JP2003025752A - Printing blanket with steel bars and method for attaching steel bars to printing blanket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improved method for manufacturing a printing blanket having steel bars at both ends thereof and the printing blanket having the steel bars excellent in adhesive strength or solvent resistance. SOLUTION: The printing blanket 10 with the steel bars is obtained by bonding a thermally adhesive film comprising an olefinic resin to one surface of each of the steel bars 20 and subsequently bonding the surface on the side having the thermally adhesive film of each of the steel bars 20 to each of the opposed end parts 15 of the printing blanket 10 and subsequently bonding the steel bars 20 and the end parts 15 of the printing blanket 10 while heating both of them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate-shaped printing blanket having steel bars at both end portions and a method for mounting the steel bars.

[0002]

2. Description of the Related Art Mounting of a printing blanket on a blanket cylinder is carried out, for example, as shown in FIG. 6, in a relatively thin and elongated plate-like shape at opposite ends 91 of a printing blanket 90. A steel bar (elongate plate-shaped spring steel) 92 is adhered, and the end portion 91 is connected to the tension bar 95 from the gap portion 94 of the blanket cylinder 93.
It is realized by inserting it into the mounting groove 96 of.

Conventionally, the following operations (1) to (7) were required to bond the steel bar to the end of the printing blanket. (1) Polish one side of the steel bar with a polishing machine (usually
After 2 times or more), wipe off with a dry cloth to remove the abrasive. (2) Wipe the polished surface of the steel bar with a waste cloth soaked with a solvent (toluene, etc.) to completely remove the oil that inhibits adhesion (degreasing). (3) A masking tape is attached to the unpolished surface of the steel bar, and an adhesive is applied to the polished surface (generally, a chlorinated polyethylene adhesive manufactured by Lord Corp. (USA), trade name "Chemlock", model number "481". Etc.] and then fully dried (usually 90 minutes or more). (Usually, in addition to this operation, another adhesive (for example, trade name "Chemlock" manufactured by the same company, model number "69S", etc.) is coated and dried to form an adhesive layer consisting of two layers. Thus, after forming the adhesive layer on the polished surface of the steel bar, the masking tape on the unpolished surface is peeled off. (4) On the other hand, the back surface of the printing blanket (the surface on the opposite side of the front surface printing layer) is glued with rubber and dried sufficiently (usually 90 minutes or more). The rubber glue requires a thickness of 0.1 mm or more in order to maintain sufficient adhesive strength. (5) Use the steel bar coated with the adhesive in (3) above
Set on the opposite ends (both ends) of the printing blanket glued in (4). (6) The end of the printing blanket is put into a press machine and heated and pressed to bond the printing blanket and the steel bar. The press conditions are usually 160 to 170 ° C. and 3
Set to about 15 minutes at MPa. (7) After pressing, remove the rubber paste protruding from the steel bar with a spatula.

As described above, the process of adhering the steel bar to the end portion of the printing blanket requires an extremely time-consuming operation throughout the entire adhering process, especially because the steps of coating and drying the adhesive are complicated. Because you have to
There was a problem of low production efficiency. In addition, an adhesive such as the above-mentioned product name "Chemlock" which is commonly used for bonding metal and rubber has a problem that it is difficult to adjust the amount of the adhesive used during coating. Further, when a cleaning liquid having a strong aroma component is used to remove the printing ink or the like from the surface of the printing blanket, there is a problem that the adhesive melts and the adhesive strength of the steel bar is lowered.

Therefore, it is an object of the present invention to provide an improved method of manufacturing a printing blanket having steel bars at both ends, and a printing blanket having improved adhesion strength and solvent resistance of the steel bars. Is.

[0006]

Means for Solving the Problems and Effects of the Invention As a result of intensive studies to solve the above problems, the inventors of the present invention applied an adhesive to the surface of a steel bar and applied it to the back surface of a printing blanket. Rather than adopting the conventional method of applying rubber glue and then adhering both, a method of adhering the printing blanket and the steel bar via a heat-adhesive film made of an olefin resin was adopted. In this case, the adhesion between the two can be achieved by a simple method, and the adhesion strength between the both can be made equal to or higher than that of the conventional method. Furthermore, in addition to the printing blanket and the steel bar, The present invention has been completed by discovering a new fact that the solvent resistance of the adhesive portion of can be improved.

That is, the printing blanket with a steel bar according to the present invention has a steel bar bonded to the opposite ends of the printing blanket with a heat-adhesive film made of an olefin resin interposed therebetween. . In addition, the method of attaching the steel bar to the printing blanket according to the present invention comprises attaching a heat-adhesive film made of an olefin resin to one surface of the steel bar and then providing the heat-adhesive film of the steel bar. The side surfaces are adhered to the opposite ends of the printing blanket, respectively, and then the steel bar and the end of the printing blanket are heated and pressed together.

The conventional method, which requires the coating of the adhesive on the steel bar and the coating of the rubber paste on the printing blanket, requires a great number of steps because the coating (coating) and drying steps need to be repeated several times. There was a problem. On the other hand, in the present invention for adhering the printing blanket and the steel bar using the heat-adhesive film, it is not necessary to go through the drying step, and the time required for adhering the steel bar and the printing blanket is significantly increased. It can be shortened. Further, it is not necessary to perform coating (application process) of the adhesive or the like, and therefore it is not necessary to strictly control the amount of the adhesive or the like used.

As described above, according to the printing blanket with a steel bar and the method of attaching the steel bar to the printing blanket according to the present invention, it is possible to realize the simplification of the adhering process. The blanket productivity can be improved. Furthermore, in the present invention, the adhesive strength between the printing blanket and the steel bar can be made equal to or higher than that of the conventional method. Also, since the olefin thermal adhesive film is used to adhere the printing blanket to the steel bar, it has good resistance (solvent resistance) to cleaning liquid etc. for removing printing ink from the surface of the printing blanket. Can be

In the printing blanket with a steel bar and the method for attaching the steel bar to the printing blanket according to the present invention, the olefin resin is preferably polypropylene, polyethylene or a mixed resin thereof. Further, in the printing blanket with a steel bar and the method for attaching the steel bar to the printing blanket according to the present invention, the thickness of the heat-adhesive film is preferably 120 to 200 μm.

By setting the kind of the olefin resin and the thickness of the heat-adhesive film as described above, the adhesive strength between the printing blanket and the steel bar can be further improved. In the method for attaching a steel bar to a printing blanket according to the present invention, it is preferable that the heating and pressure-bonding treatment be performed at a temperature equal to or higher than the melting point of the heat-adhesive film for 1 to 10 minutes.

When the olefin resin is polypropylene, polyethylene, or a mixed resin thereof, the heating and pressure-bonding treatment is preferably performed at 160 to 180 ° C. for 1 to 3 minutes. By setting the conditions at the time of the adhesion treatment between the printing blanket and the steel bar as described above, the adhesion strength between the printing blanket and the steel bar can be further improved.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a printing blanket with a steel bar according to the present invention and a method for attaching the steel bar to the printing blanket will be described in detail. [Thermal Adhesive Film] In the present invention, an olefinic thermal adhesive film is used for adhering the printing blanket and the steel bar.

Examples of the olefin resin film include films made of various conventionally known olefin resins such as polyethylene, polypropylene, polybutylene, and mixed resins thereof. Above all, it is preferable to use a polypropylene film from the viewpoint of improving the adhesive strength between the printing blanket and the steel bar. The thickness of the heat-adhesive film is not particularly limited, but it is required to be 120 to 200 μm in order to improve the adhesive strength between the printing blanket and the steel bar. If the thickness of the heat-adhesive film is less than the above range, sufficient adhesive strength may not be obtained. On the contrary, even if the thickness of the heat-adhesive film exceeds the above range, the effect of improving the adhesive strength is poor, and the adhesive strength may be rather lowered. In addition, there is a possibility that the time required for adhesion becomes long and the productivity decreases.

The lower limit of the thickness of the heat-adhesive film is preferably 150 μm in order to further improve the adhesive strength. When a resin film other than an olefin resin or a rubber film is used as the heat-adhesive film, the resistance to a solvent such as used for cleaning a printing blanket is not sufficient, as shown in Comparative Examples described later. Therefore, there arises a problem that the adhesion between the printing blanket and the steel bar is broken by repeated washing.

[Steel Bar] In the present invention, the material of the steel bar attached to the opposite ends of the printing blanket is not particularly limited, and carbon-based,
Various steels such as manganese chromium base can be used. The steel bar has a mounting groove 96 as shown in FIG.
Among the steels, those having spring property, that is, spring steel are preferable in order to achieve good internal stability and to achieve the purpose of securely fixing the printing blanket.

The size of the steel bar is not particularly limited, but in consideration of making the stability in the mounting groove 96 good and making the gap of the blanket cylinder as narrow as possible. , Usually its thickness t
Is set to 0.4 to 0.7 mm and the width w is set to 12 to 20 mm (see FIG. 6). The length of the steel bar is not particularly limited because it is set according to the width of the printing blanket, but is generally set in the range of 400 to 1100 mm. .

[Adhesion of Thermal Adhesive Film to Steel Bar] As a method of adhering the thermal adhesive film 21 to the steel bar 20, for example, the thermal adhesive film 21 and steel which are cut into a predetermined size in advance are used. There is a method in which the bar 20 is passed between a pair of heat rollers or sandwiched by a press machine to heat and press-bond. However, the steel bar is extremely thin and elongated as described above. Therefore, the above method has a problem that it is difficult to align the steel bar and the heat-adhesive film. If there is a misalignment and the part where the heat-adhesive film protrudes from the steel bar occurs, there is a risk that the heat-adhesive film will adhere to the press when the printing blanket and the steel bar are adhered. There is. Therefore, although the above-mentioned alignment needs to be performed strictly, the fact that the heat-adhesive film itself made of an olefin resin does not have tackiness also contributes to making alignment difficult.

Therefore, for example, as shown in FIGS. 2 (a) and 2 (b), a plurality of steel bars 20 are formed on the heat-adhesive film 21.
Side by side, the heat adhesive film 21 and the steel bar 20
It is preferable to bond and. Figure 2
As shown in (a), a method of passing the heat-adhesive film 21 and the steel bar 20 between a pair of heat rollers 25 to heat and press them, and as shown in FIG. A method of press-bonding the adhesive film 21 and the steel bar 20 with a pair of press machines 26 may be mentioned.

Thermal adhesive film 2 on steel bar 20
When sticking No. 1, it is necessary to set the heating temperature to be equal to or higher than the melting temperature of the heat-adhesive film 21 so that the adhesive strength between the two is sufficient. The suitable range of heating temperature varies depending on the material of the heat-adhesive film used, but is generally 160 ° C. or higher. When the heating temperature is below the range,
There is a possibility that sufficient adhesive strength cannot be obtained. on the other hand,
The heating temperature needs to be set within a range in which the heat-adhesive film does not undergo thermal deterioration, modification or thermal decomposition. Specifically, although it depends on the material of the heat-adhesive film used, it is preferably set within the range of 200 ° C. or lower. The degree of pressurization at the time of sticking is not particularly limited, but it is preferable to apply a pressure such that an iron is used to press it down by hand.

By adhering the steel bar 20 and the heat-adhesive film 21 in this way, the heat-adhesive film 21 is cut in accordance with the size of the steel bar 20 and the steel bars 20 are separated one by one. The steel bar 20 having the heat-adhesive film 21 on one surface can be obtained. The separation of the steel bar 20 is performed, for example, in FIG.
As shown in FIG. 2, the heat-adhesive film 21 having a plurality of steel bars 20 is placed on the pedestal 27, and the steel bars 2
It is performed by cutting the heat-adhesive film 21 with the Thomson cutter 28 set according to the width of 0.

[Printing Blanket] The printing blanket in the printing blanket with a steel bar of the present invention is not particularly limited, and various conventionally known printing blankets can be mentioned. Specifically, as shown in FIG. 1 (a), the front surface printing layer 11 and the base cloth layer (upper base cloth layer) 13 in this order from the front surface printing layer 11 side.
d, compressible layer 12 and base fabric layer (lower base fabric layer) 13a to
Examples of the blanket include a printing blanket 10 (so-called air type) having a support layer made of 13c and a blanket having no compressible layer 12 (so-called solid type).

There are no particular restrictions on the materials used for the surface printing layer 11, the compressible layer 12, and the base cloth layers 13a to 13d, such as the particles for forming cells, the base cloth, and the like. The material can be used. Further, the number of lower base fabric layers 13a to 13c to be laminated is not limited to that shown in FIG. 1, and may be appropriately set according to the total thickness of the printing blanket 10.
[Attachment of Steel Bar to Printing Blanket] To attach the steel bar 20 to the printing blanket 10, the steel bar is temporarily adhered to the end 15 of the printing blanket 10, and then the press machine is used. It is preferable to carry out the procedure in which both are permanently bonded. By performing the procedure of temporary adhesion, it is possible to prevent the fixed position of the steel bar 20 from being displaced.

Printing blanket 10 and steel bar 2
The temporary adhesion with 0 is performed on the surface of the steel bar 20 on which the heat-adhesive film 21 is provided and the surface of the printing blanket 10 (usually the surface opposite to the surface printing layer 11 as shown in FIG. 1 (b)). The surface of the base cloth layer 13a) is combined with the base cloth layer 13a).
This temporary adhesion may be performed, for example, by heating and pressing both end portions 20a and the central portion 20b of the steel bar,
It is not necessary to adhere the entire surface of the steel bar 20 to the printing blanket 10. Specifically, at the stage of temporary adhesion,
It suffices that the steel bar 20 is adhered to the printing blanket 10 so as not to be easily displaced.

For temporary adhesion, the heating temperature is controlled by the heat-adhesive film 2.
It is necessary to set the melting temperature above 1. The suitable range of heating temperature varies depending on the material of the heat-adhesive film used, but is generally 160 ° C. or higher. If the heating temperature is lower than the above range, sufficient adhesive strength may not be obtained. On the other hand, the heating temperature is
It must be set within the range that does not cause denaturation or thermal decomposition. Specifically, although it depends on the material of the heat-adhesive film to be used, it is preferably set in the range of 200 ° C. or lower. The degree of pressurization at the time of sticking is not particularly limited, but it is preferable to apply a pressure such that an iron 29 is used to press it down by hand.

After the temporary adhesion of the steel bar 20, for example, as shown in FIG.
As shown in FIG. 5, the steel bar 20 and the printing blanket 10 are introduced into the press machine 30 and pressed against each other while being fixed by the die 31, so that they can be firmly bonded. In this way, the printing blanket with a steel bar according to the present invention is obtained. The press conditions for the main adhesion are as follows. The heating temperature at the time of main adhesion is not lower than the melting temperature of the heat-adhesive film, and is usually 160 ° C. or higher. If the heating temperature is lower than the above range, sufficient adhesive strength may not be obtained. In the present invention, the melting point of the olefin resin used as the heat-adhesive film is about 120 to 140 ° C.

On the other hand, it is necessary to set the heating temperature at the time of the main adhesion within a range in which the heat-adhesive film and the printing blanket do not undergo thermal deterioration, modification or thermal decomposition. Specifically, although it depends on the material of the heat-adhesive film to be used, it is preferably set in the range of 200 ° C. or lower. 20
If it exceeds 0 ° C, the heat-adhesive film or the printing blanket may be deteriorated by heat. The pressure and time at the time of press at the time of the main adhesion do not significantly affect the relationship between the peeling strength between the printing blanket and the steel bar. However, if the pressure is too small or the time is too short, the adhesion may be insufficient. On the contrary, even if the pressure is excessively increased or the time is excessively lengthened, a corresponding effect cannot be obtained, so that the amount of waste is increased.

The press pressure at the time of main adhesion is usually 0.1 to 5
It is set to be MPa. Press pressure is 0.1MP
If it is less than a, sufficient adhesive strength may not be obtained. On the other hand, when it exceeds 5 MPa, the amount of the heat-adhesive film protruding from the steel bar increases, and the film adhered to the mold or the work may adhere. If the melt of the heat-adhesive film adheres to the mold or the work, there is a problem that it takes a lot of time to remove the melt.

The pressing time for the main adhesion is usually 1 to 10
Set to be minutes. If the pressing time is less than 1 minute, sufficient adhesive strength may not be obtained. On the contrary, even if the pressing is performed for more than 10 minutes, the effect of further enhancing the physical properties such as the adhesive strength is poor, and the productivity is rather lowered. In the printing blanket with a steel bar thus obtained, the peel strength between the steel bar and the printing blanket is not particularly limited, but in a normal state, that is, in a state of being left at room temperature,
It is preferable to set it to be 3.0 kg / cm or more. If the peel strength in the normal state is less than the above range, the steel bar may peel off or fall off during use of the printing blanket. The peeling strength between the steel bar and the blanket for printing is 3.5 k in the above range.
It is preferably at least g / cm.

The printing blanket is repeatedly subjected to a washing treatment for removing the printing ink adhering to the surface during its use. Therefore, the bonded portion between the steel bar and the printing blanket is required to have resistance (solvent resistance) to the solvent used for the cleaning treatment. The degree of solvent resistance can be evaluated by, for example, immersing the printing blanket in a solvent used as a cleaning liquid for a predetermined period and measuring the peel strength between the steel bar and the printing blanket after the immersion.

In order for the solvent resistance to be good, the peel strength between the steel bar and the printing blanket after immersing the printing blanket in the solvent for 4 days is 2.5 kg.
It is required to be f / cm or more, preferably 3.0 kgf / cm. In the method for attaching a steel bar to a printing blanket according to the present invention, the heating and pressure-bonding treatment is performed at a temperature equal to or higher than the melting point of the heat-adhesive film.
It is preferably carried out for 10 minutes, and when polypropylene, polyethylene or a mixed resin thereof is used as the olefin resin, it is 1 to 1 at 160 to 180 ° C.
More preferably, it is carried out for 0 minutes. By setting the conditions at the time of the adhesion treatment between the printing blanket and the steel bar as described above, the adhesion strength between the printing blanket and the steel bar can be further improved.

In order to manufacture a printing blanket with a steel bar, first, a thermal adhesive film 21 is attached to the opposite ends 15 of the printing blanket 10, and the steel bar 20 is placed on the thermal adhesive film 21. After placing
A case may be considered in which the steel bar 20 and the printing blanket 10 are pressed into contact with each other by the press machine 30 and the two are bonded together. However, with this method,
A step of adhering a heat adhesive film to a printing blanket, a step of temporarily adhering a steel bar on the film,
The printing blanket is subject to heat history and pressure history over the three steps of the main adhesion between the steel bar and the printing blanket, which is not preferable in that the quality of the blanket may be deteriorated.

[0033]

[Manufacture of printing blankets with steel bars]

Example 1 (Preparation of printing blanket) A printing blanket 10 having a layer structure shown in FIG. 1 (a) (total thickness 1.98 mm)
Was prepared according to a conventional method. The surface printing layer 11 was formed by using a rubber composition prepared by mixing acrylonitrile-butadiene rubber (NBR) with a vulcanizing compounding agent. The base cloths 13a to 13d were formed by impregnating a cotton cloth (thickness: 0.3 mm) with a rubber paste prepared by mixing a vulcanizing compounding agent or the like in NBR and dissolving it in toluene. Figure 1 (a)
Reference numeral 12 indicates a compressible layer.

(Production of Steel Bar with Thermal Adhesive Film) On the thermal adhesive film 21 made of polypropylene (PP), a steel bar made of carbon steel (length: 920 m)
m, width 20 mm, thickness 0.5 mm) 20 are arranged side by side, and as shown in FIG.
While heating to 65 ° C., they were pressure-bonded to each other to bond them. Here, the PP film as the heat-adhesive film includes the product name “Admer (R) Film QE-0” manufactured by Tohcello Co., Ltd.
60 "[thickness 150 μm, melting point 139 ° C., melt index 7.0 g / 10 min].

Further, as shown in FIG. 3, the steel bar 20 adhered on the heat-adhesive film 21 is separated and cut by the Thomson cutter 28 to obtain the steel bar 20 having the heat-adhesive film 21. It was (Attachment of Steel Bar to Printing Blanket) Steel bars 20 provided with the above-mentioned heat-adhesive films 21 are placed on opposite ends 16 of the surface of the base fabric layer 13a of the printing blanket 10 respectively, Steel bar 2 concerned
0 at both end portions 20a and the central portion 20b
Temporary adhesion was performed by lightly pressing with an iron at 65 ° C. (see FIG. 4).

After temporary adhesion, the end 16 of the printing blanket
And the steel bar 20 is introduced into the press machine 30,
By press contacting at 65 ° C. and 3 MPa for 15 minutes, strong adhesion between the printing blanket 10 and the steel bar 20 was realized (see FIG. 5). Thus, a printing blanket with a steel bar according to the present invention was obtained. Examples 2 and 3 With the steel bar as in Example 1, except that the conditions such as the thickness of the heat-adhesive film, the pressure of the press at the time of the main adhesion, and the pressing time were changed as shown in Table 1. A blanket for printing was manufactured.

Examples 4 and 5 A polyethylene (PE) film was used as the heat-adhesive film, and the conditions such as the thickness of the heat-adhesive film, the pressure of the press at the time of the main adhesion, and the press time are shown in Table 1. A blanket for printing with a steel bar was manufactured in the same manner as in Example 1 except that the setting was made as follows. Above PE
The film has the product name “Admar (R)” manufactured by Tohcello Co., Ltd.
Film NE-058 "[melting point 120 [deg.] C., melt index 0.92 g / 10 min] was used.

Comparative Examples 1 to 5 Ethylene-vinyl acetate copolymer (EVAC) film (Comparative Example 1), polyurethane (P
UR) film (Comparative Example 2), polyester film (Comparative Example 3), acrylic resin film (Comparative Example 4) or acrylonitrile-butadiene rubber (NBR) film (Comparative Example 5), and the thickness of the heat-adhesive film A printing blanket with a steel bar was manufactured in the same manner as in Example 1 except that the conditions such as the pressure of the pressing machine and the pressing time at the time of the main adhesion were set as shown in Table 2.

The heat-adhesive films used in Comparative Examples 1 to 5 are as follows. EVAC film: Product name "ELFAN OH501" manufactured by Nippon Matai Co., Ltd. (thickness 150 μm) or product name "Admer Film VE-30 manufactured by Tohcello Co., Ltd."
0 "(thickness 50 μm, melting point 90 ° C.) three layers [In Comparative Example 1, the above-mentioned“ ELFAN OH50 ”was used.
1 "and" Admer film VE-300 "(three layers) were tested respectively. ] PUR film: Product name "L-Phan UH203" manufactured by Nippon Matai Co., Ltd. (thickness 150 μm) Polyester film: Product name "L-Phan PH413" manufactured by Nippon Matai Co., Ltd. (thickness 150 μm) Acrylic resin film: Nitto Product name "M
5200 "(thickness 150 μm) NBR film: trade name“ T530 ”manufactured by Nitto Denko Corporation
0 ”(thickness 150 μm) One surface of the same steel bar used in Control Example 1 was polished twice or more with a polishing machine, and then wiped with a dry cloth to remove the polishing portion. Next, the surface of the steel bar was wiped off with a waste cloth soaked with a solvent (toluene) to remove the oil component that inhibits the adhesion (degreasing).

After degreasing, a masking tape was attached to the unpolished surface of the steel bar, and an adhesive was applied to the polished surface [chlorinated polyethylene adhesive manufactured by Rhode (USA), trade name "Chemlock", model number "205"). After coating, it was dried for 90 minutes. Further, another kind of adhesive [product name "Chemlock", model number "252" manufactured by the same company) was applied to the coated surface of the adhesive and dried, and then the masking tape on the unpolished surface was peeled off. On the other hand, a rubber paste was applied to the back surface (base fabric 13a side) of the same printing blanket 10 used in Example 1, adjusted to have a thickness of 0.1 mm, and then dried for 90 minutes. It was

The above steel bars (coated with an adhesive) are set at opposite ends (both ends) of a printing blanket and put into a press machine, and the temperature is 165 ° C. and the pressure is 3 MP.
The blanket 10 for printing (base cloth layer 13a) and the steel bar 20 were adhered by pressing for 15 minutes under the condition a. After pressing, the rubber paste protruding from the steel bar 20 was removed with a spatula to obtain a printing blanket with a steel bar.

[Evaluation of Physical Properties] (a) Peel Strength A tensile test was conducted on the printing blankets with steel bars obtained in the above Examples and Comparative Examples, and the peel strength between the length steel bar 20 and the printing blanket 10 (peeling Force) was measured. The tensile test is JIS K 6854.
The test was carried out in accordance with the regulations of "Test method for peeling adhesive strength of adhesive".

The samples used were those obtained by cutting the printing blanket according to the width of the steel bar from the printing blanket with a steel bar obtained in the above Examples and Comparative Examples. The length of the sample was about 150 mm, and the length of the bonded portion was 70 mm. The steel bar (rigid substrate) and printing blanket (flexible substrate) of this sample are shown in FIG. 6 of JIS K 6854 8.1.
As shown in (180 ° peeling), they were attached to the grips of the tensile tester. Then, the two grips were pulled in opposite directions at a pulling speed of 50 mm / min to determine the peel strength (kgf / cm) when peeling between the steel bar and the printing blanket occurred.

The measurement was carried out in the normal state (state left at room temperature)
Two kinds of samples, that is, after immersion in a solvent, were performed. The sample after soaking in solvent was immersed in a cleaning solution for 4 days with a cleaning solution [ink-only cleaning solution made by Tokyo Ink Co., Ltd., product name "Ochil", containing aroma component (aromatic hydrocarbon)]. I used the one. (b) Protrusion amount After press-bonding the printing blanket and the steel bar, it was visually confirmed whether or not the heat-adhesive film was protruding from the periphery of the steel bar, and if it was protruding, the extent of the protrusion amount was evaluated. .

The criteria for evaluating the amount of protrusion are as follows. A: Little or no protrusion of the heat-adhesive film was observed. B: Although the heat-adhesive film was squeezed out,
The amount was not a problem for practical use. C: Protrusion of the heat-adhesive film was remarkable.

(C) Overall evaluation A: All evaluation items were extremely good or practically sufficient. B: Some evaluation items were found to be slightly inadequate, but this was not a problem for practical use. C: Insufficient points were found in some evaluation items or all evaluation items, and the characteristics of the printing blanket were not practically sufficient.

Evaluation by comprehensively judging the material and thickness of the heat-adhesive film, press conditions (temperature, pressure, time) at the time of adhering the steel bar, the above-mentioned measurement results (peel strength, amount of protrusion), and the above-mentioned requirements. The results are shown in Table 1 and Table 2.
Shown in.

[0048]

[Table 1]

[0049]

[Table 2]

In Tables 1 and 2, "PP" in the "Material for heat-adhesive film" column is polypropylene, "PE" is polyethylene, "EVAC" is ethylene-vinyl acetate copolymer, and "PUR" is polyurethane. , "Ester" is polyester, "acrylic" is acrylic resin, "N"
“BR” represents acrylonitrile-butadiene rubber. As is clear from Tables 1 and 2, a heat-adhesive film made of an olefin resin is used,
It was found that in Examples 1 to 5 in which the heating / heating conditions during pressing were set within the above-mentioned preferable ranges, the peel strength was high both in the state and after the immersion in the solvent, and it had extremely excellent physical properties. . In particular, since the peel strength shows a high value even after the immersion in the solvent,
It was found that the printing blankets of ~ 5 also had good solvent resistance.

On the other hand, Comparative Examples 1 to 5 all use a non-olefin type heat-adhesive film, which has a low peel strength in a normal state and has a steel bar having an adhesive property after being immersed in a solvent. There was a problem of being damaged.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a printing blanket with a steel bar according to the present invention, in which (a) is a sectional view thereof and (b) is a perspective view thereof. Polyolefin resin sheet

2A and 2B are explanatory views showing an example of a method for sticking a heat-adhesive film to a steel bar, wherein FIG. 2A shows a method using a heat roller and FIG. 2B shows a method using a press machine.

FIG. 3 is an explanatory view showing a method of cutting the heat-adhesive film into steel bars.

FIG. 4 is an explanatory diagram showing a method of temporarily adhering a steel bar to an end portion of a printing blanket.

5A and 5B are explanatory views showing a step of adhering a printing blanket and a steel bar with a press machine, in which FIG. 5A is a perspective view thereof, and FIG. 5B is a side view thereof.

FIG. 6 is an explanatory diagram showing an example of a mounting mechanism for a printing blanket.

[Explanation of symbols]

10 Printing blanket 15 edge 20 Steel bar (spring steel) 21 Thermal adhesive film

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yuji Yamazaki             3-6-9 Wakihama-cho, Chuo-ku, Kobe-shi, Hyogo               Sumitomo Rubber Industries, Ltd. F-term (reference) 2H114 CA10 DA04 DA47 DA73 EA08                       FA01 FA09 FA14 GA12 GA38

Claims (8)

[Claims] 1. A printing blanket with a steel bar, wherein a steel bar is adhered to the opposite ends of the printing blanket with a heat-adhesive film made of an olefin resin interposed therebetween. 2. The olefin resin is polypropylene,
The printing blanket with a steel bar according to claim 1, which is polyethylene or a mixed resin thereof. 3. The thickness of the heat-adhesive film is 120 to 2
The printing blanket with a steel bar according to claim 1, having a size of 00 μm. 4. A heat-adhesive film made of an olefin-based resin is adhered to one surface of a steel bar, and the surface of the steel bar on which the heat-adhesive film is provided is provided on opposite ends of a printing blanket. A method of attaching a steel bar to a printing blanket, characterized in that the steel bar and the end portion of the printing blanket are adhered to each other and then the two are pressed against each other while heating. 5. The olefin resin is polypropylene,
The method for attaching a steel bar to a printing blanket according to claim 4, which is polyethylene or a mixed resin thereof. 6. The thickness of the heat-adhesive film is 120 to 2
The method for attaching a steel bar to a printing blanket according to claim 4, wherein the steel bar has a diameter of 00 μm. 7. The method of attaching a steel bar to a printing blanket according to claim 4, wherein the heating and pressure treatment are performed at a temperature equal to or higher than the melting point of the heat-adhesive film for 1 to 10 minutes. 8. The olefin resin is polypropylene,
The method for attaching a steel bar to a printing blanket according to claim 4, wherein the heating and pressure-bonding treatment is performed at 160 to 180 ° C. for 1 to 10 minutes using polyethylene or a mixed resin thereof.