JPS6148437B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a composition for manufacturing a compressed layer of a printing blanket, particularly a compressible blanket, and a method for manufacturing a compressed layer of a compressible blanket using the composition. Printing blankets used in high speed offset printing have been provided with compressed layers of elastomeric polymers. Firstly, the compressed layer described above uniformly absorbs the bulge that occurs on the compressed surface of the blanket during printing pressure, thereby reducing deformation of the blanket surface and making it possible to obtain a clear image. Secondly, due to the presence of this compression layer, when printing paper is folded or sent in piles of two or more sheets, the compression layer compresses,
It absorbs forces (other than printing pressure) applied to the surface of the plate cylinder and blanket, thereby significantly improving the life of the plate cylinder and blanket surface layer. Thirdly, when tailoring the torso, for ordinary blankets, the thickness must be adjusted very precisely, but by providing a compression layer, it is possible to make the torso slightly oversized than the standard torso tailoring. It has the advantage that it is possible to obtain clear printing, and that the body can be tailored regardless of the skill level of the operator. It is known to manufacture such compressed layers from foam. For example, a foaming agent is blended into synthetic rubber and heated and foamed during vulcanization of the rubber to form a compressed layer with countless closed cells, or a method of curing as disclosed in JP-A No. 48-97609. There is a method in which fine latex spongy rubber particles are dispersed in an elastic substrate to form a large number of unconnected pores (closed cells) in the substrate. Furthermore, a method (Japanese Patent Publication No. 7371/1983) is known in which hollow microspheres are dispersed in an elastomer to form closed cells. However, printing blankets with compressed layers as described above do not fully achieve the effect of providing a compressed layer. That is, the compressed layer cannot sufficiently and uniformly absorb the bulge that occurs on the compressed surface of the blanket during printing pressure, making it impossible to form a clear image. Furthermore, during printing, since the plate cylinder rotates at high speed, the blanket is compressed at an extremely high speed, and compression strain must be alleviated at a response speed proportional to this compression speed. has the disadvantage of slow response speed. This is basically due to the fact that the compressed layer of the above-mentioned known blanket is a closed cell foam. This is because in a closed cell system, the air is separated individually, so there is no place for the air within the bubbles to escape due to compressive deformation, and the deformation due to compressive stress cannot be fully absorbed.In addition, the relaxation rate of compressive strain is slow. Because it will be late. In the case of open cells, the pores communicate with each other, so air can circulate freely and can freely buffer against large compressive deformations, and the relaxation rate of compressive strain is The printing quality is significantly improved, making it possible to obtain clear printing, and in addition, it becomes possible to improve the durability of the plate cylinder and blanket. As described above, it is desirable that the compressed layer of a printing blanket is made of foam with a high open cell ratio, but as mentioned above, closed cell foams are mainly used because they have a high open cell ratio. Furthermore, it is extremely difficult to produce a foam having micropores, which is an essential factor for obtaining halftone dot reproducibility in printed matter. For example, in a rubber foam foamed with an organic foaming agent, it is difficult to provide uniform micropores of 100 μm or less, and the open cell ratio is extremely low at 50% or less. Third
The figure is a 75x microscopic photograph of a foam produced by this method. As is clear from the figure, the bubbles are not uniform in size, ranging from large to small, and the open cell ratio is low. Also, according to the method of mixing hollow microspheres into elastomer (Japanese Patent Publication No. 7371/1989),
Since pre-manufactured microspheres are mixed in, it is easy to adjust the size of the bubbles, but since the mixed microspheres are individual spheres, the bubbles are 100% closed cells. In addition, in the method of dispersing fine particles of cured latex spongy rubber in a substrate to form a compressed layer (Japanese Patent Application Laid-open No. 1976-97609), it is possible to produce a foam with small bubbles. It is time-consuming to manufacture, and has the drawback of clogging the doctor knife during rubber sizing, resulting in poor production efficiency, and the open cell ratio is not 100%, so its performance as a compressed layer is not sufficient. The present invention aims to eliminate the above-mentioned drawbacks and provide a composition for producing a foam with 100% open cells and micropores of 100 μm or less, and a method for producing a printing blanket using the composition. purpose. Therefore, the composition for producing a compressed layer of a printing blanket according to the present invention comprises a polymer solution comprising a polymer dissolved in a solvent at a polymer concentration of 2 to 70%;
One or more surfactants having at least one functional group selected from sulfonic acid groups, ether groups, and hydroxyl groups or having an amine structure and/or a sufficient amount of silicone to exhibit an antifoaming effect. In addition, powdered crystals and/or cellulose with an average length of 300 μm or less are added to the polymer solution in an amount of 30% or less, and a gelling liquid that is soluble in the solvent of the polymer solution but not dissolved in the polymer. It is characterized in that it basically consists of adding 20 to 95% of the amount necessary for the polymer solution to gel. In addition, the method for manufacturing the compressed layer of the printing blanket according to the present invention includes using a polymer in a solvent at a polymer concentration of 2.
Adding one or more surfactants having a sulfonic acid group, ether group, or amine structure and/or a sufficient amount of silicone to exhibit an antifoaming effect to a polymer solution dissolved at ~70%. , powder crystals and/or cellulose with an average length of 300 μm or less are added to the polymer solution at 30%
% or less, and furthermore, a gelling liquid that is soluble in the solvent of the polymer solution but not soluble in the polymer is added in an amount of 20 to 95% of the amount necessary for the polymer solution to gel. The composition for producing a compressed layer of a printing blanket is coated on a base fabric, immersed in a gelatinizing solution, solvent removed, dried, and optionally vulcanized. According to the present invention, it is possible to easily produce a compressed foam layer having micropores of 100 μm or less with an open cell ratio of 100%, and therefore, the produced printing blanket has no swelling of the blanket surface under printing pressure. can be absorbed evenly and reliably, making it possible to obtain clear prints. In addition, the rate of relaxation of compressive strain during high-speed printing becomes faster, making it possible to obtain clearer printing, which has the advantage of improving the durability of the plate cylinder or blanket. The present invention will be explained in more detail. First, when used in the present invention, a general rubber thermoplastic resin or a compound containing this rubber or this thermoplastic resin as a main component can be used as the polymer, but for the compressed layer of a printing blanket, printing ink can be used. And/or those with strong resistance to solvents used during ink replacement are preferred. For example, butadiene
It can be one or more of acrylonitrile copolymer, polyvinyl chloride, and chloroprene rubber. In addition to the main components such as rubber, vulcanizing agents such as sulfur, vulcanization accelerators, reinforcing agents such as carbon black, anti-aging agents, etc.
It may also be a compound obtained by adding and kneading a processing aid such as stearic acid. Next, as the solvent for dissolving this polymer, basically any solvent may be used as long as it can be dissolved in the gelling liquid. That is, since this gelling liquid is to be gelled by mutually diffusing with the solvent of the polymer solution, the solvent must mutually diffuse with the gelling liquid, which has a stronger affinity than the polymer. . Therefore, this solvent varies depending on the type of gelling solution, but generally one such as N,N-dimethylformamide, diethylformamide, dimethylacetamide, dimethylsulfoxide, etc.
It can be a species or a mixture of two or more species. The polymer is dissolved in this solvent, and the polymer concentration at this time is 2 to 70%. If it is outside this range, it will be difficult to apply glue, and workability will be significantly reduced. By adjusting the polymer concentration, the density of the foam can be changed from a high-density open cell to a low-density open cell. For example, if the polymer concentration is 30%, the specific gravity is 0.35-0.40
A foam of 60% is obtained with a specific gravity of 0.65
A foam of ~0.75 can be obtained. This is because, as will become clear from the manufacturing method described below, the pores are formed by mutual diffusion of the solvent and the gelling solution, and therefore the density changes depending on the polymer concentration. In the present invention, a surfactant having at least one functional group selected from sulfonic acid groups, ether groups, and hydroxyl groups or having an amine structure and/or silicone in an amount sufficient to have an antifoaming effect are added to the polymer solution. Added. This group of materials is added to facilitate pore size adjustment according to the polymer concentration described above. This is particularly effective when it is desired that the pores be of a desired size, that is, 10 μm or more. The pore size can be adjusted by changing the concentration of the above-mentioned polymer, the type of substance in this group, and the amount added. Examples of surfactants that are pore regulators include sodium dodecylbenzenesulfonate, Na di-alkyl sulfosuccinate, polyoxyethylene oleate, polyoxyethylene lauryl ether, polyoxyethylene octyl phenyl ether, polyoxy Examples include one or more of ethylene stearyl ether, dodecyl dimethylamine, and octadecyl amine; examples of silicone include
SAG-471, SAG-100 (manufactured by Nippon Unicar Co., Ltd.), SH-193 (manufactured by Toray Silicon Co., Ltd.), etc. can be used, but are not basically limited to these. The amount added can be functionally changed depending on the pore size, polymer concentration, type of surfactant and/or silicone, but in general, in order to create micropores of 100 μm or less,
It is preferable to add 20% or less. If more than 15% is added, the pore size becomes too large. Generally, when using an organic surfactant alone, preferably 0.1 to 15%
When silicone is used alone, it is preferably added in an amount of 0.1 to 20% or less. When surfactants and silicones are used in combination, it is preferred that the amounts correspond to those mentioned above. In the case of silicone, it is generally added as a foam stabilizer, but if the amount added is increased, it will have an antifoaming effect. For example, SH-
In the case of 193, when it is added in an amount of 5% or more, it has an antifoaming effect. For this reason, when silicone is added, it must be in an amount sufficient to provide an antifoaming effect, and if the amount of silicone added is less than 0.1%, the antifoaming effect will not be sufficient. Next, the composition of the present invention has an average length of 300 μm.
Powder crystals or cellulose of less than m are added. This is added in order to prevent coarsening of pores and non-uniformity of dimensions caused by various factors in manufacturing operations when manufacturing a printing blanket compressed layer. For example, when coating a base fabric with a composition, air may be drawn in and create pores of 100 μm or more, or the pores may become uneven due to variations in the method of adding the gelling liquid or the dipping temperature, or the formation of a thick foam layer. When extracting the solvent, it is possible to prevent coarse pores of 100 μm or more in the center of the foam layer from becoming coarse and non-uniform dimensions due to insufficient manufacturing control, and to facilitate manufacturing operations. It is something. Examples of such crystals or cellulose include one or a mixture of two or more of silica, calcium carbonate powder, wood valve, and synthetic fiber flock. The amount of crystals or cellulose added varies depending on the cohesive force caused by the polymer (including rubber and compounding agents) in the polymer solution, but is generally 30% or less based on the polymer solution. If it exceeds 30%, the pore size and uniformity stability will increase, but the produced compressed layer will become too hard, making it undesirable as a compressed layer for printing blankets. The average length of this crystal or cellulose is 300 μm or less. This is because if the length exceeds 300 μm, coarse pores exceeding 100 μm will occur corresponding to the length. The preferred average length of the crystals or cellulose is determined by the combination of polymers (ie, the relationship of collective force). For example, in the case of a polymer made by blending 50 parts of carbon black (reinforcing filler) with butadiene-acrylonitrile copolymer (Hiker 1042; manufactured by Zeon Corporation), MT carbon black has a diameter of 45 μm or less, SRF carbon black has a diameter of 90 μm or less, 150 in HAF carbon black
It is preferable to use a material with an average length of μm or less.
This is because if fibers with an average length longer than this are used, coarse pores will be produced. The gelling liquid that is then added to the polymer solution is a liquid that is insoluble in the polymer but soluble in the solvent. This is to selectively elute the solvent from this polymer solution as described above, and therefore the liquid is such that the affinity between the solvent and the gelling liquid is greater than the affinity between the solvent and the polymer. . Basically, there are no limitations as long as it is like this. For example, it can be one or a mixture of two or more of water, monools such as methanol and ethanol, and polyols such as glycerin and ethylene glycol. The amount of this gelling solution added is 20 to 95% of the amount of gelling solution.
It is. Here, the amount of gelling liquid refers to the amount of gelling liquid required for the polymer solution to reach the gelling point. This gelling liquid is added to increase the elution rate of the solvent when forming a compressed layer, thereby increasing the film formation rate and generating pores with a fine cell structure. The amount of liquid
If it is less than 20%, large-sized pores and small-sized pores coexist, and if it exceeds 95%, the polymer solution partially gels, making sizing impossible. This composition will be used to manufacture the compressed layer of a printing blanket, and the manufacturing method will be explained. First, the above-described composition is coated on a base fabric such as cotton, polyester, or nylon. This base fabric is basically not limited in the present invention, and the method of coating is not similarly limited. For example, as a coating method, a doctor knife, a roll coater, etc. may be used. Next, the base fabric coated with this composition is immersed in a gelling solution. The gelling liquid in this case may be the same as the gelling liquid contained in the composition, or may be different. For example, the gelling liquid contained in the composition can be alcohol and the gelling liquid in the immersion bath can be water, or vice versa, but considering economics etc., it is possible to use an immersion bath. It is preferable to use inexpensive water as the gelling liquid. Furthermore, the gelling liquid contained in the composition and the gelling liquid in the immersion bath may be the same. For example, both the gelling liquid in the composition and the gelling liquid in the immersion bath may be water. When the base fabric is immersed in the gelling liquid in this manner, the solvent in the composition and the gelling liquid mutually diffuse and form a gel. This is because the affinity between the gelling liquid and the solvent is greater than the affinity between the polymer and the solvent, so the polymer is in an undissolved state rather than a dissolved state, and the polymers coagulate and aggregate together. At this time, spaces are created in areas other than the agglomerated and aggregated polymer parts. This becomes micropores, and since the micropores generated in this way are caused by the mutual diffusion of the polymer solvent and gelling liquid, they are considered to be 100% completely continuous pores. . Furthermore, although it is clear that such micropores are generated at the gel point, unless the composition contains 20 to 95% of the gelling liquid, the gelation of the solvent and immersion bath will occur. Liquids do not quickly diffuse into each other,
Because the semi-gel state lasts for a long time, the formed membrane becomes weak during the pore generation process, and the pore walls become easy to tear, decreasing the stability of the pores, increasing the size of the pores, and increasing the size of the pores. It becomes inconsistent. According to the present invention, since the composition contains a gelling liquid in advance (that is, it contains a gelling liquid close to gelling), it quickly gels when immersed in the gelling liquid, and the walls of the pores form a gel. Increases strength in a short time. In other words, fine pores with stable dimensions can be formed. This gelling solution for dipping may be at room temperature, but may also be heated to further accelerate the gelling rate. For example, add 50% of this gelling solution.
The temperature may be kept at about 100°C. In this case, the pores become even finer. The thus gelled product is desolventized, dried, for example, in a hot air dryer at 100 to 160°C for 20 minutes or more, and simultaneously vulcanized. In the case of a thermoplastic elastomer, vulcanization is not necessary, so it may be dried for about 30 minutes at a temperature of 150° C. or lower, for example. Of course, the drying method, drying time, drying temperature, etc. are not limited in the present invention. It can be determined functionally by considering the type of composition and the like. The foamed layer thus produced is provided with the necessary number of base fabrics and surface rubber layers by a conventional method to obtain a printing blanket. Examples of the present invention will be described below. Example 1 Composition Group A butadiene/acrylonitrile copolymer
100 parts by weight (Hiker 1042; manufactured by Zeon Corporation) Zinc white 5 Stearic acid 1.0 Carbon black (SRF) 50 Anti-aging agent 1.0 Total 157 Group B fiber flock (average length 30 μm) 3.0 parts by weight Silica 1.0 Antifoaming agent (SAG) -471; Manufactured by Nippon Unica Co., Ltd.)
1.0 Total 5.0 Group C sulfur Yellow 1.5 parts by weight Vulcanization accelerator 3.0 Total 4.5 Group D Dimethylformamide: water = 1:1 {weight ratio) The compounding ingredients of Group A were kneaded with a roll, and the rubber content was 40% in dimethylformamide. When dissolved, a polymer solution with a viscosity of 450 poise was obtained.
Add group B cellulose to this, stir thoroughly, add group C vulcanizing agent and vulcanization accelerator, and then add a dimethylformamide:water = 1:1 solution to the polymer solution.
Add at a ratio of 8g to 100g while stirring thoroughly. The composition made in this way has a thickness of 0.41 mm.
It was coated with a doctor knife to a thickness of 0.35 mm on a cotton cloth with a number of strokes of 61 lines/inch. this
After being immersed in water at 18°C for 20 minutes, the water was drained and dried in a dryer at 150°C for 20 minutes, at the same time completing vulcanization. Photographs of the cross section of this foam are shown in FIGS. 1 and 2. FIG. 1 is a 75x photomicrograph of a compressed printing blanket layer according to the invention, and FIG. 2 is a 150x photomicrograph according to the invention. For comparison, a 75x micrograph of a compressed layer made using a conventional organic blowing agent is shown in Figure 3.
As is clear from these photographs, the compressed layer according to the present invention mostly consists of micropores of 25 μm or less and has an open cell ratio of 100%, whereas the compressed layer manufactured by the conventional method is non-uniform. There were many large pores exceeding 100 μm in size. A composition similar to the composition according to the invention described above is then prepared with powdered crystals and cellulose and an antifoam agent (i.e. B
A compressed layer was manufactured in the same manner as described above using the composition except for group). A 150x micrograph of these compressed layers is shown in FIG. As is clear from Figure 4, when powder crystals, cellulose, and antifoaming agents were not included, most of the parts had micropores of 25 μm or less and an open cell ratio of 100%.
It can be seen that there are large pores exceeding 100 μm. This may be caused by air being drawn in when coating the composition with a doctor knife as mentioned above, or may be caused when extracting the solvent when producing a thick compressed layer, or it may be caused by the composition of the gelled liquid. This is thought to be caused by the method of addition to the water or variations in the immersion temperature. The composition according to the present invention does not require strict control of the process and does not produce the above-mentioned coarse pores. FIG. 5 is a 25x micrograph of a compressed layer made with a composition other than the antifoam agent and fiber flock described above. Also in this case, coarse pores are generated. A partially enlarged micrograph (75x) of this compressed layer is shown in FIG. As is clear from Figures 5 and 6, when no antifoaming agent is included, extremely fine pores (10μ
m or less). Figure 7 is a 75x microscopic photograph of a compressed layer made with a composition containing only an antifoaming agent, and compared to Figure 6, the micropores have become larger due to the addition of the antifoaming agent. I understand.
Comparing Figure 1 and Figure 7, the holes in Figure 7 are somewhat irregular and inconsistent, whereas
In the case of FIG. 1, it is constant, and in FIG. 7, large pores of 100 μm or more were partially formed. This did not occur with the compressed layer according to the invention. Next, a compressed layer was produced in the same manner using a composition having the same composition, but to which no gelling liquid (water) had been added in advance. A 75x microscopic photograph of the compressed layer in this case is shown in FIG. 1st
8 and 2, the holes in FIG. 8 are distributed over a wide range from large holes to small holes, and it can be seen that it is difficult to obtain uniform performance. Example 2 A compressed layer according to the present invention manufactured using a composition according to the table below, a compressed layer manufactured using an organic blowing agent (Utility Model Publication No. 18242/1983), and a compressed layer manufactured by mixing hollow microspheres into an elastomer. (Tokuko Showa 52-7371
A compressive stress-strain curve test was conducted using a printing blanket manufactured using the following method. The results are shown in Figure 9.

【table】

[Table] As is clear from FIG. 9, the blankets C ₁ , C ₂ , C ₃ , and C ₄ of the present invention are Blanket A, which has a conventional compressed layer in which micro hollow spheres are mixed into an elastomer, and Blanket A, which has a compressed layer in which micro hollow spheres are mixed into an elastomer. Blanket B manufactured using
showed an extremely superior stress-strain curve. When printing tests were conducted using these blankets, it was found that the halftone dot reproducibility was excellent and the durability was 2 to 3 times higher than that of the blanket A. This is thought to be because the strain rate is much higher for the same compression force than the conventional blankets A and B, and the compression layer has the ability to sufficiently cope with the deformation load.

[Brief explanation of the drawing]

Figure 1 is a 75x micrograph of a printing blanket compressed layer in one embodiment of the present invention, and Figure 2 is a micrograph of the compressed layer for printing.
This is a 150x micrograph. Figure 3 is a 75x micrograph of a conventional compressed layer using an organic blowing agent. Figure 4 is a 150x micrograph of a cross-section of a compressed layer produced from the composition of the present invention except for the powder crystals, cellulose, and antifoaming agent, and Figure 5 is the powder crystal mass from the composition of the present invention. FIG. 6 is a 25x micrograph of a compressed layer made with the composition excluding cellulose and antifoaming agent, and FIG. 6 is a 75x micrograph thereof. FIG. 7 is a 75x micrograph of a compressed layer prepared from the composition of the present invention without the fiber flock. FIG. 8 is a 75x micrograph of a compressed layer made from the composition of the present invention without the addition of a gelling liquid. FIG. 9 is a graph showing the stress-strain ratio of a printing blanket manufactured according to the present invention and a conventional printing blanket. A... A stress-strain graph of a printing blanket with a compressed layer manufactured by mixing micro hollow spheres in an elastomer. B... Stress-strain rate graph with a compressed layer manufactured using an organic foaming agent.
C ₁ , C ₂ , C ₃ , C ₄ ... Stress-strain rate graph with a compressed layer produced by the method according to the present invention.

Claims (1)

[Scope of Claims] 1 A polymer solution prepared by dissolving a polymer in a solvent at a polymer concentration of 2 to 70% has at least one functional group selected from sulfonic acid groups, ether groups, and hydroxyl groups, or has an amine structure. In addition to adding one or more surfactants and/or a sufficient amount of silicone to exhibit an antifoaming effect, powder crystals with an average length of 300 μm or less and/or
Alternatively, 30% or less of cellulose is added to the polymer solution, and 20% or less of cellulose is added in an amount necessary for the polymer solution to gel with a gelling liquid that is soluble in the solvent of the polymer solution but not soluble in the polymer.
A composition for producing a compressed layer of a printing blanket consisting essentially of ~95% addition. 2. The composition for producing a compressed layer of a printing blanket according to claim 1, wherein the polymer is a rubber or a thermoplastic resin, or a compound containing the rubber or thermoplastic resin as a main component. 3. The composition for producing a compressed layer of a printing blanket according to claim 2, wherein the polymer is resistant to printing ink and/or solvents used during ink change. 4. A patent claim characterized in that the polymer is a butadiene/acrylonitrile copolymer polyvinyl chloride, chloroprene rubber, or a compound containing one or more of the butadiene/acrylonitrile copolymer, polyvinyl chloride, and chloroprene rubber as main components. A composition for producing a compressed layer of a printing blanket according to Scope 3. 5. The solvent is selected from N,N'-dimethylformamide, diethylformamide, dimethylacetamide and dimethylsulfoxide.
The composition for producing a compressed layer of a printing blanket according to any one of claims 1 to 4, characterized in that the composition comprises one or more types. 6. The composition for producing a compressed layer of a printing blanket according to any one of claims 1 to 5, characterized in that 20% or less of the surfactant and/or the silicone is added. 7. The composition for producing a compressed layer of a printing blanket according to claim 6, wherein when the surfactant is added alone, the amount added is 0.1 to 15%. 8. The composition for producing a compressed layer of a printing blanket according to claim 6, wherein when the silicone is added alone, the amount added is 0.1 to 20%. 9. The printing according to any one of claims 1 to 8, wherein the powder crystal and/or cellulose is one or a mixture of two or more of silica, calcium carbonate, wood pulp, and synthetic fiber flock. A composition for producing a compressed layer of a blanket. 10. The compressed layer of a printing blanket according to any one of claims 1 to 9, wherein the gelling liquid is one or more selected from the group consisting of water, monools, and polyols. Composition for manufacturing. 11. The composition for producing a compressed layer of a printing blanket according to claim 10, wherein the gelling liquid is water. 12 Polymer in solvent with polymer concentration of 2 to 70%
One or more surfactants having at least one functional group among sulfonic acid groups, ether groups, and hydroxyl groups or having an amine structure and/or exhibiting antifoaming action are added to the dissolved polymer solution. Add a sufficient amount of silicone to the polymer solution, and add powder crystals and/or cellulose with an average length of 300 μm or less to the polymer solution.
30% or less, and further add a gelling liquid that is soluble in the solvent of the polymer solution but not soluble in the polymer in an amount of 20 to 95% of the amount necessary for the polymer solution to gel. Coating a composition for producing a compressed layer of a printing blanket on a base fabric,
A method for producing a compressed layer for printing blankets, which comprises immersing the layer in a gelling solution, removing the solvent, drying and, if desired, vulcanizing. 13. The method for producing a compressed layer of a printing blanket according to claim 12, wherein the polymer is a rubber or a thermoplastic resin, or a compound containing the rubber or thermoplastic resin as a main component. 14. A method for producing a compressed layer of a printing blanket according to claim 13, characterized in that the polymer is resistant to printing inks and/or solvents used during ink changes. 15. A patent claim characterized in that the polymer is one or more of butadiene/acrylonitrile copolymer polyvinyl chloride and chloroprene rubber, or a compound containing one or more of these copolymers polyvinyl chloride and chloroprene rubber as a main component. A method for manufacturing a compressed layer of a printing blanket according to Scope 14 of 16 The solvent is 1 selected from N,N'-dimethylformamide, diethylformamide, dimethylacetamide and dimethylsulfoxide.
16. A method for producing a compressed layer of a printing blanket according to any one of claims 12 to 15, characterized in that the solvent is a species or two or more kinds of solvents. 17. The method for producing a compressed layer of a printing blanket according to any one of claims 12 to 16, characterized in that the surfactant and/or the silicone is added in an amount of 20% or less. 18. A method for producing a compressed layer of a printing blanket according to claim 17, characterized in that when the surfactant is added alone, the amount added is 0.1 to 15%. 19. The method for producing a compressed layer of a printing blanket according to claim 17, wherein when the silicone is added alone, the amount added is 0.1 to 20%. 20. The printing according to any one of claims 12 to 19, wherein the powder crystal and/or cellulose is one or a mixture of two or more of silica, calcium carbonate, wood pulp, and synthetic fiber flock. Method for manufacturing compressed layers for blankets. 21 Claim 1, wherein the gelling liquid is one or more selected from water, monools, and polyols.
2. A method for producing a compressed layer of a printing blanket according to any one of 2 to 20. 22. A method for producing a compressed layer of a printing blanket according to claim 21, characterized in that the gelling liquid contained in the composition and/or the gelling liquid in the immersion bath is water.