JPH06242612A - Exposing method for photopolymerizable composition - Google Patents

Abstract

PURPOSE:To provide the photopolymerizable compsn. for a printing plate having high sensitivity and high printing resistance by irradiating the compsn. with active light while applying a magnetic field thereto at the time of recording images by imagewise-irradiating the compsn. with UV light and/or visible light at ordinary temp CONSTITUTION:This solid phase photopolymerizable compsn. contains a photopolymn. initiator, a multifunctional polymerizable monomer and matrix resin and is irradiated with the active light while the magnetic field is applied thereto at the time of recording the images by imagewise-irradiating the photopolymerizable compsn. with the UV light and/or visible light at ordinary temp. The initiation of a photopolymn. reaction is accelerated and the photosensitivity is increased by this exposing method. The way of applying the magnetic field to the compsn. at the time of the exposing more specifically includes a permanent magnet, electromagnet, etc., as the method for application of the magnetic field. The application is executed in a 10<-2> to 10<3> gauss range of magnetic field intensity. A device for exposing the images by an optical fiber, etc., is preferably used as the image exposing method by the UV light and/or visible light. The temp. at the time of the exposing may be ordinary temp. and room temp. range of 10 to 35 deg. is sufficient for the purpose.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of exposing a photopolymerizable composition, and more particularly, to a photopolymerizable composition capable of improving photosensitivity and printing durability in printing plates such as letterpress, planographic printing and gravure printing. The present invention relates to a method of exposing a composition.

[0002]

2. Description of the Related Art Conventionally, for the technique of increasing the degree of polymerization and the rate of polymerization by exposing a photopolymerizable composition to active light while applying a magnetic field, for example, the effect of a magnetic field in low temperature solid state polymerization of acrylonitrile or Regarding the effect of magnetic field on the radiation solid-state polymerization of acetaldehyde, the usefulness of increasing the degree of polymerization by γ-ray irradiation is described in, for example, Industrial Chemistry Journal 73.
Volume 6 (1970) 1215-1220 and Vol. 73, No. 4 (1970) 175-178
Have been reported to.

Further, regarding the increase of the polymerization rate due to the magnetic field effect on the emulsion solution photopolymerization of styrene and its usefulness, for example, J. Am. Chem. Soc. 1983, 105, 1572-1577.

However, in these prior arts, the magnetic field effect when performing image recording by ultraviolet light and / or visible light at room temperature on a solid-phase photopolymerization composition containing a photopolymerization initiator and a polyfunctional polymerizable monomer Is not mentioned at all, nor is there any description suggesting it. It has been desired that the exposure light source is not radiation such as γ-rays, but is capable of image exposure with safe and easy ultraviolet light and / or visible light, and has high sensitivity.

[0005]

SUMMARY OF THE INVENTION Accordingly, the object of the present invention is to eliminate the above-mentioned conventional drawbacks, to increase the photosensitivity and to improve the printing durability of the photopolymerizable composition, and a method for exposing the same. It is to provide a printing plate having high sensitivity and high printing durability.

[0006]

The above problems have been solved by the present invention described below.

That is, a solid phase photopolymerizable composition containing a photopolymerization initiator, a polyfunctional polymerizable monomer and a matrix resin is imagewise irradiated with ultraviolet light and / or visible light at room temperature to record an image. This is achieved by a method for exposing a photopolymerizable composition, which comprises irradiating the photopolymerizable composition with the active light while applying a magnetic field.

The present invention will be described in detail below.

The photopolymerizable composition referred to in the present invention preferably comprises the following components.

(A) Vinyl monomer having at least two terminal vinyl groups (b) Photopolymerization initiator (c) Matrix resin Monomer having at least two terminal vinyl groups of the above component (a) As for the body, Japanese Patent Publications No. 35-5093 and No. 35-1471
No. 9, the same as those described in each publication such as 44-28727 can be used, for example, acrylic acid or methacrylic acid ester of polyol, that is, diethylene glycol-di- (meth)
Acrylate, triethylene glycol-di- (meth) acrylate, pentaerythritol-tri- (meth) acrylate, trimethylolpropane (meth) acrylate, etc.
Or methylenebis (meth) acrylamide, ethylenebis
Unsaturated monomers containing bis (meth) acrylamides such as (meth) acrylamide or urethane groups, for example di-
Examples include reaction products of diol mono (meth) acrylates such as-(2'-methacryloxyethyl) -2,4-tolylene-diurethane and di- (2-acryloxyethyl) trimethylenediurethane with diisocyanates. .

Examples of the photopolymerization initiator of the above component (b) include, for example, J. Kosar, "Light Sensitive Systems", No. 5,
There are carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, and photoreducible dyes as described in Chapter. Specific examples include those disclosed in British Patent 1,459,563.

As the matrix resin of the component (c), various known polymers can be used. For example, polyester resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, vinyl chloride resin, polyamide resin,
Used as a mixture with polyvinyl butyral resin, epoxy resin, acrylate copolymer, vinyl acetate copolymer, phenoxy resin, polyurethane resin, polycarbonate resin, polyacrylonitrile butadiene, polyvinyl acetate, etc. It is preferably used by mixing with an oily polymer compound.

Examples of such lipophilic polymer compounds are:
For example, a copolymer with a monomer having an aliphatic hydroxyl group in its side chain, for example, 2-hydroxyethyl acrylate or another monomer copolymerizable with 2-hydroxyethyl methacrylate can be mentioned. In addition to these, polyvinyl butyral resin, polyurethane resin, polyamide resin, epoxy resin, novolac resin, natural resin and the like may be used if necessary.

The above-mentioned components (a), (b) and (c) according to the present invention
When used, (a) is preferably contained in the photopolymerizable composition in a proportion of 20 to 80% by weight, (b) in a proportion of 0.1 to 20% by weight, and (c) in a proportion of 20 to 80% by weight. . Further, these photopolymerizable compositions may contain a thermal polymerization inhibitor, a plasticizer, a dye, a pigment and the like.

Examples of the solvent used when applying the composition include methyl cellosolve, ethyl cellosolve, ethylene dichloride, cyclohexanone, methyl ethyl ketone, 2-methoxyethyl acetate, monochlorobenzene, toluene, ethyl acetate, tetrahydrofuran and the like. You may use these solvents individually or in combination of 2 or more types.

The matrix resin of the photopolymerizable composition of the present invention preferably contains a microgel.

The microgel used in the present invention has a particle size of 0.005 to 1.0 μm, preferably 0.01 to 0.5 μm.
The inside of the particles is a polymer having a crosslinked structure, and refers to fine particles of a polymer that is insoluble in a solvent and can be dispersed in water or an organic solvent.

The microgel particularly preferably used in the present invention is a cationic latex polymer containing a quaternary nitrogen atom or a quaternary phosphorus atom, for example, Japanese Patent Publication No. 2-47.
The compounds described in Col. 738, column 3, line 33 to column 14, line 31 can be mentioned. The addition amount of these microgels is used in the range of 20 to 80% by weight in the photosensitive composition.

In the present invention, when the above-mentioned photopolymerizable composition is imagewise exposed to ultraviolet light and / or visible light, it is expected that the initiation of the photopolymerization reaction will be enhanced and the sensitivity will be increased by applying a magnetic field. That was not possible.

In the present invention, as a method of applying a magnetic field at the time of exposure, specifically, there are a permanent magnet, an electromagnet, etc. as a magnetic field applying method, and a magnetic field strength of 10 ^-2 to 10 ³
It is preferably performed in the Gauss range.

The image exposure method using ultraviolet light and / or visible light in the present invention can be carried out by an ordinary apparatus, but it is preferable to use an apparatus for image exposure with an optical fiber or the like. The temperature at the time of exposure may be room temperature, for example, in the range of 10 ° C to 35 ° C at room temperature.

[0022]

EXAMPLES The present invention will be described in more detail below with reference to examples.

Example 1 and Comparative Example 1 Two aluminum plates were degreased with a 10% aqueous sodium hydroxide solution, and this was degreased in a 1.8% hydrochloric acid bath at 25 ° C. and 30 / dm ² .
Electrolytic etching is performed under a current density condition of 30 seconds, followed by washing with water and sealing treatment in a 30% sulfuric acid bath at 30 ° C. and 6.5 A / dm ² for 30 seconds.
It was washed with water and dried to obtain an aluminum support for a lithographic printing plate.

Photosensitive solutions as shown in Table 1 were applied to the aluminum plate so that the coating film weight after drying was 20 mg / dm ² to prepare photosensitive lithographic printing plate samples Nos. 1 and 4. .

Negative film Kodak step tablet No. 2 was adhered to each of the obtained samples and 2 KW was applied at room temperature.
After exposing with a metal halide lamp for 30 seconds, the unexposed portion was removed by rubbing with a sponge for 1 minute in water at 25 ° C. to obtain a printing plate having a clear image.

However, among the lithographic printing plates, sample N of the present invention
A magnetic field of 1.1 × 10 ³ Gauss was applied to the o.1 during the exposure.

Example 2 and Comparative Example 2 Sample Nos. 2 and 5 were prepared in the same manner as in Example 1 except that the photosensitive solutions shown in Table 1 were used.

Example 3 and Comparative Example 3 Samples Nos. 3 and 6 were prepared in the same manner as in Example 1 except that the photosensitive solutions shown in Table 1 were used and a 3% aqueous solution of sodium metasilicate was used as the developing solution. Created.

Table 1 shows the results of testing the obtained samples for the presence or absence of a magnetic field.

The composition of the photosensitive solution used for each sample is shown below.

Example 1 Comparative Example 1

[0032]

[Chemical 1]

Trimethylolpropane triacrylate 10 g Diethylthioxanthone 1 g Isoamyl dimethylaminobenzoate 1 g Methylcellosolve 100 g Example 2 Comparative Example 2

[0034]

[Chemical 2]

Trimethylolpropane triacrylate 10 g Diisopropylthioxanthone 1 g Isoamyl dimethylaminobenzoate 1 g Methylcellosolve 100 g Example 3 Comparative Example 3

[0036]

[Chemical 3]

Trimethylolpropane triacrylate 10 g Diisopropylthioxanthone 1 g Isoamyl dimethylaminobenzoate 1 g Methyl cellosolve 100 g

[0038]

[Table 1]

As is apparent from the table, it is understood that excellent photosensitivity and printing durability can be obtained with the photopolymerizable composition according to the present invention and by exposing to active light while applying a magnetic field.

[0040]

Industrial Applicability According to the present invention, which can easily perform image exposure with ultraviolet light and / or visible light while applying a magnetic field, a photopolymerizable composition for a printing plate having high sensitivity and high printing durability can be obtained.

Claims (1)

[Claims] 1. A solid-phase photopolymerizable composition containing a photopolymerization initiator, a polyfunctional polymerizable monomer, and a matrix resin,
A photopolymerizable composition characterized by irradiating the active light while applying a magnetic field to the photopolymerizable composition when image recording is performed by irradiating ultraviolet light and / or visible light imagewise at room temperature. Exposure method.