JP2692716B2 - Flexographic printing plate developer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention is a novel developer for flexographic printing plates. More specifically, it is capable of forming a relief having particularly excellent reproducibility, has high safety, and is preferable in terms of work hygiene and environment. The present invention relates to a developing solution used in making a flexographic printing plate.

[0002]

2. Description of the Related Art As a photosensitive resin composition for a flexographic printing plate, a photosensitive resin composition comprising a thermoplastic elastomer, a photopolymerizable unsaturated monomer and a photopolymerization initiator is well known (for example, JP-B-51). -43374, Japanese Patent Publication No. 59-2
2219 publication).

In the case of producing a flexographic printing plate using these photosensitive resin compositions, after irradiating an actinic ray through a mask having a required pattern, the unexposed part of the actinic ray is dissolved or swollen by a developing solution. Although it is necessary to remove the halogenated hydrocarbons such as chloroform, trichloroethane, trichloroethylene, tetrachloroethylene and the like as a developing solution used for such a photosensitive resin composition, a mixture of these and alcohols. Are used.

However, since these developers swell not only in the unexposed areas but also in the exposed areas, a pattern having excellent reproducibility cannot be obtained, and halogenated hydrocarbons are safe in terms of hygiene and environment. It is not preferable in terms of sex.

[0005]

The present invention overcomes the drawbacks of the conventional developing solutions for flexographic printing plates,
The purpose of the present invention is to provide a developing solution for flexographic printing plates, which has excellent reproducibility, high safety, and has no problems in working hygiene and environment.

[0006]

The inventors of the present invention have conducted various studies on a developing solution for flexographic printing plates, and as a result, a developing solution containing a specific organic solvent, a surfactant and water is faithful to the original plate. Based on this finding, it was found that there is no problem in terms of workability and environmental safety, and the present invention has been completed.

That is, the present invention is a developer for use in making a flexographic printing plate using a photosensitive resin composition comprising a thermoplastic elastomer, a photopolymerizable unsaturated monomer and a photopolymerization initiator. And has a solubility in water of 2
It comprises 10% by weight or less of alkylated benzene at 0 ° C., a surfactant having an action of dispersing or dissolving the alkylated benzene in water, and water, and the content of alkylated benzene is 10 to 70% by weight based on the total amount of the developing solution. %, And the content of the surfactant is 0.1% based on the weight of the alkylated benzene.
The present invention provides a developing solution for flexographic printing plates, characterized in that it is in the range of 1 to 20% by weight and the alkylated benzene is homogeneously dispersed or dissolved in water.

The photosensitive resin composition which can be developed with the developing solution of the present invention comprises a thermoplastic elastomer, a photopolymerizable unsaturated monomer and a photopolymerization initiator. Here, the thermoplastic elastomer is a polymer material having the same properties as a vulcanized rubber at room temperature and having the same properties as an ordinary thermoplastic resin at a high temperature, such as styrene-based, olefin-based, polyester-based, polyurethane. System, polyisoprene system,
A wide variety of 1,2-polybutadiene type, vinyl chloride type, polyamide type and the like are known. Among these thermoplastic elastomers, particularly preferable one is a styrene-based thermoplastic elastomer, specifically, styrene / butadiene / styrene block copolymer, styrene /
Isoprene / styrene block copolymers and hydrogenated products thereof. These thermoplastic elastomers are contained in the photosensitive resin composition in an amount of usually 30 to 95% by weight, preferably 5% by weight.
It is compounded in the range of 0 to 85% by weight. This amount is 30
If it is less than wt%, a photosensitive resin composition excellent in rubber elasticity cannot be obtained, and if it exceeds 95 wt%, a pattern having excellent reproducibility becomes difficult to be formed.

Regarding the photopolymerizable unsaturated monomer,
There is no particular limitation as long as it is compatible with or mixable with the thermoplastic elastomer. Specific examples thereof include photopolymerizable unsaturated monomers having at least one vinyl group, and examples thereof include those having 2 carbon atoms.
-10, especially C2-C6 aliphatic and cycloaliphatic diols, such as ethylene glycol, triethylene glycol, hexanediol, cyclohexanediol, and C3-C5 ethylenically unsaturated carboxylic acids, such as acrylic acid and Examples thereof include diesters and triols derived from methacrylic acid and the like, triesters derived from the unsaturated carboxylic acids, and vinyl esters of polycarboxylic acids. These may be used alone or in combination of two or more. The blending amount of these photopolymerizable unsaturated monomers is usually selected in the range of 3 to 80 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of the thermoplastic elastomer. If this amount is less than 3 parts by weight, a pattern with excellent reproducibility cannot be obtained.
If it exceeds the weight part, good rubber elasticity cannot be obtained.

Further, the photopolymerization initiator is not particularly limited, and any known photopolymerization initiator conventionally used for this type of photosensitive resin can be selected and used. Especially benzoin type, benzophenone type,
Anthraquinone type is preferable. These photopolymerization initiators may be used alone or in combination of two or more.
The blending amount of these photopolymerization initiators is usually selected in the range of 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the thermoplastic elastomer. If this amount is 0.
If it is less than 1 part by weight, practical sensitivity cannot be obtained,
If it exceeds 5 parts by weight, a good pattern cannot be obtained.

The photosensitive resin composition may contain, if desired, a cresol-based, phenol-based, hydroquinone-based thermal polymerization inhibitor, a synthetic resin, a pigment, a dye, a plasticizer, an antioxidant, a photodegradation inhibitor, or the like. Can be blended in an appropriate amount.

The photosensitive resin composition which can be developed with the developing solution of the present invention is used in accordance with a known method, for example, the above-mentioned thermoplastic elastomer, photopolymerizable unsaturated monomer, photopolymerization initiator and if desired. By dissolving the various added components in an organic solvent, and then forming the film or plate as it is, by removing the solvent, or after mixing with a roll mixer, by forming into a film or plate by hot pressing, A photosensitive resin layer for producing flexographic relief can be formed. The photosensitive resin layer thus obtained is pressure-bonded to a polyester plate, a steel plate, an aluminum plate or the like, and after selectively irradiating an actinic ray through a mask,
By washing off the unirradiated portion with a developer, a relief printing plate for flexographic printing having rubber elasticity can be obtained.

The developer of the present invention is used for preparing a relief printing plate for flexographic printing using the above-mentioned photosensitive resin composition, and has a solubility in water of 1 at 20 ° C.
It is capable of dissolving or swelling the unexposed portion of the photosensitive resin composition, which comprises 0% by weight or less of alkylated benzene, a surfactant and water.

Examples of the alkylated benzene include toluene, xylene, trimethylbenzene, methylethylbenzene, tetramethylbenzene, isopropylmethylbenzene, ethylbenzene and diethylbenzene. These may be used alone or in combination of two or more.

It is necessary that these alkylated benzenes are blended in the range of 10 to 70% by weight based on the total amount of the developing solution. If this amount is less than 10% by weight, the developing time becomes long, and development fatigue becomes fast.
If it exceeds 5% by weight, the amount of alkylated benzene increases and the working environment is deteriorated.

The surfactant used in the developer of the present invention is not particularly limited as long as it has a function of dissolving or dispersing alkylated benzene in water. For example, any of anionic, cationic, and nonionic types can be used. Specifically, higher alcohol sulfate sodium salt, aliphatic quaternary ammonium salt, aliphatic amine salt, polyoxyethylene alkyl ether, polyoxyethylene glycerin fatty acid ester, polyethylene glycol fatty acid ester and the like are used.

These surfactants may be used alone or in combination of two or more kinds. Further, the blending amount is 0.1 to 2 with respect to the alkylated benzene.
It is selected in the range of 0% by weight. If this amount is less than 0.1% by weight, the alkylated benzene will not be uniformly dispersed or dissolved in water, and if it exceeds 20% by weight, no improvement in properties will be observed for that amount, which is rather economically disadvantageous. Become.

[0018]

INDUSTRIAL APPLICABILITY The developer for flexographic printing plates of the present invention is capable of forming a relief with excellent reproducibility in the production of flexographic printing plates, and uses an aqueous solution containing a specific amount of alkylated benzene. Compared with conventional developers, it does not deteriorate the working environment and is safer.
It also has the effect of being favorable in terms of hygiene.

[0019]

Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the present invention.

Example 1 TRKX65S which is a thermoplastic elastomer composed of styrene / butadiene / styrene block copolymer in 200 parts by weight of methyl ethyl ketone (manufactured by Shell Chemical Co., Ltd., weight average molecular weight 140,000, styrene unit content 28% by weight).
100 parts by weight, liquid polybutadiene NISSO-
PBB-1000 (Nippon Soda Co., Ltd., weight average molecular weight 1)
050, 1,2-vinyl 85% by weight or more) 60 parts by weight,
6 parts by weight of trimethylolpropane triacrylate, 2 parts by weight of benzyl dimethyl ketal and 2,6-di-te
0.012 parts by weight of rt-butyl-p-cresol was added and dissolved while stirring in a flask under reflux for about 2 hours to obtain a photopolymerizable composition. This was provided with an adhesive layer 1
It was coated on a PET film support having a thickness of 00 μm so that the film thickness after drying would be 2.74 mm, and then at 12 ° C. at 12 ° C.
Dried for hours.

Next, the chemical lamp FL-40BL
(Toshiba Co., Ltd.), the whole surface was irradiated with an actinic ray from the support side for 2 minutes, a negative film was brought into close contact with the photosensitive layer under reduced pressure, and the actinic ray was selectively irradiated with the chemical lamp for 15 minutes.

Next, a developing solution containing 10 kg of toluene, 2 kg of sodium lauryl sulfate (20% by weight based on toluene) and 10 kg of water, and an eluator Cyrel Proc.
Using an essor (manufactured by DuPont), development treatment was performed at 40 ° C. for 10 minutes to dissolve and remove the unirradiated portion of the photosensitive layer, followed by drying at 50 ° C. for 30 minutes and total irradiation with the chemical lamp for 15 minutes. By doing so, a flexographic printing plate was obtained.

The flexographic printing plate thus obtained was observed, and the reproducibility of highlights at 65 lines / inch, the reproducibility of the minimum independent line width, and the depth of the 0.5 mm blank width portion were examined. Table 1 shows the results. Also, for comparison, 90 kg of 1,1,1-trichloroethane and 10 kg of n-butyl alcohol
A flexographic printing plate was obtained by the same treatment as described above using a developing solution consisting of, and the same observation was carried out. Table 1 also shows the results.

[0024]

[Table 1] Note 1) Represents the limit value at which the highlight of 65 lines / inch is reproduced 2) Represents the minimum reproducible independent line width 3) Represents the depth after plate making of the 0.5 mm open width part

Example 2 As a developer, 8 kg of SWAZOL 150 (a mixture of alkyl-substituted aromatic hydrocarbons such as trimethylbenzene, tetramethylbenzene, isopropylmethylbenzene and diethylbenzene, manufactured by Maruzen Petrochemical Co., Ltd.), Adecatol Np650 (nonionic) Surfactant, manufactured by Asahi Denka Co., Ltd.)
Example 1 except that a developer consisting of 0.2 kg (2.5% by weight with respect to 150 Swasol) and 12 kg of water was used.
A flexographic printing plate was obtained in the same manner as in. As a result of observing this flexographic printing plate, the highlight line reproducibility of 65 lines / inch is 2%, the minimum independent line width reproducibility is 200 μm, 0.5 m.
The depth of the m white width portion was 160 μm.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-63-271256 (JP, A) JP-A-63-85542 (JP, A) JP-A-62-160446 (JP, A) JP-A-2- 7056 (JP, A) JP-A-2-267557 (JP, A)

Claims (1)

(57) [Claims] 1. A developer for use in making a flexographic printing plate using a photosensitive resin composition comprising a thermoplastic elastomer, a photopolymerizable unsaturated monomer and a photopolymerization initiator, It is composed of an alkylated benzene having a solubility in water of 10% by weight or less at 20 ° C., a surfactant having a function of dispersing or dissolving the alkylated benzene in water, and water, and the content of the alkylated benzene is based on the total amount of the developing solution. 10 to 70% by weight, the content of the surfactant is in the range of 0.1 to 20% by weight based on the weight of the alkylated benzene, and the alkylated benzene is homogeneously dispersed or dissolved in water. A developer for flexographic printing plates, which is characterized by: