AQUEOUS DEVELOPER FOR FLEXOGRAPHIC PRINTING PLATE AND MANUFACTURING METHOD OF FLEXOGRAPHIC PRINTING PLATE

Abstract

An object of the present invention is to provide an aqueous developer for a flexographic printing plate capable of maintaining good developability and suppressing aggregation of a dispersion in the developer diluted with water after repeated use, and a manufacturing method of a flexographic printing plate using the same. The aqueous developer for a flexographic printing plate according to the present invention is an aqueous developer for a flexographic printing plate, containing a nonionic surfactant represented by Formula (1), and water.

R.sup.1O—(AO).sub.n—H   (1)

Here, in Formula (1),

R.sup.1 represents a linear aliphatic hydrocarbon group having 9 to 30 carbon atoms,

A represents an alkylene group having 2 to 4 carbon atoms, and

n represents an integer of 7 or more, in which in a case where n is an integer of 2 or more, a plurality of A's may be the same or different from each other.

Claims

1. An aqueous developer for a flexographic printing plate, comprising: a nonionic surfactant represented by Formula (1); and water,
R.sup.1O—(AO).sub.n—H   (1) where, in Formula (1), R.sup.1 represents a linear aliphatic hydrocarbon group having 9 to 30 carbon atoms, A represents an alkylene group having 2 to 4 carbon atoms, and n represents an integer of 7 or more, in which in a case where n is an integer of 2 or more, a plurality of A's may be the same or different from each other.

2. The aqueous developer for a flexographic printing plate according to claim 1, wherein n in Formula (1) is an integer of 10 or more.

3. The aqueous developer for a flexographic printing plate according to claim 1, wherein n in Formula (1) is an integer of 15 or more.

4. The aqueous developer for a flexographic printing plate according to claim 1, wherein R.sup.1 in Formula (1) has an ethylenically unsaturated double bond.

5. The aqueous developer for a flexographic printing plate according to claim 1, further comprising: an anionic surfactant represented by Formula (2),
R.sup.2—X   (2) here, in Formula (2), R.sup.2 represents an aliphatic hydrocarbon group having 7 to 15 carbon atoms, and X represents a carboxylic acid group or a salt of the carboxylic acid group, a sulfonic acid group or a salt of the sulfonic acid group, a sulfate group or a salt of the sulfate group, or a phosphoric acid group or a salt of the phosphoric acid group.

6. A manufacturing method of a flexographic printing plate having a non-image area and an image area, the manufacturing method comprising: an exposure step of imagewise exposing a photosensitive layer in a flexographic printing plate precursor having the photosensitive layer; a development step of, after the exposure step, performing development using the aqueous developer for a flexographic printing plate according to claim 1 to form a non-image area and an image area; and a rinse step of, after the development step, performing rinsing with water.

7. The aqueous developer for a flexographic printing plate according to claim 2, wherein n in Formula (1) is an integer of 15 or more.

8. The aqueous developer for a flexographic printing plate according to claim 2, wherein R.sup.1 in Formula (1) has an ethylenically unsaturated double bond.

9. The aqueous developer for a flexographic printing plate according to claim 2, further comprising: an anionic surfactant represented by Formula (2),
R.sup.2—X   (2) here, in Formula (2), R.sup.2 represents an aliphatic hydrocarbon group having 7 to 15 carbon atoms, and X represents a carboxylic acid group or a salt of the carboxylic acid group, a sulfonic acid group or a salt of the sulfonic acid group, a sulfate group or a salt of the sulfate group, or a phosphoric acid group or a salt of the phosphoric acid group.

10. A manufacturing method of a flexographic printing plate having a non-image area and an image area, the manufacturing method comprising: an exposure step of imagewise exposing a photosensitive layer in a flexographic printing plate precursor having the photosensitive layer; a development step of, after the exposure step, performing development using the aqueous developer for a flexographic printing plate according to claim 2 to form a non-image area and an image area; and a rinse step of, after the development step, performing rinsing with water.

11. The aqueous developer for a flexographic printing plate according to claim 3, wherein R.sup.1 in Formula (1) has an ethylenically unsaturated double bond.

12. The aqueous developer for a flexographic printing plate according to claim 3, further comprising: an anionic surfactant represented by Formula (2),
R.sup.2—X   (2) here, in Formula (2), R.sup.2 represents an aliphatic hydrocarbon group having 7 to 15 carbon atoms, and X represents a carboxylic acid group or a salt of the carboxylic acid group, a sulfonic acid group or a salt of the sulfonic acid group, a sulfate group or a salt of the sulfate group, or a phosphoric acid group or a salt of the phosphoric acid group.

13. A manufacturing method of a flexographic printing plate having a non-image area and an image area, the manufacturing method comprising: an exposure step of imagewise exposing a photosensitive layer in a flexographic printing plate precursor having the photosensitive layer; a development step of, after the exposure step, performing development using the aqueous developer for a flexographic printing plate according to claim 3 to form a non-image area and an image area; and a rinse step of, after the development step, performing rinsing with water.

14. The aqueous developer for a flexographic printing plate according to claim 4, further comprising: an anionic surfactant represented by Formula (2),
R.sup.2—X   (2) here, in Formula (2), R.sup.2 represents an aliphatic hydrocarbon group having 7 to 15 carbon atoms, and X represents a carboxylic acid group or a salt of the carboxylic acid group, a sulfonic acid group or a salt of the sulfonic acid group, a sulfate group or a salt of the sulfate group, or a phosphoric acid group or a salt of the phosphoric acid group.

15. A manufacturing method of a flexographic printing plate having a non-image area and an image area, the manufacturing method comprising: an exposure step of imagewise exposing a photosensitive layer in a flexographic printing plate precursor having the photosensitive layer; a development step of, after the exposure step, performing development using the aqueous developer for a flexographic printing plate according to claim 4 to form a non-image area and an image area; and a rinse step of, after the development step, performing rinsing with water.

16. A manufacturing method of a flexographic printing plate having a non-image area and an image area, the manufacturing method comprising: an exposure step of imagewise exposing a photosensitive layer in a flexographic printing plate precursor having the photosensitive layer; a development step of, after the exposure step, performing development using the aqueous developer for a flexographic printing plate according to claim 5 to form a non-image area and an image area; and a rinse step of, after the development step, performing rinsing with water.

Description

EXAMPLES

[0128] Hereinafter, the present invention will be described in more detail with reference to examples. Materials, amounts used, ratios, treatment contents, treatment procedures, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

Synthesis of Nonionic Surfactant CW-1

[0129] Potassium hydroxide was added to octanol so that the concentration was 1% by mass, and the 20 molar equivalents of ethylene oxide was blown into 1 molar equivalent of octanol under the condition of 180±5° C. to obtain polyoxyethylene octyl ether. The number of moles of ethylene oxide to be added was confirmed by measuring the mass increase amount.

Examples 1 to 7 and Comparative Examples 1 to 5

[0130] Each water, alkali agent, nonionic surfactant, and anionic surfactant shown in Table 1 below were formulated to have parts by mass shown in Table 1 below, thereby preparing aqueous developers.

Evaluation

Developability

[0131] A cover film of a flexographic printing plate precursor [FLENEX FW-L2, manufactured by FUJIFILM Corporation] was peeled off, and the flexographic printing plate precursor was exposed with an exposure device in which 15 40 W chemical lamps were arranged for 2 seconds from a substrate side from a distance of 15 cm (back exposure).

[0132] Thereafter, development was performed for 3 minutes with a brush type washing machine (liquid temperature: 50° C.) containing each of the prepared aqueous developers.

[0133] Thereafter, the obtained flexographic printing plate was dried with hot air of 60° C. until the moisture was removed. The thickness of the obtained flexographic printing plate was measured using a constant pressure thickness measuring device, and the change in film thickness per minute (development speed) was calculated from the change in thickness before and after development. The evaluation was performed according to the following standard. The results are shown in Table 1 below. Practically, it is preferable that the evaluation is B or higher.

Evaluation Standard

[0134] A: development speed was 170 μm/min or more.

[0135] B: development speed was 100 μm/min or more and less than 170 μm/min.

[0136] C: development speed was less than 100 μm/min.

Suppression of Aggregation

[0137] A cover film of a flexographic printing plate precursor [FLENEX FW-L2, manufactured by FUJIFILM Corporation] was peeled off, and the flexographic printing plate precursor was exposed with an exposure device in which 15 40 W chemical lamps were arranged for 2 seconds from a substrate side from a distance of 15 cm (back exposure).

[0138] Thereafter, with a brush type washing machine (liquid temperature: 50° C.) containing each of the prepared aqueous developers, development was performed for an optional time so that the solid content of a developing residue (dispersion) was 7.0% by mass. The solid content of the developing residue was obtained by measuring 2.0 g of the aqueous developer used (hereinafter, also abbreviated as a “fatigue solution”), drying at 95° C. for 18 hours, and calculating solid content % in the fatigue solution from the weight change before and after drying.

[0139] Next, 50 cc of the fatigue solution was put into a 1000 cc plastic container containing 450 cc of water in advance, the mixture was stirred and allowed to stand for 12 hours, and aggregates in the liquid was visually observed and evaluated according to the following standard. The results are shown in Table 1 below.

Evaluation Standard

[0140] A: there were no large aggregates which could be visually identified.

[0141] B: slightly large aggregates which could be visually identified were generated.

[0142] C: small amount of large aggregates which could be visually identified was generated.

[0143] D: large amount of large aggregates which could be visually identified was generated.

Stability of Concentrated Solution

[0144] With regard to each aqueous developing concentrated solution obtained by preparing each aqueous developer at a concentration ratio of 10 times, a dissolved state at room temperature (23° C.) was visually observed and evaluated according to the following standard. The results are shown in Table 1 below. In a case where the evaluation is B or more, there is no practical problem.

Evaluation Standard

[0145] A: colorless and transparent

[0146] B: turbidity

[0147] C: two-layer separation

[0148] D: insoluble precipitate

TABLE-US-00001 TABLE 1 Nonionic surfactant R.sup.1 in Formula (1) Water Alkali agent Number Ethylenically Formula % by % by Product name of carbon unsaturated (1) Material mass Material mass and the like Manufacturer atoms double bond A Example 1 Pure 98.9 Sodium 0.1 Emulgen 108 Kao Corporation 12 None Ethylene water carbonate group Example 2 Pure 98.9 Sodium 0.1 Pionin D-1115 TAKEMOTO 12 None Ethylene water carbonate OIL & FAT group Co., Ltd. Example 3 Pure 98.9 Sodium 0.1 Pionin D-1315 TAKEMOTO 16 None Ethylene water carbonate OIL & FAT group Co., Ltd. Example 4 Pure 98.9 Sodium 0.1 Pionin D-1323 TAKEMOTO 16 None Ethylene water carbonate OIL & FAT group Co., Ltd. Example 5 Pure 98.9 Sodium 0.1 Pionin D-1420 TAKEMOTO 18 None Ethylene water carbonate OIL & FAT group Co., Ltd. Example 6 Pure 98.9 Sodium 0.1 Pionin D-1518 TAKEMOTO 18 Having Ethylene water carbonate OIL & FAT group Co., Ltd. Example 7 Pure 97.75 Sodium 0.25 Pionin D-1315 TAKEMOTO 16 None Ethylene water carbonate OIL & FAT group Co., Ltd. Comparative Pure 98.9 Sodium 0.1 Pionin D-1004 TAKEMOTO 8 None Ethylene Example 1 water carbonate OIL & FAT group Co., Ltd. Comparative Pure 98.9 Sodium 0.1 Pionin D-1007 TAKEMOTO 8 None Ethylene Example 2 water carbonate OIL & FAT group Co., Ltd. Comparative Pure 98.9 Sodium 0.1 CW-1 Synthetic 8 None Ethylene Example 3 water carbonate product group Comparative Pure 98.9 Sodium 0.1 Emulgen 104P Kao Corporation 12 None Ethylene Example 4 water carbonate group Comparative Pure 98.9 Sodium 0.1 Polyoxyethylene FUJIFILM 18 None Ethylene Example 5 water carbonate (4) stearyl ether Wake Chemical group Corporation Nonionic surfactant Formula Anionic surfactant Suppression Stability of (1) % by % by of concentrated B HLB mass Material mass Developability aggregation solution Example 1 8 12.1 1 None B A B Example 2 15 15.6 1 None B B A Example 3 15 14.6 1 None B A B Example 4 23 15.7 1 None B C B Example 5 20 15.3 1 None B B B Example 6 18 11.4 1 None B A A Example 7 15 14.6 1 Sodium 1 A A A laurate Comparative 4 11.6 1 None B D C Example 1 Comparative 8 14.6 1 None B D C Example 2 Comparative 20 17.4 1 None B D B Example 3 Comparative 4 9.6 1 None B D D Example 4 Comparative 4 7.9 1 None B D D Example 5 The following components were used as the components shown in Table 1 above. Sodium carbonate: reagent manufactured by FUJIFILM Wako Chemical Corporation Emulgen 108: polyoxyethylene lauryl ether (HLB: 12.0, manufactured by Kao Corporation) Pionin D-1115: polyoxyethylene lauryl ether (manufactured by TAKEMOTO OIL & FAT Co., Ltd.) Pionin D-1315: polyoxyethylene cetyl ether (manufactured by TAKEMOTO OIL & FAT Co., Ltd.) Pionin D-1323: polyoxyethylene cetyl ether (manufactured by TAKEMOTO OIL & FAT Co., Ltd.) Pionin D-1420: polyoxyethylene stearyl ether (manufactured by TAKEMOTO OIL & FAT Co., Ltd.) Pionin D-1518: polyoxyethylene oleyl ether (manufactured by TAKEMOTO OIL & FAT Co., Ltd.) Pionin D-1004: polyoxyethylene octyl ether (manufactured by TAKEMOTO OIL & FAT Co., Ltd.) Pionin D-1007: polyoxyethylene octyl ether (manufactured by TAKEMOTO OIL & FAT Co., Ltd.) CW-1: synthetic product described above Emulgen 104P: polyoxyethylene lauryl ether (HLB: 9.7, manufactured by Kao Corporation) Polyoxyethylene (4) stearyl ether: reagent manufactured by FUJIFILM Wako Chemical Corporation Sodium laurate: reagent manufactured by FUJIFILM Wako Chemical Corporation

[0149] As shown in Table 1, it was found that, in a case where R.sup.1 in Formula (1) described above was an aliphatic hydrocarbon group having 8 carbon atoms, the aggregation of developing residue could not be suppressed regardless of the number of n in Formula (1) described above (Comparative Examples 1 to 3).

[0150] In addition, even in a case where R.sup.1 in Formula (1) described above was a linear aliphatic hydrocarbon group having 9 to 30 carbon atoms, it was found that, in a case where n in Formula (1) described above was an integer of less than 7, the aggregation of developing residue could not be suppressed, and the stability of the concentrated solution was deteriorated (Comparative Examples 4 and 5).

[0151] On the other hand, it was found that, in a case where the specific surfactant was formulated, good developability could be maintained and the aggregation of the developing residue could be suppressed (Examples 1 to 7).

[0152] In particular, from the comparison between Example 3 and Example 7, it was found that, in a case where the anionic surfactant represented by Formula (2) described above was formulated, the developability was improved, and the stability of the concentrated solution obtained by concentrating the aqueous developer was improved.

[0153] In addition, from the comparison between Example 5 and Example 6, it was found that, in a case where R.sup.1 in Formula (1) described above had an ethylenically unsaturated double bond (carbon-carbon double bond), the aggregation of developing residue in the fatigue solution could be further suppressed.