JP2008126574A - Correction fluid for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing plate image eliminating fluid (correction fluid) which can eliminate the total surface of a printing plate image section for a lithography such as a PS plate using an aluminum as a supporting body, or a thermal CTP plate by containing no hydrogen fluoride or a fluorine compound as an effective component. <P>SOLUTION: This printing plate image eliminating fluid is used for lithographic printing. The printing plate image eliminating fluid contains a kind or more being selected from a group of N-alkyl pyrolidones (γ-butyrolactam), the γ-butyrolactone, and a dehydrated closed ring type saturated complex five-membered ring compound of a tetrahydrofuran, and a kind or more being selected from a group of a monoalkyl ether of glycols (polyoxy alkylene glycol included), and a kind or more of phosphoric acids. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a correction liquid for a lithographic printing plate, and particularly to an invention suitable for erasing the entire plate image portion of a lithographic printing plate such as a PS plate or a thermal CTP plate using aluminum as a support by dipping or the like. Related.

  As a correction liquid (erasing liquid) for printing plate images such as PS plates and thermal CTP plates, etc., in which the surface of aluminum processed to be hydrophilic is a non-image area, consisting of hydrogen fluoride or a fluorine compound and an organic solvent Was the mainstream (see Patent Documents 1, 3, and 4). Hydrogen fluoride or a fluorine compound is designated as an external poison for medicine by the Poisonous and Deleterious Substances Control Law. These correction liquids are scheduled to erase a part of the printing plate image and are generally used with pen-type correction instruments.

  On the other hand, the enforcement of the Personal Information Protection Act of April 1, 2005 requires that all personal information in the printing plate image be deleted, and there is a need to be able to delete the entire printing plate image. is there.

  As a method for erasing the entire printing plate, a method of immersing the entire printing plate in an erasing solution can be considered.

  However, it is necessary to perform the work of immersing and pulling up in the erasing solution containing the above-mentioned pharmaceutical poisonous substance in an open immersion tank. Unlike the above-mentioned closed pen-type correction device, the work safety (work environment) Above) is not desirable.

As a correction liquid (erasing liquid) that does not contain hydrogen fluoride or a fluorine compound, Patent Document 2 proposes a “lithographic printing plate correction agent (correction liquid) containing γ-butyrolactone”. This document does not affect the patentability of the present invention.
Japanese Examined Patent Publication No. 46-16047 (Page 3, Examples 1, 3, 4, 6 etc.) Japanese Patent Publication No. 51-33442 (Claims etc.) Japanese Patent Laid-Open No. 62-27190 (Claims etc.) JP-A-8-324150 (Claims etc.)

  The object of the present invention is to use hydrogen fluoride or fluorine compounds that are designated as pharmaceutical external poisons by the Poisonous and Deleterious Substances Control Law, and further substances that are designated by the Chemical Substance Emission Control Management Promotion Law (PRTR Law) When erasing the entire printing plate image part (the whole printing plate) of the printing plate that does not contain the surface of the plate, such as PS plate and thermal CTP plate, etc., with the surface of the aluminum surface processed to be hydrophilic, as a non-image part. An object of the present invention is to provide a correction liquid for a lithographic printing plate that can easily ensure the safety of the surface.

  As a result of diligent and development efforts to solve the above problems, the present inventors have (A) N-alkylpyrrolidones, γ-lactones or tetrahydrofuran (all of which are dehydrated ring-closed saturated heterocyclic five-membered compounds) ), (B) glycol ethers, and (C) phosphoric acids, the plate can be completely erased not only in the acidic region but also in the basic region by immersing the plate in the composition solution. And came up with a correction liquid for a lithographic printing plate having the following constitution.

  A lithographic printing plate correction solution comprising the following components (A), (B) and (C) as essential components in an aqueous dispersion medium.

(A) component:
1) N-alkylpyrrolidones (γ-lactams) represented by the following general formula (I):
Formula (I)

（但し、Ｒ¹：水素、炭素数１〜１２のアルキル基、炭素数４〜８のシクロアルキル基又は炭素数１〜４のヒドロキシアルキル基）
２）下記一般式（II）で示されるγ−ラクトン類、及び
一般式（II）

(However, R ^1: hydrogen, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group or a hydroxyalkyl group having 1 to 4 carbon atoms having 4 to 8 carbon atoms)
2) γ-lactones represented by the following general formula (II), and general formula (II)

（但し、Ｒ²：水素又は炭素数１〜１２のアルキル基）
３）テトラヒドロフラン
の脱水閉環型の飽和複素五員環化合物の群から選択される１種又は２種以上。

(Where R ^{2 is} hydrogen or an alkyl group having 1 to 12 carbon atoms)
3) One type or two or more types selected from the group of dehydrated ring-closed saturated hetero five-membered ring compounds of tetrahydrofuran.

(B) component:
One or more selected from the group of glycol ethers represented by the following general formula (III).

General formula (III)
R ³ —O (C _n H _2n O) _a —H
(However, R ^{3 is} an alkyl group having 1 to 10 carbon atoms, n: 2, 3 or 4, a: 1 ≦ a ≦ 30.)
Component (C) One or more of phosphoric acids (including phosphoric acid, polyphosphoric acid, organic phosphoric acid and salts thereof).

In the correction fluid having the above configuration, R ¹ in the general formula (I) is an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group, or a hydroxyethyl group, R ² in the general formula (II) is hydrogen, R ³ in the general formula (III): an alkyl group having 2 to 6 carbon atoms, n = 2 or 3, a: 1 or 2 is excellent in the immersion erasing effect.

  The composition of each of the above components includes each component in a composition of (B) component: 10 to 80 parts by mass and (C) component: 10 to 40 parts by mass with respect to (A) component: 100 parts by mass. In addition, with respect to the component (A): 100 parts by mass, the component (B): 20-60 parts by mass, and the component (C): 15-30 parts by mass. Is preferred.

  Hereinafter, the present invention will be described in detail. In the following description, “%” indicating the content means “mass%” unless otherwise specified. Further, “parts” indicating the composition means “parts by mass” unless otherwise specified.

  Here, the case of using as an erasing liquid for erasing the entire plate image portion of a lithographic printing plate will be mainly described as an example, but the correction liquid of the present invention uses a pen-type correction tool for the printing plate image portion. It can also be applied to partial correction (erasing).

  The correction liquid for lithographic printing plate of the present invention (printing plate image part erasing liquid) is (A) component: N-alkylpyrrolidones, γ-lactones or tetrahydrofuran (a group of dehydrated ring-closing saturated saturated five-membered ring compounds), (B) Component: Glycol ethers, (C) Component: Phosphoric acids are essential components (active components).

  Here, the component (A) and the component (B) have the effect of cooperating (synergizing) and dissolving the image portion forming resin of the plate material. In addition, the component (C) has an effect of making the image portion after dissolution hydrophilic to enable complete erasure.

Component (A) (dehydrated ring-closing saturated saturated five-membered ring compound):
1) The N-alkylpyrrolidone (γ-lactam) is represented by the following general formula (I).

    Formula (I)

（但し、Ｒ¹：水素、炭素数１〜１２のアルキル基、炭素数４〜８のシクロアルキル基又は炭素数１〜４のヒドロキシアルキル基）
具体的には、Ｎ−メチルピロリドン、Ｎ−エチルピロリドン、Ｎ−プロピルピロリドン、Ｎ−オクチルピロリドン、Ｎ−ドデシルピロリドン、Ｎ−シクロヘキシル−２−ピロリドン、Ｎ−２−ヒドロキシエチル−２−ピロリドン等を好適に使用できる。

(However, R ^1: hydrogen, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group or a hydroxyalkyl group having 1 to 4 carbon atoms having 4 to 8 carbon atoms)
Specifically, N-methylpyrrolidone, N-ethylpyrrolidone, N-propylpyrrolidone, N-octylpyrrolidone, N-dodecylpyrrolidone, N-cyclohexyl-2-pyrrolidone, N-2-hydroxyethyl-2-pyrrolidone, etc. It can be used suitably.

  2) The above-mentioned γ-lactones are those represented by the following general formula (II).

    Formula (II)

（但し、Ｒ²：水素又は炭素数１〜１２のアルキル基）
具体的には、γ−ブチロラクトン（Ｒ²＝Ｈ）、γ−バレロラクトン（Ｒ²＝ＣＨ₃）、γ−カプロラクトン（Ｒ²＝Ｃ₂Ｈ₅）等を好適に使用できる。

(Where R ^{2 is} hydrogen or an alkyl group having 1 to 12 carbon atoms)
Specifically, γ-butyrolactone (R ² = H), γ-valerolactone (R ² = CH ₃ ), γ-caprolactone (R ² = C ₂ H ₅ ) and the like can be suitably used.

  3) The above-described tetrohydrofuran is represented by the following structural formula.

（Ｂ）成分：
上記グリコールエーテル類は、下記一般式(III)で示されるものである。

(B) component:
The glycol ethers are those represented by the following general formula (III).

General formula (III)
R ³ —O (C _n H _2n O) _a —H
(However, R ^{3 is} an alkyl group having 1 to 10 carbon atoms, n: 2, 3 or 4, a: 1 ≦ a ≦ 30.)
Specifically, monoalkylene glycol mono, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, n-hexyl, i-hexyl, etc. Alkyl ether or dialkylene glycol monoalkyl ether; methyl, ethyl, n-propyl, i-propyl, n-butyl of polyethylene glycol (abbreviation "PEG") or polypropylene glycol (abbreviation "PPG") of trimer or more, Various polyalkylene monoalkyl ethers such as i-butyl, n-hexyl and i-hexyl can be preferably used.

(C) component:
As the phosphoric acid, phosphoric acid, metaphosphoric acid, phosphorous acid and salts thereof, particularly phosphoric acid (orthophosphoric acid) can be preferably used, but pyrophosphoric acid, hexametaphosphoric acid, polyphosphoric acid and salts thereof can also be used. Furthermore, phytic acid, organic phosphonic acid and salts thereof, organic phosphoric acids and salts thereof can be used.

  These compounds (drugs) are general-purpose and are available on the market.

  And as for the composition ratio of these each component, (B) component: 10-80 parts, (C) component: 10-40 parts are preferable with respect to (A) component: 100 parts, Furthermore, (A) component : The component (B): 20 to 60 parts and the component (C): 15 to 30 parts are preferable with respect to 100 parts.

  The concentration of each component in the aqueous dispersion medium varies slightly depending on the mode of the erasing liquid (correction liquid) (concentrated type or non-concentrated type) and the chemicals of each component, but is appropriately selected within the following range.

  In addition, although it is desirable to use demineralized water or ion-exchanged water as water to be used, it is generally acceptable to use it if it is tap water (tap water, well water, etc.).

Component (A) (dehydrated ring-closing saturated saturated five-membered ring compound)
... 0.1-60%, preferably 0.1-40%
(B) component (glycol ethers)
... 0.1-30%, preferably 0.1-20%
(C) component (phosphoric acids)
... 0.1-25%, preferably 0.1-15%
In addition, when the erasing liquid is prepared with an aqueous dispersion medium, the pH can be used as it is (usually pH 1 to 2). The eraser of the present invention can be used practically even if the pH is increased from the neutral range to the basic range from the standpoint of handleability (see Examples 4 to 9).

  The pH adjuster usable here is lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate and ammonium hydroxide as inorganic alkalis. Inorganic compounds of ammonium carbonate and ammonium hydrogen carbonate can be used as appropriate. In addition, organic compounds such as alkylamines, alkyldiamines, alkyltriamines, alkyltetraamines and aminoalcohols can be used as appropriate.

  Next, the present invention will be described more specifically with reference to comparative examples and conventional examples.

<Examples 1-9, Comparative Examples 1-6, and Conventional Examples 1-2>
In accordance with the compositions shown in Table 1 (Examples and Comparative Examples) and Table 2 (Conventional Examples), printing plate image part erasing solutions for various planographic printing were prepared. The unit is expressed in grams, and water (clean water) was added to finally make 1000 mL.

平版印刷版としては、下記ＰＳ版及びサーマルＣＴＰ版を標準条件で製版したものを使用した。

As the planographic printing plate, the following PS plate and thermal CTP plate made under standard conditions were used.

PS version: “VS” (trade name) manufactured by Fuji Photo Film Co., Ltd.
"VZ-Q" (trade name) manufactured by Fuji Photo Film Co., Ltd.
Thermal CTP version positive ...
“HP-F” (trade name) manufactured by Fuji Photo Film Co., Ltd.
“TP-R” (trade name) manufactured by Kodak Polychrome Graphics Co., Ltd.
“TP-U” (trade name) manufactured by Kodak Polychrome Graphics Co., Ltd.
And the test of each following item was done using the said eraser and plate material.

<Erase performance test>
The above five types of printing plates were immersed in each of the erasing solutions of Examples, Comparative Examples, and Conventional Examples for 5 minutes to observe image portion erasing performance.

  The evaluation items were as follows. The evaluation results are shown in Table 3.

        ○: The image part was completely erased.

        Δ: The image portion remained thin.

        X: The image part could not be erased at all.

＜消去確認テスト＞
上記画像消去後の各版を使用して印刷を行って消去確認テストを行った。

<Erase confirmation test>
Printing was performed using each plate after the image was erased, and an erase confirmation test was performed.

  The printing machine used was “DAIYA 1F-4” (trade name) manufactured by Mitsubishi Heavy Industries, Ltd., and the ink used was “TK HY Unity neo SOY MZ black” (trade name) manufactured by Toyo Ink Mfg. Co., Ltd. . As the dampening solution, “ASTRO MARK 3” (trade name) manufactured by Nikken Chemical Co., Ltd. was diluted to 2% with clean water.

  10,000 sheets were printed at a printing speed of 10,000 sheets / hour, and the presence or absence of ink adhesion in the erased image area was observed with a plate and printed matter.

  The evaluation items were as follows. The evaluation results are shown in [Table 4] for the state of the plate and [Table 5] for the state of the printed matter.

  The erasing performance and desensitizing performance of the above five printing plates on the image area were observed with a plate and printed matter after 10,000 sheets of printing.

        ○: No ink adheres to the erased image area.

        (Triangle | delta): There exists thin ink adhesion to the erased image part.

        X: Ink adhered to the erased image area.

＜試験結果考察＞
グリコールエーテル類（成分（Ｂ））を含有しない比較例１〜３と脱水縮合型飽和複素環群化合物（成分（Ａ））を含有しない４〜５、及び、リン酸類（成分（Ｃ））を含有しない比較例６は、各印刷版の画像に対する消去性能及び不感脂化性能に問題があることが確認できた。

<Examination of test results>
Comparative Examples 1 to 3 that do not contain glycol ethers (component (B)), 4 to 5 that do not contain dehydration condensed saturated heterocyclic group compound (component (A)), and phosphoric acids (component (C)) It was confirmed that Comparative Example 6 not containing had a problem in erasing performance and desensitizing performance with respect to the image of each printing plate.

  Conventional Examples 1 and 2 have good erasing performance and desensitizing (hydrophilization) performance for images on each printing plate, but are fluorinated as a poisonous medicine and poisonous substance by the Deleterious Substances Control Law. Since it contains hydrogen or a fluorine compound, there is a problem in work safety when erasing the image on the entire printing plate.

  That is, the examples of the image part erasing liquid of the lithographic printing plate according to the present invention are excellent in any evaluation items, laws and regulations, and work safety, and suitable as a lithographic printing plate image part erasing liquid. It was found to be excellent. Further, as shown in Examples 4 to 9, it was confirmed that the entire image area can be erased even when the erasing solution pH is in a neutral region or a basic region.

Claims (4)

A lithographic printing plate correction solution comprising the following components (A), (B) and (C) as essential components in an aqueous dispersion medium.
(A) component:
1) N-alkylpyrrolidones (γ-lactams) represented by the following general formula (I):
Formula (I)

(However, R ^1: hydrogen, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group or a hydroxyalkyl group having 1 to 4 carbon atoms having 4 to 8 carbon atoms)
2) γ-lactones represented by the following general formula (II), and general formula (II)

(Where R ^{2 is} hydrogen or an alkyl group having 1 to 12 carbon atoms)
3) One type or two or more types selected from the group of dehydrated ring-closed saturated hetero five-membered ring compounds of tetrahydrofuran.
Component (B) One or more selected from the group of glycol ethers represented by the following general formula (III).
General formula (III)
R ³ —O (C _n H _2n O) _a —H
(However, R ^{3 is} an alkyl group having 1 to 10 carbon atoms, n: 2, 3 or 4, a: 1 ≦ a ≦ 30.)
Component (C) One or more of phosphoric acids (including phosphoric acid, polyphosphoric acid, organic phosphoric acid and salts thereof). R ¹ in the general formula (I) is an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group or a hydroxyethyl group, R ² in the general formula (II) is hydrogen, and the general formula (III) The correction liquid for lithographic printing plates according to claim 1, wherein R ^{3 is} an alkyl group having 2 to 6 carbon atoms, n = 2 or 3, a: 1 or 2.   Each component is contained in a composition of (B) component: 10 to 80 parts by mass and (C) component: 10 to 40 parts by mass with respect to 100 parts by mass of (A) component. Item 3. A lithographic printing plate correction solution according to item 1 or 2.   Each component is contained in a composition of (B) component: 20 to 60 parts by mass and (C) component: 15 to 30 parts by mass with respect to 100 parts by mass of (A) component. Item 3. A lithographic printing plate correction solution according to item 1 or 2.