JPH08276678A - Press plate material - Google Patents

Abstract

PURPOSE: To make a toner-deposited part repellent to a damping water and make parts other than the toner-deposited part hydrophilic by a monolayer sensitive material which uses a copolymer of a material having a metal-free phthalocyanine as a charge generator and a carboxylic acid group as a binder arranged on a conductive support body and a material having two vinyl groups. CONSTITUTION: A press plate material is made to be hydrophilic in reaction with a binder and a damping water having hydrophilicity by substituting a hydrogen atom of a carboxylic acid group included in the binder. In a series of a monolayer photosensitive body of a sensitive material and a binder having sensitivity to semiconductor laser or LED wavelength, a metal-free phthalocyanine is particularly used for the sensitive material. For the binder, a polymer of a material having a carboxylic acid group shown in the formula I and a series having two sets of vinyl groups shown in the formula II is used. Or a copolymer of a series having vinyl groups shown in the formulas III-VI is used in addition to the formulas I and II. In the formulas, R represents a carbon atom-containing alkyl group or a hydrogen atom, (c) represents a benzene ring, and R' represents a 1-4C alkyl group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive material of a printing base plate (hereinafter referred to as a simple printing plate) for light printing using an electrophotographic process, and more particularly to a simple printing plate prepared by a hydrophilic method using a fountain solution. It relates to printing plate materials.

[0002]

2. Description of the Related Art Conventionally, in the case of producing a simple printing plate, a recorded matter stored in a storage medium such as a personal computer is once hard-copied by an electrophotographic recording system or a photographed one is used as an original. A plate was prepared by charging, exposing and fixing zinc oxide master paper based on the original.

The disclosure regarding these is disclosed, for example, in JP-A-57 / 57.
-202544 and JP-A-58-68046.

However, this method has a problem in that the plate cannot be directly produced from the storage medium, resulting in time loss and image deterioration due to the copying process.

Further, the master is exposed to a laser beam, a latent image,
It is possible to directly form a plate by the development and fixing process, but for that purpose, a laser of argon, helium neon, helium cadmium, YAG, carbon dioxide gas, etc. is required, so that the apparatus becomes large and power consumption is reduced. There are problems such as an increase in the amount and an accompanying increase in cost.

On the other hand, recently, electrophotographic recording apparatuses have become widespread, and as a result, semiconductor lasers or LEDs used for exposure have been improved in performance and price, and have various characteristics. Attention has been focused on the exposure light source as disclosed in Japanese Patent Laid-Open No. 5-72822.

However, the conventional zinc oxide master paper cannot be used because the light source has a long wave length of 600 nm or more and has a low sensitivity.

[0008]

As described above, the zinc oxide master paper currently used as a simple printing plate has a certain degree of simplicity, but it is required to be compatible with the electronic editing apparatus such as a personal computer which is required by the times. I need a joint.

However, for that purpose, it is necessary to have good sensitivity to semiconductor lasers and LEDs that have been used at present, and the current zinc oxide master has a sensitivity problem.

[0010]

In order to solve the above problems, the printing plate material of the present invention is characterized by a combination of a light-sensitive material and a binder, which substitutes a hydrogen atom of a carboxylic acid group contained in the binder, This binder reacts with dampening water having hydrophilicity to make it hydrophilic and has sensitivity to the wavelength of a semiconductor laser or LED.
A single-layer photoreceptor system of a photosensitive material and a binder, in particular, a metal-free phthalocyanine is used as the photosensitive material and a copolymer of a binder having a carboxylic acid group and a system having two vinyl groups, or A copolymer having a carboxylic acid group and a vinyl group having two vinyl groups is further used.

That is, the printing plate material of the present invention uses a metal-free phthalocyanine as a charge generating agent on a conductive support and a copolymer of the following (Chemical formula 7) and (Chemical formula 8) as a binder, or the following. In addition to (Chemical formula 7) and (Chemical formula 8), a single layer photosensitive material using a copolymer with at least one of the following (Chemical formula 9), (Chemical formula 10), (Chemical formula 11) and (Chemical formula 12) It is a printing plate material in which materials are arranged, and a portion other than the toner adhering portion adhered by the electrophotographic process is made hydrophilic to wet water treatment.

[0012]

[Chemical 7]

[0013]

Embedded image

[0014]

[Chemical 9]

[0015]

[Chemical 10]

[0016]

[Chemical 11]

[0017]

[Chemical 12]

Here, R is an alkyl group containing a carbon atom or a hydrogen atom, is a benzene ring, and R'is an alkyl group containing 1 to 4 carbon atoms.

Further, the ratio of the compound of the chemical formula 8 is 8% with respect to the total amount of the binder system other than the compound of the chemical formula 8 above.
The following is preferable.

In such an arrangement, a semiconductor laser or LED can be used as an exposure light source in the electrophotographic process.

As the conductive support, not only a conductive member such as aluminum but also a conductive material such as aluminum vapor-deposited and plated on a plastic sheet, paper, a plastic plate or the like is subjected to a conductive treatment. Things can also be used.

As the charge generating agent, a metal-free X-type phthalocyanine or τ-type metal phthalocyanine as a phthalocyanine pigment can also be used.

Further, as the binder, a copolymer obtained by combining the compounds of (Chemical formula 7) to (Chemical formula 12) is used. Examples of the compound represented by (Chemical formula 7) include acrylic acid, methacrylic acid and the like. Other examples include crotonic acid, itaconic acid, fumaric acid, maleic acid, cinnamic acid, and styrylacetic acid.

Further, as an example of the compound having two vinyl groups represented by the chemical formula (8), for example, divinylbenzene is generally used, but in addition, divinylpyridine, divinyltoluene, divinylnaphthalene, dimethacrylate, divinyl. Examples thereof include those capable of crosslinking such as ketone and styryl acrylic acid.

Further, as the compound having the ester of (formula 9), acrylate or methacrylate of which the terminal alkyl group is methyl, ethyl, propyl, butyl, or larger lauryl, cetyl, dodecyl, etc. Examples thereof include hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl acrylate and methacrylate having a hydroxy group at the terminal.

Further, examples of the compound having one vinyl group of (Chemical Formula 11) or (Chemical Formula 12) include styrene, and one containing one in a linear alkyl group.

[0027]

In the present invention, an electrophotographic process is used,
Offset printing is possible by using a semiconductor laser or LED as an exposure light source and applying a toner to the exposed area to form a printing plate and coating the surface with dampening water to make the non-toner area hydrophilic. It becomes the printing plate material.

Specifically, since the toner-adhered portion is hydrophobic, the printing ink adheres to it, while the non-toner-adhered portion is hydrophilized and water does not adhere to the ink so that the printing does not occur. You can do it.

[0029]

EXAMPLES Examples of the present invention will be described below.

In general, as a method for producing a printing plate material for simple printing, an electrophotographic process is applied to an original plate of a photosensitive material, the surface is first charged by a corona charger, and then,
A required portion is exposed, the toner is attached by utilizing the difference in potential between the exposed portion and the non-exposed portion, and then the toner is heated and fixed.

In this state, there are a toner adhering portion and a toner non-adhering portion, and the normal toner portion exhibits resistance to an organic solvent.

After this, two types of processes can be taken. First, on the other hand, dissolve the toner non-adhesive part with a solvent,
This is a method of forming an offset printing plate using a previously hydrophilized support after dissolution and a toner part configuration having new ink properties.

On the other hand, a printing plate using zinc oxide as a light-sensitive material, to which a fountain solution, which is a solvent having a hydrophilic group, reacts with a solvent that reacts with the toner non-adhesive portion is attached.

The dampening water is water repellent to the toner portion and is not made hydrophilic. As described above, the other method does not have a process of dissolving and removing, and is very simple in terms of equipment.

Therefore, in this embodiment, the other process is used, and as the photosensitive material, phthalocyanine having sensitivity in a long wavelength region such as LED and semiconductor laser is used and mixed with a binder to form a single-layer photosensitive material. Is.

The above-mentioned copolymer is used as a binder, mixed and dispersed with phthalocyanine as a light-sensitive material, coated and dried on a conductive support to obtain a printing plate material.

With such a structure, since the phthalocyanine itself has a large water repellent property on the surface of the printing plate material, this effect is greatly exhibited and a hydrophobic state close to the water repellent property can be effectively realized.

Then, in order to make the surface hydrophilic to dampening water, the hydrogen of the carboxylic acid used in the binder is replaced, for example, the hydrophilicity of X having a hydroxyl group is utilized to form a COOH group. It is a COOX-based product.

(First Embodiment) The first embodiment of the present invention will be described below.

In this example, changes in properties due to the degree of cross-linking due to cross-linking with the compound of Chemical formula 8 were examined.

As a typical example of the compound of Chemical formula 8,
Explain using vinylbenzene. Hereinafter, in order to determine the amount ratio of the compound of (Chemical formula 8), the toner adhesion state and hydrophilicity were examined.

The sample was prepared as follows. Benzoyl peroxide 1 was obtained by changing the amount ratio of divinylbenzene similarly distilled under reduced pressure to commercially available methacrylic acid that was previously distilled under reduced pressure.
% Is heated and polymerized in a closed container at 65 ° C. for 4 hours or more, soluble substances are removed and washed with a 2N sodium hydroxide solution, THF is added and the mixture is stirred well and then filtered with a filter.

Next, the ratio of the metal-free phthalocyanine to the solid content of the binder was set to 1/2 wt, and after stirring for 5 hours with a ball mill, a film was formed on the surface of aluminum vapor-deposited on mylar with a bar coater to a film thickness of 5 ± 1 μm. , This is 120 ℃
The sample was dried for 3 hours.

Using such a sample, the toner adhesion state and hydrophilicity were examined as a test method for determining the optimum amount ratio of divinylbenzene.

The toner adhesion state was examined by appropriately changing the electrophotographic process type plate used in the zinc oxide master.

Toner adhesion was evaluated by drawing a 0.1 mm fine line and visually inspecting with a loupe.

With respect to hydrophilicity, 10% triethanolamine was used as fountain solution to evaluate whether or not hydrophilicity can be retained.

The results are shown in (Table 1) below.

[0049]

[Table 1]

When the amount ratio of divinylbenzene was 8%, the recording fine lines due to toner adhesion were not continuous but were partially cut off and toner was not adhered, and the surface of the photosensitive layer was considerably uneven ( In the table, it is written as Fukichi.).

When the amount ratio of divinylbenzene is 5%, the thickness of the recording thin line is not constant and some thin portions are seen, but this is not a problem in practical use (somewhat in the table). Described as uniform.).

On the other hand, the amount ratio of divinylbenzene is 0.05.
%, It means that a small part of the toner peels off when dampening water is applied to the surface, and although it can withstand the minimum use, if the amount ratio of divinylbenzene is 0.01%. When a dampening water was applied to the surface, a considerable part of the toner was peeled off, and the hydrophilicity was not stable and the toner could not be used.

From the above results, it is preferable that the addition amount of divinylbenzene is 0.01% or more and 5% or less, and the addition amount ratio of the compound represented by the chemical formula 8 is 0.01% or more and 5% or less.
It can be seen that it is suitable if it is less than%.

(Second Embodiment) The second embodiment of the present invention will be described below.

In this example, in addition to the compounds of (Chemical formula 7) and (Chemical formula 8), the toner adhesion and hydrophilicity of the copolymers of the compounds of (Chemical formula 9) to (Chemical formula 11) will be examined. .

Specifically, methacrylic acid is a typical example of the compound of chemical formula 7, divinylbenzene is a typical example of the compound of chemical formula 8, and hydroxymethyl having a hydroxyl group is a typical example of the compound of chemical formula 9. A copolymer of three kinds of methacrylic acid, methacrylic acid as a representative example of the compound of (Chemical formula 7), divinylbenzene as a representative example of the compound of (Chemical formula 8), and ethyl methacrylate as a representative example of the compound of (Chemical formula 10). And a methacrylic acid as a representative example of the compound of (Chemical formula 7), divinylbenzene as a representative example of the compound of (Chemical formula 8) and styrene as a representative example of the compound of (Chemical formula 11). A copolymer consisting of

The polymerization method, sample preparation method and evaluation method in this example were the same as in Example 1, except that divinylbenzene was added at a ratio of 1%, and the results of toner adhesion and hydrophilicity were as follows. Each is shown in (Table 2) to (Table 4).

These materials were obtained by removing the polymerization inhibitor by vacuum distillation. Also, as a polymerization catalyst,
Although benzoyl peroxide was used, other organic peroxides such as acetyl peroxide, lauroyl peroxide, and tertiary butyl perbenzoate, and barium peroxide, sodium peroxide, hydrogen peroxide, etc. in the case of an inorganic catalyst were used. Can be used.

[0059]

[Table 2]

In Table 2, defective toner adhesion indicates a state where the toner adhesion amount is extremely small as a whole and the photosensitive characteristics are deteriorated.

[0061]

[Table 3]

[0062]

[Table 4]

In Table 4, the non-hydrophilic property was in a state of exhibiting water repellency. From the above, it was found that the composition can be sufficiently used even in the composite system under the normal composition conditions in which the amount ratio of divinylbenzene is 1% and the ratios of methacrylic acid and hydroxymethyl methacrylate are almost equal.

[0064]

According to the present invention, with the above construction, the toner-adhered portion can be made to be water-repellent and the toner-non-adhered portion can be made hydrophilic with respect to dampening water.
A printing plate material having sufficient sensitivity to light from a semiconductor laser or the like can be realized.

Claims (3)

[Claims] 1. A metal-free phthalocyanine is used as a charge generating agent on a conductive support and a copolymer of the following (Chemical formula 1) and (Chemical formula 2) is used as a binder, or the following (Chemical formula 1) and (Chemical formula 2). ), A printing plate material further comprising a single-layer photosensitive material using a copolymer with at least one of the following (Chemical Formula 3), (Chemical Formula 4), (Chemical Formula 5) and (Chemical Formula 6). A printing plate material in which portions other than the toner-attached portion adhered by the electrophotographic process are rendered hydrophilic to wet water treatment. Embedded image Embedded image Embedded image [Chemical 4] Embedded image [Chemical 6] Here, R represents an alkyl group containing a carbon atom or a hydrogen atom, ∘ represents a benzene ring, and R ′ represents an alkyl group containing 1-4 carbon atoms. 2. The printing plate material according to claim 1, wherein the ratio of the compound of the chemical formula 2 is 8% or less based on the total amount of the binder system other than the compound of the chemical formula 2. 3. The printing plate material according to claim 1, wherein a semiconductor laser or an LED is used as an exposure light source in the electrophotographic process.