing operation for forming the recess is complicated.

  Further, when the blanket described in Patent Document 1 and Patent Document 2 is mounted on the blanket cylinder and offset printing is performed, the pressure applied to the blanket surface is suddenly relieved in the concave portion, and image disturbance ( There is a problem that shock eyes) occur. Such image disturbance can be prevented to some extent by printing at low speed, but this is not preferable because it causes a decrease in printing efficiency.

  For such a problem, without forming a recess in the surface of the blanket that will come into contact with the groove of the plate cylinder, the surface (flat surface) is coated with ink as described in Patent Document 2. It is conceivable to form a coating film having a low affinity.

However, the present inventors have confirmed that various coating films having low affinity with ink have poor adhesion to the surface of the blanket (surface rubber layer) and peel off during printing. It was a thing.
Further, the effect of suppressing ink acceptance was insufficient, and the printed matter was still stained. In particular, the fluorine-based coating film, which has a low affinity with ink in Patent Document 2, has a large tendency to accept ink.

The present invention has been made based on the above situation.
The object of the present invention is to stably exhibit such anti-smudge effect of printed matter for a long period of time without causing stain of the printed matter due to transfer of ink or paper dust deposited in the groove (gap) of the plate cylinder. It is an object of the present invention to provide a printing blanket that does not cause image distortion (shock eyes) or the like even when printing at high speed.

The printing blanket of the present invention comprises a base fabric layer formed by laminating a plurality of woven fabrics and a surface rubber layer, and is a flat printing blanket mounted on a blanket cylinder of a double cylinder type printing press. There,
A hydrogen bond component (γ _s ^h ) of the surface tension is 0.7 mN on the flat surface (band-like region) of the surface rubber layer that comes into contact with the groove of the plate cylinder during printing by the double cylinder type printing press. It is characterized in that a cured film is formed of a condensation-curing type silicone-based coating material of at least / m.

According to the printing blanket having such a configuration, the cured coating formed on the surface rubber layer is a silicone-based coating having a surface tension hydrogen bond component (γ _s ^h ) of 0.7 mN / m or more. As a result, the cured film exhibits excellent ink repellency, and as a result, almost no ink or paper dust is accepted at the portion of the blanket surface where the cured film is formed, and as a result, the printed matter is reliably prevented from being stained. be able to.

  Moreover, since the cured film formed on the surface rubber layer is a cured film of a “condensation-curable” silicone-based coating material, the cured film has high adhesion to the surface rubber layer and excellent durability. Yes. Thereby, the stain prevention effect of printed matter can be stably exhibited over a long period of time.

  In addition, since the cured coating is formed on the flat surface of the surface rubber layer, the pressure applied to the blanket surface is not suddenly relieved at the portion where the cured coating is formed, so printing is performed at high speed. However, it does not cause image disturbance (shock eyes).

In the printing blanket of the present invention, the hydrogen bond component (γ _s ^h ) of the surface tension of the cured film is preferably 1.0 mN / m or more, particularly 1.1 mN / m or more.

  In the printing blanket of the present invention, it is preferable that the thickness of the cured film is 5 to 100 μm.

  Further, the raw rubber constituting the surface rubber layer is preferably nitrile rubber (NBR).

  According to the printing blanket of the present invention, the printed matter is not smudged due to the transfer of ink or paper dust accumulated in the groove (gap) of the plate cylinder, and the effect of preventing such stain on the printed matter is stable over a long period of time. The image is not disturbed (shock eyes) even when printed at high speed.

It is a top view which shows one Embodiment of the printing blanket of this invention. It is II-II sectional drawing of the printing blanket shown in FIG. (1) is a plan view showing the size of a blanket subjected to an ink transfer test and a film formation region, and (2) is a plan view showing a blanket size and a film formation region subjected to a durability test of the film. . (1) is a schematic diagram showing a schematic configuration of the testing machine used for the ink transfer test (cylinder arrangement), and (2) is a schematic configuration of the testing machine used for the durability test of the coating (cylinder arrangement). It is a schematic diagram which shows. 2 is a photograph showing a test result of an ink transfer test in the blanket obtained in Example 1. FIG.

Hereinafter, the printing blanket of the present invention will be described in detail.
A blanket 100 shown in FIGS. 1 and 2 includes a base fabric layer 10 formed by laminating a woven fabric 11, a woven fabric 12 and a woven fabric 13, a compressed layer 20 formed of foamed rubber, and a support layer 30 formed of a woven fabric. And a surface blanket layer 40 made of rubber, and is a flat printing blanket mounted on a blanket cylinder of a double cylinder type printing machine, and a plate cylinder groove during printing by the double cylinder type printing machine On the surface of the surface rubber layer 40 to be in contact with (gap) (a band-like region shown in FIG. 1), a hydrogenation component (γ _s ^h ) of surface tension is 0.7 mN / m or more. This is a blanket in which a cured film 60 is formed of a silicone-based coating material.
In FIG. 2, 51, 52, 53, 54 and 55 are adhesive rubber layers, respectively.

  The base fabric layer 10 of the blanket 100 is formed by bonding a lowermost woven fabric 11, an intermediate woven fabric 12, and an intermediate woven fabric 13. The woven fabric 11 and the woven fabric 12 are bonded by an adhesive rubber layer 51, and the woven fabric 12 and the woven fabric 13 are bonded by an adhesive rubber layer 52.

  The woven fabric 11, the woven fabric 12 and the woven fabric 13 constituting the base fabric layer 10 are each made of, for example, a plain woven fabric made of cotton yarn, and the adhesive rubber layer 51 and the adhesive rubber layer 52 are respectively rubber paste (adhesive rubber layer). It is formed by drying and curing the composition for forming). The rubber (raw rubber) constituting the rubber paste is not particularly limited, but nitrile rubber (NBR) is preferably used.

  The compression layer 20 formed by laminating on the base fabric layer 10 (woven fabric 13) through the adhesive rubber layer 54 imparts a suitable compression characteristic to the blanket 100 and enables good printing by reducing the printing pressure. It is a layer to do. Examples of the constituent material of the compression layer 20 include a foam (foam rubber) made of nitrile rubber. The foam may be open-celled or closed-celled. The adhesive rubber layer 54 is formed by drying and curing rubber paste (composition for forming an adhesive rubber layer). The rubber (raw rubber) constituting the rubber paste is not particularly limited, but nitrile rubber (NBR) is preferably used.

  The support layer 30 laminated on the compression layer 20 via the adhesive rubber layer 55 is made of, for example, a plain woven fabric made of cotton yarn. The adhesive rubber layer 55 is formed by drying rubber glue (composition for forming an adhesive rubber layer). -It is formed by curing. The rubber (raw rubber) constituting the rubber paste is not particularly limited, but nitrile rubber (NBR) is preferably used.

As the rubber (raw rubber) constituting the surface rubber layer 40 laminated on the support layer 30 through the adhesive rubber layer 53, nitrile rubber (NBR), ethylene propylene rubber (EPM / EPDM), butyl rubber (IIR) ), Silicone rubber (Q), chloroprene rubber (CR) and the like, but are not limited thereto.
The adhesive rubber layer 53 between the support layer 30 and the surface rubber layer 40 is formed by drying and curing rubber glue (adhesive rubber layer forming composition). The rubber (raw rubber) constituting the rubber paste is not particularly limited, but nitrile rubber (NBR) is preferably used.

  On the surface rubber layer 40 of the blanket 100, a cured coating 60 is provided along a belt-like region extending in the axial direction (short direction) of the blanket cylinder in the middle of the winding direction (longitudinal direction) when the blanket 100 is wound around the blanket cylinder. Is formed.

The cured film 60 is a film formed by curing a “silicone-based” coating material.
As a result of confirmation by the present inventor, a film formed of a fluorine-based coating material tends to easily accept ink regardless of the value of the hydrogen bond component (γ _s ^h ) of the surface tension described later. When a fluorine-based film is formed on the surface of the surface rubber layer 40, the ink deposited in the groove (gap) of the plate cylinder is positively received and transferred to paper (Comparative Examples 6 to 8 described later). reference).

The cured coating 60 formed on the surface rubber layer 40 has a hydrogen bond component (γ _s ^h ) of surface tension of 0.7 mN / m or more, preferably 1.0 mN / m or more, more preferably 1.1 mN. / M or more.
As a result of repeated studies by the present inventor, it was found that the ink acceptability of a silicone-based cured coating depends on the value of the hydrogen bond component (γ _s ^h ) of the surface tension of the coating.

As will be apparent from the results of Examples described later, excellent repellent properties are not obtained for the first time by a silicone-based cured film having a hydrogen bond component (γ _s ^h ) of surface tension of 0.7 mN / m or more, particularly 1.0 mN / m or more. Ink properties are exhibited, and ink acceptance by the cured coating can be effectively suppressed. As a result, almost no ink or paper dust is received at the portion where the cured coating 60 is formed on the surface of the surface rubber layer 40. As a result, the printed matter can be reliably prevented from being stained.
Even in the case of a silicone-based cured film, if the hydrogen bond component (γ _s ^h ) of the surface tension is less than 0.7 mN / m, it is not possible to prevent the printed matter from being stained (Comparative Examples 2 to 2 described later). 3).
Here, the ink that exhibits ink repellency by the cured coating 60 is not particularly limited, and may be a hydrophobic ink that is commercially available for normal offset printing.

The reason why excellent ink repellency is manifested due to the high value of the hydrogen bond component (γ _s ^h ) of the surface tension (0.7 mN / m or more, particularly 1.0 mN / m or more) is not clear. However, it is presumed that the hydrophobic ink is difficult to adhere to the cured film.

As a method for increasing the value of the hydrogen bond component (γ _s ^h ) of the surface tension, for example, a low molecular weight material having a hydroxyl group at the end is used as a silicone-based coating material and remains on the surface of the formed cured film. The method of increasing the hydroxyl group to be performed can be mentioned.

In the present invention, the value of the hydrogen bond component (γ _s ^h ) of the surface tension in the cured film is determined by the method of Kitazaki and Hata.
Specifically, using three types of liquids whose surface energy (γ _L ) dispersion component (γ _L ^d ), orientation component (γ _L ^p ), and hydrogen bond component (γ _L ^h ) are known, a cured coating film is used. By measuring the contact angle (θ) of each liquid on the surface of the material and substituting it into the theoretical equation of Kitazaki / Hatabe shown below to solve the simultaneous equations, the dispersion component of the surface tension (γ _s ) of the cured coating (γ _s ^The hydrogen bonding component (γ _s ^h ) is determined together with ^d ) and the orientation component (γ _s ^p ).

The cured film 60 in contact with the surface rubber layer 40 is a cured film of a condensation-curing silicone coating material (a film formed by condensation curing).
The cured coating 60 formed by condensation curing has high adhesion and oil resistance to the surface rubber layer 40, and the cured coating 60 does not peel from the surface rubber layer 40 even when subjected to long-time offset printing. Excellent durability as a blanket. Thereby, the stain prevention effect of printed matter can be stably exhibited over a long period of time.

  Peroxide-curing silicone-based coating materials tend to inhibit the curing reaction by air, and as a result, a thin cured film cannot be formed to such an extent that image disturbance will not occur during printing (comparison described later). (See Example 4).

  In addition, the addition-curable silicone-based coating material tends to inhibit the curing reaction by a cross-linking agent or the like contained in the surface rubber layer, so that a cured film cannot be formed (Comparative Example 5 described later). reference).

The width of the cured coating 60 is preferably about 1.5 to 10 times the width of the groove (gap) of the plate cylinder.
When the width of the cured film is too narrow, the printed matter cannot be sufficiently prevented from being stained. On the other hand, when the width of the cured coating is too wide, the printable area becomes narrow, which is not preferable.

  The film thickness of the cured coating 60 is preferably 5 to 100 μm, more preferably 5 to 20 μm.

  If this film thickness is too small, the object of the present invention (to stably exhibit the antifouling effect of the printed matter over a long period of time) may not be sufficiently achieved. On the other hand, if this film thickness is excessive, the pressure applied to the blanket surface may change abruptly at the portion where the cured film is formed, causing image disturbance (shock eyes).

  The cured film 60 may be composed of a silicone resin formed by curing a resin-based coating agent, or may be composed of silicone rubber formed by curing a rubber-based coating agent.

  The cured coating 60 is formed by applying a condensation curable silicone coating material to the surface of the surface rubber layer 40 and curing the coating.

  Here, the application method of the coating material is not particularly limited, and examples thereof include application by a roller and spray, screen printing, and the like.

  Moreover, as hardening conditions of the coating film for obtaining the cured film 60, it is normally 10 to 60 minutes at 20-150 degreeC, Preferably it is 10 to 30 minutes at 140-150 degreeC.

According to the blanket 100 of this embodiment, the cured coating 60 formed on the surface rubber layer 40 has a hydrogen bond component (γ _s ^h ) of surface tension of 0.7 mN / m or more, preferably 1.0 mN / m. Due to the silicone-based coating described above, the cured coating 60 exhibits excellent ink repellency, and ink and paper dust deposited in the groove (gap) of the plate cylinder are hardly accepted in the formed portion. As a result, it is possible to reliably prevent stains on the printed material due to the transfer of these.

  Further, since the cured film 60 formed on the surface rubber layer 40 is a cured film of a “condensation curable” silicone-based coating material, the cured film 60 has high adhesion to the surface rubber layer 40. It is excellent in durability, and according to this, according to the blanket 100 of the present embodiment, it is possible to stably exhibit the effect of preventing printed matter from being stained over a long period of time.

Further, the cured film 60 is formed on the flat surface of the surface rubber layer 40 that comes into contact with the groove of the plate cylinder during printing by a double cylinder type printing machine. No concave portion is formed as in a known blanket.
As a result, not only a complicated processing operation for forming the concave portion is unnecessary, but also the pressure applied to the blanket surface is not suddenly relieved in the portion where the cured coating 60 is formed, so that it can be performed at high speed. Printing does not cause image distortion (shock eyes).

Examples of the present invention will be described below, but the present invention is not limited thereto.
<Example 1>
[1] Blanket production:
A blanket body (360 mm) comprising a base fabric layer formed by laminating three woven fabrics, a compression layer made of NBR foam rubber, a support layer made of woven fabric, and a surface rubber layer made of NBR. X50mm), and a condensation-curing silicone coating agent (resin system) (Shin-Etsu) on the surface of the surface rubber layer (band-like region with a width of 15mm) in the middle of the longitudinal direction (winding direction when mounted on the blanket cylinder) Chemical Industries Co., Ltd.) was applied with a brush and heated in an oven at 150 ° C. for 10 minutes to cure the coating film to form a cured coating film having a thickness of about 10 μm, as shown in FIG. A printing blanket of the present invention having a cross-sectional configuration and a planar shape (dimension) as shown in FIG.

Here, the formulation of NBR constituting the surface rubber layer 40 is as follows.
-Nipol 1042: 100.0 parts by mass-Nocrack # 200: 0.5 parts by mass-Stearic acid 50S: 1.0 parts by mass-Zinc oxide: 5.0 parts by mass-Hacuenca CC: 30.0 parts by mass-Titanium oxide JA-1: 3.0 parts by mass Precipitated sulfur: 2.0 parts by mass Thiocol TP-95: 15.0 parts by mass Noxera CZ-G 3.0 parts by mass

  Further, as a blanket for an endurance test described later, a cured film is formed on the surface of the surface rubber layer (a belt-like region having a width of 15 mm) in the middle in the longitudinal direction of the blanket body (842 mm × 150 mm) in the same manner as described above. Thus, the printing blanket of the present invention having the sectional configuration as shown in FIG. 2 and the planar shape (dimension) as shown in FIG.

[2] Measurement of contact angle and surface tension of cured coating:
A surface rubber layer using three kinds of liquids shown in Table 1 below, whose surface energy (γ _L ) dispersion component (γ _L ^d ), orientation component (γ _L ^p ) and hydrogen bond component (γ _L ^h ) are known. The contact angle (θ) of each liquid on the surface of the cured film formed above was measured.
The contact angle (θ) is measured using an “automatic contact angle meter DM-501” (manufactured by Kyowa Interface Science Co., Ltd.). Was carried out by fitting using an ellipse fitting method.

Subsequently, the contact angle (θ) (average value of n = 5) measured for each liquid, and the dispersion component (γ _L ^d ), the orientation component (γ _L ^p ), and the hydrogen bond of the surface energy (γ _L ) of the liquid By substituting the component (γ _L ^h ) into the above-mentioned theoretical formula of Kitazaki and Hata and solving the simultaneous equations, the dispersion component (γ _s ^d ) and the orientation component (γ _s ^p ) of the surface tension (γ _s ) of the cured film ), And the value of the hydrogen bond component (γ _s ^h ) was determined.
Table 2 shows the measurement results of the contact angle (θ) of each liquid on the surface of the cured film (average value of n = 5) and the values of the components of the surface tension (γ _s ) of the cured film based on these measurement results. Shown in

<Example 2>
Instead of a condensation-curing silicone coating agent (resin), a condensation-curing silicone coating agent (rubber) (manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to the surface of the blanket surface rubber layer to form a cured coating. A blanket having a cross-sectional configuration as shown in FIG. 2 and having a planar shape (dimensions) as shown in FIG. And a blanket for printing according to the present invention having a planar shape (dimensions) as shown in FIG.

Further, in the same manner as in Example 1 [2], the contact angle (θ) of each liquid was measured, and the dispersion component (γ _s ^d ) and the orientation component (γ _s ^p ) of the surface tension (γ _s ) of the cured film were measured. The value of the hydrogen bond component (γ _s ^h ) was determined.
The measurement results of the contact angle (θ) of each liquid on the surface of the cured coating, and the values of the components of the surface tension (γ _s ) of the cured coating based on these measurement results are shown in Table 2 below.

<Comparative Example 1>
The blanket body (360 mm × 50 mm) used in Example 1 was used as a printing blanket according to Comparative Example 1 as a printing blanket having no coating formed on the surface rubber layer.

<Comparative example 2>
Instead of the condensation curable silicone coating agent (resin type), a silane coupling agent “KBE-903” (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the surface of the surface rubber layer of the blanket body to form a cured film. A blanket for printing having a planar shape (dimensions) as shown in FIG. 3 (1) was produced in the same manner as in Example 1 [1] except for the above.

Further, in the same manner as in Example 1 [2], the contact angle (θ) of each liquid was measured, and the dispersion component (γ _s ^d ) and the orientation component (γ _s ^p ) of the surface tension (γ _s ) of the cured film were measured. The value of the hydrogen bond component (γ _s ^h ) was determined.
The measurement results of the contact angle (θ) of each liquid on the surface of the cured coating, and the values of the components of the surface tension (γ _s ) of the cured coating based on these measurement results are shown in Table 2 below.

<Comparative Example 3>
Instead of the condensation curable silicone coating agent (resin type), a silane coupling agent “Si-75” (manufactured by Eponic Degussa Japan) was applied to the surface of the surface rubber layer of the blanket body to form a cured film. A blanket for printing having a planar shape (dimensions) as shown in FIG. 3 (1) was produced in the same manner as in Example 1 [1] except for the above.

Further, in the same manner as in Example 1 [2], the contact angle (θ) of each liquid was measured, and the dispersion component (γ _s ^d ) and the orientation component (γ _s ^p ) of the surface tension (γ _s ) of the cured film were measured. The value of the hydrogen bond component (γ _s ^h ) was determined.
The measurement results of the contact angle (θ) of each liquid on the surface of the cured coating, and the values of the components of the surface tension (γ _s ) of the cured coating based on these measurement results are shown in Table 2 below.

<Comparative example 4>
"TSE-260-5U" (made by Momentive Performance Materials Japan GK) 100 parts by mass, "TC12K" (made by the company) 2 parts by mass, and toluene, the viscosity is 200dPa.sec. A peroxide curable silicone coating agent (rubber type) was prepared.
Instead of the condensation-curing silicone coating agent (resin type), the peroxide-curing silicone coating agent obtained as described above was applied to the surface of the surface rubber layer of the blanket body, and 10 ° C. in an oven at 150 ° C. Although the coating was heated for a minute, the coating film could not be cured. This is presumably because the curing reaction of the coating film was inhibited by air.

<Comparative Example 5>
Instead of a condensation curable silicone coating agent (resin type), an addition curable type silicone coating agent (rubber type) “KE-1935” (manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to the surface of the surface rubber layer of the blanket body. It was applied and heated in an oven at 150 ° C. for 10 minutes, but the coating film could not be cured. This is presumably because the curing reaction of the coating film was inhibited by the crosslinking agent (sulfur) contained in the surface rubber layer.

<Comparative Example 6>
Instead of the condensation curable silicone coating agent (resin type), a fluorine-based surface treatment agent described in Examples of JP-A-2003-253022 is applied to the surface of the surface rubber layer of the blanket body, and 150 A printing blanket having a planar shape (dimensions) as shown in FIG. 3 (1) was produced in the same manner as in Example 1 [1] except that a film was formed by heating in an oven at 10 ° C. for 10 minutes.

Further, in the same manner as in Example 1 [2], the contact angle (θ) of each liquid was measured, and the dispersion component (γ _s ^d ) and the orientation component (γ _s ^p ) of the surface tension (γ _s ) of the cured film were measured. The value of the hydrogen bond component (γ _s ^h ) was determined.
The measurement results of the contact angle (θ) of each liquid on the surface of the cured coating, and the values of the components of the surface tension (γ _s ) of the cured coating based on these measurement results are shown in Table 2 below.

<Comparative Example 7>
Instead of a condensation-curing silicone coating agent (resin type), a fluorine-based surface treatment agent “FC-102 New TFE Coat” (manufactured by Fine Chemical Japan Co., Ltd.) is applied to the surface of the surface rubber layer of the blanket body at 150 ° C. A blanket for printing having a planar shape (dimensions) as shown in FIG. 3 (1) was produced in the same manner as in Example 1 [1] except that a film was formed by heating in an oven for 10 minutes.

Further, in the same manner as in Example 1 [2], the contact angle (θ) of each liquid was measured, and the dispersion component (γ _s ^d ) and the orientation component (γ _s ^p ) of the surface tension (γ _s ) of the cured film were measured. The value of the hydrogen bond component (γ _s ^h ) was determined.
The measurement results of the contact angle (θ) of each liquid on the surface of the cured coating, and the values of the components of the surface tension (γ _s ) of the cured coating based on these measurement results are shown in Table 2 below.

<Comparative Example 8>
Instead of a condensation-curing silicone coating agent (resin type), a fluorine-based surface treatment agent “FC-250” (manufactured by Fine Chemical Japan Co., Ltd.) is applied to the surface of the surface rubber layer of the blanket body. A printing blanket having a planar shape (dimensions) as shown in FIG. 3 (1) was produced in the same manner as in Example 1 [1] except that the film was formed by heating for 10 minutes.

Further, in the same manner as in Example 1 [2], the contact angle (θ) of each liquid was measured, and the dispersion component (γ _s ^d ) and the orientation component (γ _s ^p ) of the surface tension (γ _s ) of the cured film were measured. The value of the hydrogen bond component (γ _s ^h ) was determined.
The measurement results of the contact angle (θ) of each liquid on the surface of the cured coating, and the values of the components of the surface tension (γ _s ) of the cured coating based on these measurement results are shown in Table 2 below.

<Ink transfer test>
An ink transfer test was performed on each of the blankets (360 mm × 50 mm) obtained in Examples 1-2, Comparative Examples 1-3, and Comparative Examples 6-8.
Specifically, using an ink transfer tester (manufactured by IGT), as shown in FIG. 4 (1), an ink roller 72 on which a uniform ink layer 71 is formed with hydrophobic commercial ink (indigo) is formed. The blanket 74 (sample) mounted on the blanket cylinder 73 is brought into contact with the blanket 74 and paper (not shown) mounted on the paper cylinder 75 is brought into contact with the blanket 74 to rotate the ink roller 72, the blanket cylinder 73, and the paper cylinder 75. Thus, a part of the ink in the ink layer 71 was received by the blanket 74 from the ink roller 72, and a part of the ink received by the blanket 74 was further transferred to the paper.
And the stain | pollution | contamination prevention performance to the paper by the said film was evaluated by observing the grade of ink acceptance (ink repellency of a film) in the formation part of a film, and the grade of the ink transfer from a film to paper. The results are also shown in Table 2 below.
Moreover, about the blanket obtained in Example 1, the photograph which image | photographed the blanket surface after a transfer test is shown in FIG. 5 (1), and the photograph which image | photographed paper is shown in FIG. 5 (2).

  The evaluation criteria are as follows. However, for the blanket obtained in Comparative Example 1 in which no coating was formed on the surface rubber layer, only the degree of ink transfer to paper was observed.

〔Evaluation criteria〕
“◯”: On the blanket surface, the ink concentration in the film formation portion is extremely low, and the ink repellency of the film is sufficiently recognized. Also, almost no ink transfer to the paper is observed.
“Δ”: On the blanket surface, the ink concentration in the film formation portion is low, and the ink repellency of the film is recognized. Moreover, although transfer to paper is recognized, it is a grade which is practically acceptable. “X”: On the blanket surface, the ink density of the film-formed part is the same as or higher than the ink density of the non-formed part of the film. Moreover, the transition to paper is recognized notably.

<Oil resistance of coating>
The oil resistance of the coating was evaluated for each of the blankets (360 mm × 50 mm) obtained in Examples 1-2, Comparative Examples 2-3, and Comparative Examples 6-8.
Specifically, after immersing the blanket in an oil-based ink cleaner “Blanklin V” (manufactured by Nicker Co., Ltd.) for 1 hour, the formed part of the film is visually observed to check for swelling, lack, or discoloration. Further, it was confirmed whether or not peeling occurred by rubbing with a waste cloth.
As an evaluation standard for oil resistance, “X” was given when abnormalities such as swelling, missing, discoloration, and peeling were observed, and “◯” when no abnormality was observed. The results are also shown in Table 2 below.

<Durability test of coating>
Each of the blankets (842 mm × 150 mm) obtained in Examples 1 and 2 was subjected to a coating durability test.
Specifically, as shown in FIG. 4 (2), the blanket cylinder 83 is brought into contact with a blanket 84 (sample) mounted on the blanket cylinder 83, and further driven 0.3 mm, the blanket cylinder 83 is rotated at a rotational speed of 15 rpm. And rotated 1 million times. Then, the blanket 84 was removed and the state of the cured film was observed.
As a criterion for evaluating durability, “x” was given when the cured film was peeled off, and “◯” was given when it was not. The results are also shown in Table 2 below.

* 1: Shin-Etsu Chemical Co., Ltd. * 2: Shin-Etsu Chemical Co., Ltd. * 3: "KBE-903" manufactured by Shin-Etsu Chemical Co., Ltd. * 4: "Si-75" manufactured by Eponic Degussa Japan * 5: A mixture of 100 parts by weight of “TSE-260-5U” (made by Momentive Performance Materials Japan GK), 2 parts by weight of “TC12K” (made by the company), and toluene.
* 6: “KE-1935” manufactured by Shin-Etsu Chemical Co., Ltd. * 7: manufactured by Fujikura Rubber Industry Co., Ltd. * 8: “FC-102 New TFE Coat” (manufactured by Fine Chemical Japan)
* 9: “FC-250” (Fine Chemical Japan)
* 10: Contact angle (θ) of distilled water on the surface of the coating
* 11: Contact angle of 1-bromonaphthalene on the surface of the coating (θ)
* 12: Contact angle (θ) of 1,1,2,2-tetrabromoethane on the coating surface

100 Blanket 10 Base fabric layer 11 Woven fabric (lowermost layer)
12 Woven fabric (middle layer)
13 Woven fabric (intermediate layer)
20 Compression layer 30 Support layer 40 Surface rubber layer 51 Adhesive rubber layer 52 Adhesive rubber layer 53 Adhesive rubber layer 54 Adhesive rubber layer 55 Adhesive rubber layer 60 Cured coating 71 Ink layer 72 Ink roller 73 Blanket cylinder 74 Blanket (sample)
75 Paper cylinder 83 Blanket cylinder 84 Blanket (sample)
85 impression cylinder

Claims (5)

A flat printing blanket comprising a base fabric layer formed by laminating a plurality of woven fabrics and a surface rubber layer, and mounted on a blanket cylinder of a double cylinder type printing machine,
The hydrogen bond component (γ _s ^h ) of the surface tension is 0.7 mN / m or more on the flat surface of the surface rubber layer that comes into contact with the groove of the plate cylinder during printing by the double cylinder type printing press. A printing blanket, wherein a cured film is formed of a condensation-curing silicone-based coating material. 2. The printing blanket according to claim 1, wherein the hydrogen bond component (γ _s ^h ) of the surface tension of the cured film is 1.0 mN / m or more. The printing blanket according to claim 1, wherein the hydrogen bond component (γ _s ^h ) of the surface tension of the cured coating is 1.1 mN / m or more.   The printing blanket according to any one of claims 1 to 3, wherein the cured film has a thickness of 5 to 100 µm.   The blanket for printing according to any one of claims 1 to 4, wherein the raw rubber constituting the surface rubber layer is nitrile rubber (NBR).

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