JP3146599B2 - Surface modification method of printing blanket and printing blanket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a printing blanket.
(Hereinafter, referred to as printing material) surface modification method and stamp material, yet while maintaining the characteristics of the stamp material surface layer in particular, it relates to a surface modification method and stamp material of the stamp material which ink transfer and to improve the paper peeling property.

[0002]

2. Description of the Related Art An offset printing press comprises a plate cylinder 1 on which a plate serving as a document is wound, and a printing material cylinder 2 which rotates in conjunction with the plate cylinder 1.
And an impression cylinder 4 for holding the printing paper 3 under pressure, together with the printing material cylinder 2. A printing material 5 is wound around the printing material cylinder 2. A method in which ink is attached to a plate cylinder wound around the plate copper 1, an image formed by the ink is temporarily transferred to a printing material 5 of a printing material cylinder 2, and the transferred image is printed on a printing paper 3 to be in contact with the printing material 3. It is.

[0003] The printing material 5 used in such a printing machine is as follows.
As shown in FIG. 2, a compression layer 52 of an elastic material is generally formed on a base cloth 51 as necessary, and a surface layer 53 is further formed on the compression layer 52.
Are in contact with the surface layer 53.

[0004] One problem in using the above-described stamping material 5 is that the rubber of the surface layer 53 is immersed in oil-based printing ink. For this reason, for example, conventionally as the surface layer,
Instead of using low-nitrile acrylonitrile-butadiene rubber having excellent printability (such as ink transferability) but poor oil resistance, acrylonitrile-butadiene rubber having a medium and high nitrile having good oil resistance is used. However,
Acrylonitrile butadiene rubber having a middle and high nitrile as described above has a problem in that although it has good oil resistance, it has problems in ink transferability and paper releasability.

In order to improve the oil resistance, there is known a stamping material obtained by curing and coating, for example, an ethylene tetrafluoride-propylene copolymer (Japanese Utility Model Publication No. 55-38682).
In such a device, the surface layer is basically covered with an oil-resistant film. However, since the film is basically covered, a phenomenon such as film peeling cannot be avoided. There is a drawback that the properties and paper separation properties are not considered.

Further, there has been an attempt to reduce the adhesive strength of the ink to the surface layer to improve the ink transferability, and a printing material having a coating film in which the critical surface tension of the surface layer is controlled to 18 to 25 dyne / cm. Is also known (Japanese Patent Publication No. 56-3)
No. 6077). However, it has been known that the acceptability of the ink and the transferability of the ink to paper do not simply depend on the critical surface tension.

It is also known that a surface-modifying composition obtained by diluting a surface modifier having a perfluoroalkyl group and having a critical surface tension of 10 to 16 dyne / cm with a solvent is applied to the surface of a printing blanket. (JP-A-4-128)
No. 95). However, although the initial printability (ink transfer property, paper releasability, etc.) is good by simply applying it to the surface of a printing blanket, their durability (abrasion resistance) is assumed when used for a long time. Properties, scratch resistance, etc.)
Is insufficient.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the printing material described in Japanese Patent Application Laid-Open No. 4-12895 and to maintain the properties of the printing material surface layer while maintaining the properties of the printing material. It is an object of the present invention to provide a method for modifying the surface of a printing material and a printing material having a durability capable of maintaining these properties for a long period of time, as well as improving transferability and paper separation.

[0009]

The inventors of the present invention have made intensive studies in view of the above-mentioned situation, and found that a printing material surface layer coated with a synthetic resin (I) having a fluorinated alkyl group on the surface of a printing blanket rubber was coated. When a mixture of a synthetic resin (I) having a specific fluorinated alkyl group and a rubber for a printing blanket was used for the surface layer instead of using as a surface layer, it was found that an extremely durable printing material was obtained. Was completed.

That is, the present invention provides a stamping material characterized by having a surface layer of a mixture of a synthetic resin (I) having a specific fluorinated alkyl group and a rubber, specifically, two or more fluorinated alkyl groups in one molecule. The present invention relates to a stamping material characterized by having a surface layer containing a rubber containing at least one ethylenically unsaturated monomer (A) and / or α, β-ethylenically unsaturated monomer (B). In a method of manufacturing a stamping material by bonding a surface layer and a layer provided with a compression layer of an elastic body on a cloth and a base cloth as required, a method for producing the stamp material, wherein the specific fluorinated alkyl group is used as a surface layer. A method for producing a stamping material, which comprises using a mixture of resin (I) and rubber, and further adding and kneading the synthetic resin (I) having a specific fluorinated alkyl group as a surface layer to rubber, followed by vulcanization and chlorination. Using the mixture Method for producing a stamp material according to claim Rukoto,
Specifically, an ethylenically unsaturated monomer (A) having two or more fluorinated alkyl groups in one molecule and / or α,
The present invention relates to a method for producing a stamp material, characterized in that a rubber containing a β-ethylenically unsaturated monomer (B) is provided in a surface layer.

The synthetic resin (I) having a fluorinated alkyl group, which is a surface modifier for a stamping material according to the present invention, has a fluorinated alkyl group having water and oil repellency as a main component.
Even if the surface tension is small, there is an advantage that it has good ink receptivity and oil resistance, and can improve the ink transfer property and the paper releasability. In addition, instead of forming a coating layer on the surface layer as in the related art, or simply wiping the surface of the existing printing material with a surface modifier, a synthetic resin (I) having a fluorinated alkyl group is added and kneaded. The use of rubber as the surface layer has the advantage of improving the printing performance durability (abrasion resistance, scratch resistance, etc.) for long-time use, which could not be improved until now, as well as the limit use capacity of the printing material Can be extended as compared with the conventional case, and there is a great advantage in terms of economy.

Furthermore, since the surface modifier stays on the surface of the stamp material to prevent the colored particles of the printing ink from entering the inside of the rubber material of the stamp material, an effect of eliminating the residual of the former plate is also produced. In addition, during multicolor printing, when a previously printed color is printed on paper for the next color, the phenomenon that the next color is reverse-transferred to the surface of the stamping material that prints the next color and contaminates the printing color, a so-called reverse trapping phenomenon, It also has the effect of preventing.

This surface modifier is a substance having a fluorinated alkyl group as a functional group. Such a substance having a fluorinated alkyl group has a low surface tension, has water and oil repellency, and is characterized by being hardly soluble in water, IPA and petroleum solvents used for printing. . In addition, the ink acceptability is good, and printing is not hindered despite the low surface tension.

In the present invention, an ethylenically unsaturated monomer (A) having two or more fluorinated alkyl groups in one molecule is contained as an essential component constituting the synthetic resin (I) having a fluorinated alkyl group. This not only improves the ink transfer and paper release properties while maintaining the properties of the printing material surface layer, but also durability such as abrasion resistance and abrasion resistance, which are important for maintaining these properties for a long time. It is extremely important to improve the printing quality and to exhibit sufficient printing characteristics with an appropriate fluorine content from an economic viewpoint.

The following are examples of the ethylenically unsaturated monomer (A) having two or more fluorinated alkyl groups in one molecule. General formula

[0016]

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Wherein Rf is a fluorinated alkyl group having 1 to 20 carbon atoms, and X and Y are 1 or 2. ]

[0018]

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[Where Rf is the same as above;
f 'is a fluorinated alkyl group having 1 to 20 carbon atoms;
And Z 'is _{- (CH 2) X -,} - CH 2 CH (OH) (C
_{H 2) X -, - (} CH 2) X N (R 1) SO 2 -, - (C
_{H 2) X N (R 1} ) CO- ( the same as where X is the, R ₁ is H or an alkyl group having 1 to 6 carbon atoms),
_{-CH (CH 3) -, -} CH (C 2 H 5) -, - C (C
_{H 3) 2 -, - CH} (CF 3) - or - (CF _{3) 2} - a divalent linking group such as, R and R 'is H or F. ]

[0020]

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[Where Rf, Rf ', Z and Z' are the same as above, and R ₂ is H, Cl, CH ₃ , F or-(C
H ₂ ) _X Rf (where X and Rf are the same as above). ] As the ethylenically unsaturated monomer (A) having two or more fluorinated alkyl groups in one molecule,
It has two monovalent groups containing a fluorinated alkyl group, all of which have a skeleton bonded to the same carbon atom, and one of the monovalent groups containing the fluorinated alkyl group has a carbon atom and a fluorine atom. And those having a polar atomic group between the functionalized alkyl group, and when this structure is schematically shown,

[0022]

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Among them, a skeleton having at least two monovalent groups containing a fluorinated alkyl group, all of which are bonded to the same carbon atom or nitrogen atom is represented by (1). It is a skeleton. Three monovalent groups bonded to carbon atoms of the skeleton shown in (1) (in the above figure,

[0024]

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Among the monomers (A) according to the present invention, the monomer represented by the above general formula (A-4) has a polar atomic group in order to maintain compatibility with acrylonitrile butadiene rubber. However, from the viewpoint of oil resistance, ink acceptability, ink transferability, paper separation, abrasion resistance, abrasion resistance, and economic efficiency, for example, a polar atom may be present in the skeleton of (1). It is preferable to have 2 to 6 groups, among which 2 to 2 polar atomic groups in the skeleton of (1).
It is preferable that the monovalent group having 6 and having a fluorinated alkyl group have 1 to 2 polar atomic groups.

[0026]

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The polar group may be directly bonded to the fluorinated alkyl group or indirectly through another divalent linking group. The type of the polar atomic group is not particularly limited, and examples thereof include an ester bond (—C0O—) and urethane.
(-NHC00-) and the like. In particular, when a high degree of compatibility with acrylonitrile butadiene rubber, ink transfer property, paper releasability, etc. are developed, it is preferable to select a urethane bond as the polar atomic group.

The portion excluding the skeleton of (1) in the above figure is a group having a polymerizable α, β-ethylenically unsaturated double bond. The other structure of the group is not particularly limited as long as it has polymerizability, but when the skeleton of (1) is exactly the same, α, β-ethylenically unsaturated double is used. Those having a urethane bond or an ester bond in the group having a bond are more compatible with acrylonitrile butadiene rubber of the obtained polymer, ink transferability,
The paper releasability and the like tend to be further improved.

The monomer (A-4) according to the present invention includes:
For example, the general formula

[0030]

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Wherein Rf, Z and R ₂ are the same as above, and A is R ₃ C (CH ₂ —) ₃ (where R ₃ is H, methyl, ethyl or nitro) .) Or N (CH
₂ CH ₂ ) ₃ —, a trivalent linking group represented by N (CH ₂ CH (CH ₃ )) ₃ —, and B represents —OCONHY ₁ NHCO
O- (wherein, Y ₁ is a divalent linking group having 15 or less carbon atoms and occupying 35 to 65% by weight of D). And Z ₁ is-(C
H ₂ ) _m- (where m is an integer of 2 to 6) or -C
H ₂ CH (CH ₃₎ - is. ] It is a compound represented by these.

In the formula (A-5), two Zs may be different types of linking groups selected from the group of divalent linking groups. Representative examples of the Y ₁ group in the divalent linking group B include:

[0033]

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And the like. Also the general formula

[0035]

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[Wherein Rf, Rf ', Z, Z', Z ₁ ,
R is the same as described above, and X ₁ , X ₂ , and X ₃ are —O
COCH ₂ CH (R ₄ ) COO— (where R ₄ is H or an alkyl or alkenyl group having 1 to 36 carbon atoms) or

[0037]

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Is a divalent linking group selected from the group consisting of: A ₁ is R ₅ C (CH ₂ OCH ₂ CH (OH) CH ₂ )
_3- , R ₅ C (CH ₂ OCH ₂ CH ₂ OCH ₂ CH (OH) C
H _{2) 3} -. (Where, R ₅ is H, hydroxymethyl group, a methyl group, an ethyl group, or a nitro group), N (CH _{2
CH 2 OCH 2 CH (OH)} CH 2) 3 -, or N (CH ₂
CH (CH ₃ ) OCH ₂ CH (OH) CH ₂ ) ₃ — is a trivalent linking group. ), A compound represented by the general formula

[0039]

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[Wherein Rf, Rf, Z, Z 'and R
Is the same as above, and X ₄ and X ₅ are -C00-, -OCO
CH ₂ CH (R ₄ ) COO— (where R ₄ is the same as above),

[0041]

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Or a divalent linking group represented by —OCONHY ₁ NHCOO— (where Y ₁ is the same as described above). ) Is a divalent linking group selected from A compound represented by the general formula:

[0043]

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Wherein Rf, Rf ′, Z, Z ₁ and R are the same as above, and Rf ″ is Rf or Rf ′
And Z ″ is the same as Z or Z ′, and they may be the same or different, and X ₆ , X ₇ , X ₈
May be the same or different and may be -O- or -OCON
HY ₁ NHCOO- (where Y ₁ is the same as above)
X ₉ is —OCONH
A divalent linking group represented by Y ₁ NHCOO— (where Y ₁ is the same as described above) or —OCONH (CH ₂ ) _a — (where a is an integer of 0 to 2) And Z ₁ is the same as described above. ] It is a compound represented by these.

Specific examples of the monomer (A) include, for example, the following, but it is a matter of course that the present invention is not limited by these specific examples.

[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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[0056]

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[0057]

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[0058]

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[0059]

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The polymer (I) according to the present invention may be a homopolymer of the above-mentioned monomer (A), or may be used to obtain more excellent oil resistance, ink transferability, paper separation and the above-mentioned durability. In order to further enhance the compatibility with the rubber constituting the surface layer, other conventionally known fluorine-based monomers such as a fluorinated alkyl group-containing (meth) acrylate compound (A ′) and And / or a copolymer with a non-fluorinated α, β-ethylenically unsaturated monomer (B). Examples of the fluorinated alkyl group-containing (meth) acrylate compound (A ′) include the following. A'-1 CH ₂ = CHCOOCH ₂ CF ₃ A'-2 CH ₂ = CHCOOCH ₂ CF ₂ CF ₃ A'-3 CH ₂ = CHCOOCH ₂ CFHCF ₃ A'-4 CH ₂ = C (CH ₃ ) COOCH ₂ CFHCF ₃ A'-5 CH ₂ = CHCOOCH ₂ CH ₂ CF ₃ A'-6 CH ₂ = CHCOOCH ₂ CF ₂ CFHCF ₃ A'-7 CH ₂ = CHCOOCH ₂ CF (CF ₃ ) CF ₃ A'-8 CH ₂ = CHCOOCH (CF ₃ ) ₂ A'-9 CH ₂ = C (F) COOCH (CF ₃ ) ₂ A'-10 CH ₂ = C (CH ₃ ) COOCH (CF ₃ ) ₂ A'-11 CH ₂ = CHCOOCH ₂ (CF ₂ CF ₂ ) ₂ H A′−12 CH ₂ = C (F) COOCH ₂ (CF ₂ CF ₂ ) ₂ H A′−13 CH ₂ = C (CH ₃ ) COOCH ₂ (CF ₂ CF ₂ ) ₂ H A'-14 CH ₂ = CHCOOCH ₂ CF ₂ CF ₂ CFHCF ₃ A'-15 CH ₂ = CHCOOCH ₂ CF ₂ CF ₂ H A'-16 CH ₂ = C (CH ₃ ) C00CH ₂ CF ₂ CF ₂ H A '-17 CH ₂ = C (F) C00CH ₂ CF ₂ CF ₂ H A'-18 CH ₂ = CHCOOCH ₂ CH ₂ C ₈ F ₁₇ A'-19 CH ₂ = C (CH ₃ ) COOCH ₂ CH ₂ C ₈ F ₁₇ A'-20 CH ₂ = CHCOOCH ₂ CH ₂ C ₁₂ F ₂₅ A'-21 CH ₂ = C (CH ₃ ) COOCH ₂ CH ₂ C ₁₂ F ₂₅ A'-22 CH ₂ = CHCOOCH ₂ CH ₂ C ₁₀ F ₂₁ A'-23 CH ₂ = C (CH ₃ ) COOCH ₂ CH ₂ C ₁₀ F ₂₁ A'- 24 CH ₂ = CHCOOCH ₂ CH ₂ C ₆ F ₁₃ A′−25 CH ₂ = C (CH ₃ ) COOCH ₂ CH ₂ C ₆ F ₁₃ A′−26 CH ₂ = CHCOOCH ₂ CH ₂ C ₄ F ₉ A′− 27 CH ₂ = C (F) COOCH ₂ CH ₂ C ₆ F ₁₃ A'-28 CH ₂ = CHCOOCH ₂ (CH ₂ ) ₆ CF (CF ₃ ) ₂ A'-29 CH ₂ = CHCOOCH ₂ (CF ₂ ) ₆ HA′-30 CH ₂ = CHCOOCH ₂ (CF ₂ ) ₈ HA′−31 CH ₂ = C (CH ₃ ) COOCH ₂ (CF ₂ ) ₈ HA ′ 32 CH ₂ = CHCOOCH ₂ (CF ₂ ) ₁₀ H A'-33 CH ₂ = CHCOOCH ₂ (CF ₂ ) ₁₂ H A'-34 CH ₂ = CHCOOCH ₂ C (OH) HCH ₂ C ₈ F ₁₇ A'-35 CH ₂ = CHCOOCH ₂ CH ₂ N (C ₃ H ₇ ) SO ₂ C ₈ F ₁₇ A'-36 CH ₂ = CHCOOCH ₂ CH ₂ N (C ₂ H ₅ ) COC ₇ F ₁₅ A'-37 CH ₂ = CHCOO (CH ₂ ) ₂ (CF ₂ ) ₈ CF (CF ₃ ) ₂ Of course, the present invention is not limited by these exemplified compounds.

On the other hand, examples of the α, β-ethylenically unsaturated monomer (B) include styrene, nuclear-substituted styrene, acrylonitrile, vinyl chloride, vinylidene chloride, vinylpyridine, N-vinylpyrrolidone, vinylsulfonic acid,
Fatty acid vinyls such as vinyl acetate, and α, β-ethylenically unsaturated carboxylic acids, ie, mono- or divalent carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and α, β- As a derivative of an ethylenically unsaturated carboxylic acid, an alkyl group having 1 to 18 carbon atoms,
(Meth) acrylic acid alkyl ester (hereinafter, this expression is a generic term for both acrylic acid alkyl ester and methacrylic acid alkyl ester), that is, (meth)
Acrylic acid methyl, ethyl, propyl, butyl, octyl, 2-ethylhexyl, decyl, dodecyl, stearyl ester, etc., and (meth) acrylic acid having 1 to 1 carbon atoms
18 hydroxyalkyl esters, ie, 2-hydroxyethyl ester, hydroxypropyl ester, hydroxybutyl ester, etc., and (meth) acrylic acid aminoalkyl esters having 1 to 18 carbon atoms, ie, dimethylaminoethyl ester, diethylaminoethyl ester, diethylamino Propyl ester, etc.
Acrylic acid having an ether oxygen-containing alkyl ester having 3 to 18 carbon atoms, such as methoxyethyl ester, ethoxyethyl ester, methoxypropyl ester, methyl carbyl ester, ethyl carbyl ester, butyl carbyl ester, etc. Glycidyl esters of (meth) acrylic acid, i.e., glycidyl methacrylate, glycidyl acrylate, etc., such as alkyl vinyl ethers of 18, such as methyl vinyl ether, propyl vinyl ether, dodecyl vinyl ether, etc.
In addition, macromonomers such as styrene macromonomer 4500 manufactured by Sartomer Co., Ltd., and NK ester M-230G manufactured by Shin-Nakamura Chemical Co., Ltd. may be used.

In the present invention, (meth) acrylic acid is a general term for both methacrylic acid compounds and acrylic acid compounds, and (meth) acrylate is a general term for both methacrylate compounds and acrylate compounds. Are generically referred to.

The method for producing the fluoropolymer (I) obtained by polymerizing the monomer (A) according to the present invention and, if necessary, the monomer (B) is not limited at all. The method can be produced by a solution polymerization method, a bulk polymerization method, an emulsion polymerization method, or the like based on a polymerization mechanism such as a radical polymerization method, a cationic polymerization method, or an anion polymerization method, but the radical polymerization method is particularly simple and industrial. Preferred. In this case, as the polymerization initiator, those known in the art can be used,
Examples thereof include peroxides such as benzoyl peroxide and diacyl peroxide, azo compounds such as azobisisobutyronitrile and phenylazotriphenylmethane, and metal chelate compounds such as Mn (acac) 3. Chain transfer agents such as lauryl mercaptan, 2-mercaptoethanol, ethylthioglycolic acid, octylthioglycolic acid,
Further, a thiol compound having a coupling group such as γ-mercaptopropyltrimethoxysilane can be used in combination with a chain transfer agent. The fluorine-based random or block copolymer according to the present invention can also be obtained by photopolymerization in the presence of a photosensitizer or a photoinitiator, or polymerization using radiation or heat as an energy source.

The polymerization can be carried out in the presence or absence of a solvent, but is preferably carried out in the presence of a solvent from the viewpoint of workability. As the solvent, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone, dimethyl ether, methyl ethyl ether, tetrahydrofuran, ethers such as dioxane,
Esters such as methyl acetate, ethyl acetate, and butyl acetate;
Polar solvents such as dimethylformamide and dimethylsulfoxide; chlorinated solvents such as chloroform, dichloroethane, 1,1,1-trichloroethane, perchloroethylene and carbon tetrachloride; and aromatic hydrocarbons such as toluene, xylene and benzene; Further, perfluorooctane, perfluorotri-
Any of the fluorinated inert liquids such as n-butylamine can be used.

The printability of the surface layer of the printing material, such as compatibility with acrylonitrile-butadiene rubber, oil resistance, ink acceptability, ink transferability, paper releasability, and durability, depends on the printing speed, required sharpness, and the like. The copolymerization ratio of various monomers can be arbitrarily determined according to the purpose of the stamping material to be produced from the differences, and particularly, the monomers (A) and (A ′) of the polymer (I) can be determined. ) And / or the copolymerization ratio with (B) is
The weight ratio is usually 100: 0 to 1: 1000, and 2:
The range of 1-1: 100 is preferable, and 49: 51-1: 1.
00 is preferable in terms of exhibiting various properties, oil resistance, ink transferability, and paper releasability of the surface layer of the printing material shown in the present invention, and further exhibits economic efficiency related to the fluorine content in the polymer (I). Especially preferred above.

The molecular weight of the fluoropolymer (I) according to the present invention is preferably Mn = 2,000 to 1,000,000, and particularly preferably Mn = 3,000 to 100,000. In the method for modifying the surface of a stamping material according to the present invention, the surface layer of the target stamping material may be basically any material as long as it is conventionally used as the surface layer of the stamping material, but is usually rubber.

The rubber used in the present invention includes, for example, natural rubber, neoprene rubber, ethylene propylene rubber, low-medium-high styrene butadiene rubber, methyl methacrylate butadiene rubber, methylstyrylene butadiene rubber, butadiene rubber, isoprene rubber, and low nitrile rubber. Acrylonitrile butadiene rubber, middle and high nitrile acrylonitrile butadiene rubber and the like can be effectively used.

Among the rubbers, when acrylonitrile butadiene rubber having a middle and high nitrile is used, the ink transfer property and the paper separation property can be remarkably improved. In other words, by using acrylonitrile butadiene rubber of medium and high nitrile, which has good oil resistance, but has poor ink transferability and paper releasability, it has good oil resistance, good ink receptivity, and good ink transferability and paper releasability. It can be used as a stamp material.

In the method for producing a stamp material according to the present invention, the amount of the synthetic resin (I) added to the rubber is not particularly limited, but 1 to 100 parts by weight per 100 parts by weight of rubber is good for oil resistance and ink. It is preferable from the viewpoint of developing transferability and paper separation.

In the method for manufacturing a stamp material according to the present invention, a known and commonly used bonding method such as heat fusion or use of an adhesive is used as a bonding method between the base fabric and the compressed layer formed as necessary and the surface layer. be able to.

[0071]

EXAMPLES Next, reference examples, examples and comparative examples will be given in order to explain the present invention in more detail. However, it is needless to say that the present invention is not limited by these descriptions. “Parts” in the text are based on weight unless otherwise specified. Reference Example 1 (Synthesis of fluorinated copolymer) 30 parts by weight of fluorinated monomer A-5-22 and 70 parts by weight of methyl methacrylate (hereinafter abbreviated as MMA) in a glass flask equipped with a stirrer, a condenser and a thermometer. Part, and methyl isobutyl ketone (hereinafter abbreviated as MIBK)
233 parts by weight of azobisisobutyronitrile (hereinafter referred to as A) as a polymerization initiator in a nitrogen gas stream under reflux.
After adding 1 part by weight of IBN) and 0.2 part by weight of lauryl mercaptan) as a molecular weight modifier, the mixture was refluxed for 7 hours to complete the polymerization. MIBK was completely removed from the obtained polymer solution by a rotary evaporator to obtain a pale yellow powder.

The molecular weight of this polymer in terms of polystyrene measured by gel permeation chromatography (hereinafter abbreviated as GPC) was Mn = 9,800. (This copolymer is referred to as polymer 1.) The polymer 1 was applied to a steel plate and dried, and then the critical surface tension was measured. As a result, 18.5 dyn was obtained.
e / cm. Reference Examples 2 to 6 Reference Example 1 except that the various fluorine-based monomers (A) and (A ′) and the non-fluorine-based monomer (B) were used in the proportions shown in Table 1.
In the same manner as described above, a fluorinated copolymer solution was obtained. Table 1 shows the molecular weight measurement results of these polymers and the results of the critical surface tension measured in the same manner as in Reference Example 1.

[0073]

[Table 1]

The abbreviations in the table indicate the following compounds. MMA: Methyl methacrylate IBMA: Isobutyl methacrylate SMA: Stearyl methacrylate β-HEMA: β-hydroxyethyl methacrylate Example 1 After providing a compression layer on a base cloth, the base was not formed as shown in the following composition. A mixture of vulcanized acrylonitrile butadiene rubber and the above polymer 1 was applied at 650 g / m ² and vulcanized to form a surface rubber layer.

Composition Middle and high nitrile NBR 100 Stearic acid 1 Zinc white 5 Filler 30 Sulfur 2 Vulcanization accelerator 3 Polymer 1 3 ■■■■■■■■■■■■■■■■■■■■ Total 144 ( Parts by weight) Examples 2 to 4 Copolymers 2 to 4 instead of Medium High Nitrile NBR and Polymer 1
A stamping material having a surface rubber layer was obtained in the same manner as in Example 1 except that each of No. 4 was mixed. Example 7 A polymer 1 (30 parts by weight) was dissolved in MIBK (70 parts by weight), and a solution obtained by adding 10 phr to a middle and high nitrile NBR in a toluene solution was applied. In the same manner, a stamp material having a surface rubber layer was obtained. Comparative Example 1 A stamping material having a surface rubber layer was obtained in the same manner as in Example 1 except that Polymer 1 was not mixed with acrylonitrile butadiene rubber. Comparative Example 2 A stamping material having a surface rubber layer formed thereon was obtained in the same manner as in Example 1 except that a surface rubber layer was formed in the same manner as in Comparative Example 1, and the polymer 5 was applied to the surface.

Using the printing materials obtained in Examples 1 to 4 and Comparative Examples 1 and 2, a Mitsubishi sheet-fed printing machine was used as a printing machine.
The 90th and 540th sheets when printing was performed on art paper at a printing speed of 90 sheets / min using commercial rotary printing ink as the ink.
Each of the 0th sheet was evaluated for ink transferability, paper releasability, and halftone dot reproducibility. The results are shown in Table 2.

Evaluation Criteria Ink transfer property and paper release property A: Excellent. ：: good Δ: somewhat good ×: poor halftone dot reproducibility ：: very small dot gain.

：: 〃 small △: 大 き い large ×: 〃 very large

[0079]

[Table 2]

[0080]

According to the method for modifying the surface of a stamping material and the stamping material of the present invention, a specific fluorinated material is used instead of using a stamping material surface layer in which a synthetic resin having a fluorinated alkyl group is applied to rubber and coated. Since a mixture of a synthetic resin having an alkyl group and rubber is used for the stamp material surface layer, there is an advantage that the ink transfer property and the paper releasability can be improved to higher levels as compared with the above-described stamp material. Moreover, such a printing material also has good ink acceptability and oil resistance as in the past.

That is, instead of forming a coating layer on the surface layer as in the prior art, or simply wiping the surface of an existing printing material with a surface modifier, a synthetic resin having a specific fluorinated alkyl group is added and kneaded. The durability of printing performance for long-time use (abrasion resistance, scratch resistance, etc.), which could not be improved until now, by using the obtained rubber as a surface layer
In addition to the advantage of improving the printing quality, the limit of use of the stamping material can be extended as compared with the prior art, and there is a great advantage in terms of economy.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a printing press.

FIG. 2 is a cross-sectional view illustrating an example of the structure of a stamp material.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 The plate cylinder which wound the plate used as a manuscript 2 The blanket cylinder 3 The printing paper 4 The impression cylinder 5 Synthetic resin which polymerized the ethylenically unsaturated monomer which has two fluorinated alkyl groups in one molecule as an essential component, Blanket 51 having a mixture obtained by vulcanizing and kneading nitrile NBR in the surface layer 51 Base cloth 52 Compressed layer 53 Synthetic resin obtained by polymerizing an ethylenically unsaturated monomer having two fluorinated alkyl groups in one molecule as an essential component Blanket surface layer consisting of a mixture obtained by vulcanizing and kneading middle and high nitrile NBR

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41N 10/00-10/04

Claims (4)

(57) [Claims] (1) two or more fluorinated alkyl groups per molecule;
Having an ethylenically unsaturated monomer (A) as an essential component
A printing blanket comprising a mixture of a synthetic resin (I) having a fluorinated alkyl group comprising a polymerized polymer and rubber in a surface layer. 2. A synthetic resin (I) comprising an ethylenically unsaturated monomer (A) having two or more fluorinated alkyl groups in one molecule and an α, β-ethylenically unsaturated monomer (B 2. The printing blanket according to claim 1, which is a copolymer obtained by polymerizing (1) and (2) as essential components. 3. A method for producing a stamping material by bonding a surface layer and a layer provided with a compression layer of an elastic material on a base cloth and, if necessary , a fluorinated alkyl group in one molecule as a surface layer.
An ethylenically unsaturated monomer (A) having two or more
A method for producing a printing blanket , comprising using a mixture of a synthetic resin (I) having a fluorinated alkyl group comprising a polymerized polymer as an essential component and rubber. 4. A fluorinated alkyl group in one molecule as a surface layer.
An ethylenically unsaturated monomer (A) having two or more
4. A blanket for printing according to claim 3, wherein a mixture obtained by adding and kneading a synthetic resin (I) having a fluorinated alkyl group consisting of a polymer polymerized as a component to acrylonitrile butadiene rubber and then vulcanizing and chlorinating is used. Production method.