JPS602945A - Photopolymerizable composition - Google Patents

Abstract

PURPOSE:To obtain a photoresist with superior stability by using an 0-t-butylphenol deriv. and a heterocyclic thiol compound as a stabilizer. CONSTITUTION:An 0-t-butylphenol deriv. such as 2-mercaptobenzothiazole, 2- mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercaptothiazoline, 2-mercaptobenzotiazoline, 2-mercaptooxazoline or 2-mercaptoimidazoline and a heterocylic thiol compound are used as a stabilizer for a photopolymerizable composition contg. an ethylenic unsatd. compound, a polymer binder and a photopolymn. initiator.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel photopolymerizable compositions. In particular, the present invention relates to a photopolymerizable composition suitable for photoresists having excellent stability.

In recent years, various photosensitive resins have been used in the photoresist field, and in particular, photopolymerizable photosensitive materials that utilize photoradical generation are widely used as the most useful materials. Practically important properties required of these light-sensitive materials include initial performance, thermal theory, and quality stability, especially storage stability and stability during actual processing. In particular, photopolymerizable photosensitive materials in the form of dry films used for producing printed wiring boards have conventionally not had sufficient quality stability. This dry film photopolymerizable photoresist (hereinafter abbreviated as dry film) usually uses a laminated structure material consisting of three layers: a flexible support, a photopolymerizable layer, and a protective film. To explain the manufacturing process of a printed wiring board using this, first, the protective film is peeled off, the exposed photopolymerizable layer is laminated on the surface of the printed circuit board, and after image exposure, the flexible support is removed and liquid development is performed. However, a method is adopted in which a resist image is formed and finally an etching or plating process is performed.

The inventors of the present invention have conducted studies focusing on the storage stability of the dry film before the lamination process and the quality stability after lamination, that is, when it is in close contact with the copper metal surface, which tends to be chemically active. , which led to the present invention.

That is, the gist of the present invention is to provide a photopolymerizable composition comprising an ethylenically unsaturated compound, a binder polymer, a photopolymerization initiator, and a stabilizer, wherein the stabilizer is at least one O-tert-butylphenol derivative. and at least one type of heterocyclic thiol compound.

Next, the photopolymerizable composition of the present invention will be explained in detail.

The present inventors have demonstrated that a specific stabilizer can be used in a dry film state of a photopolymerizable composition, i.e., held in a side winch shape by two polymer sheets, and in a state in which it is laminated on a printed circuit board, i.e., in a single sheet. It has been found that the initial properties are well maintained in both the polymer seed and the copper sheet when similarly held in a sand winch state. This stabilizer is composed of at least two components, the first of which is an O-tert-butylphenol derivative. These may be commercially available antioxidants. Specific examples include 2.6-ditertiarybutylphenol, 2j-ditertiarybutyl-'l! r-cresol (BHT), tetrakis[methylene-(3,!-ditert-butyl-hydroxy-hydrocinnamate)]methane (rganox10/θKbm), x
tylene glycol bis(3,!-di-tert-butyl-hydroxy-hydrocinnamate), ≠, ri-thiobis(-tert-butyl-3-methylphenol), ≠゛-methylenebis6-tertiary butylphenol)%”, ≠-methylenebis(6-tert-butyl-〇-cresol), /, /, J-tris(S-
Tert-butyl-μm hydroxy-2-methylphenyl)butane 1. z, g, 6-tris(3,j-ditertiarybutyl-≠-hydroxybenzyl)mesitylene, /
, A~bis(3,j-ditertiarybutyl-≠-hydroxyphenylacetoxy)hexane, x-(p-hydroxy-3,j-ditertiarybutylanilino)-1,
≠-bis(rl-octylthio) −/, 3. ! r −
Triazine, n-octadecyl-3-(!'-Hi)'
Loki' / -3,! '-ditert-butylphenyl) propionate and diethylguhydroxy-3,
Z-cytase lyptyl benzyl phosphonate is mentioned. Any of these can be used successfully.

The second component that makes up the stabilizer is a heterocyclic thiol.

Specific examples include Komelkabutobenzthiazole, Komelcaptobenzoxazole, Komelcaptobenzimidazole, Komelkabutothiazoline, λ-mercaptobenzthiazoline, and Komelkabutogisazoline.

Komelcaptobenzoxazinone, Komelkabutimidazoline, -monomercaptobenzimidalin, 3-mercapto-/, 2.4'-) lyazole, -monoamino! -Mercapto-/, 3. Examples include Hiro-thiadiazole and λ-mercaptalk (3H) quinazolinone. Among them, komelcaptobenztheazole, komelkabutobenzoxazole, 2-mercaptobenzimidazole, and komelkabutothiazoline are preferred. Each component of the stabilizer is present in an amount of 0.0 to zM, preferably 0.1% by weight, based on the total amount of ethylenically unsaturated compound and binder polymer in the photopolymerizable composition. or /Mi% can be added.

Other components of the photopolymerizable composition of the present invention may be prepared using conventionally disclosed techniques, for example, Japanese Patent Publication Akihiro J-23, 23.
No. 1, Special Public Shoj Gu No. 23937.

A wide variety of components may be used, including those described in Japanese Patent Publication No. 2003-112021.

Preferred ethylenically unsaturated compounds are (meth)acrylic acid-based unsaturated compounds; for example, esterified compounds of acrylic acid or methacrylic acid and aliphatic or aromatic polyhydroxy compounds are suitable. Particularly preferably,
For example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, tetradiethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, dipenta Examples include erythritol hexaacrylate, glycerol triacrylate, and bisacryloxyethyl phosphate. The ethylenically unsaturated compound has a total gravity of 1 as mentioned above, with a concentration of 20 to SO
Used in amounts of % by weight.

Preferred examples of the binder polymer include, for example, styrene/(meth)acrylic acid ester/(meth)acrylic acid copolymer, styrene/(meth)acrylic acid ester/maleic anhydride half ester copolymer, ( Examples include meth)acrylic acid ester/(meth)acrylic acid copolymer and vinyl acetate/crotonic acid copolymer. The binder polymer is used in an amount of 50% by weight to 0 gOM based on the total amount mentioned above.

Examples of photopolymerization initiators include benzoin ether,
Those containing anthraquinone, benzophenone, benzyl, Michler's ketone, bisimidazole, etc. alone or in a mixed system may be used. The amount used is 0.00% based on the same total weight as above. The photopolymerizable composition of the present invention, in which / to / j tun@φ, preferably 0.3 to 5 folds, may further contain an exposed visible imaging agent. As the exposure visible image agent, conventionally known starting color systems or photobleaching systems can be used, but a preferred system is a system containing a compound having a halogenated hydrocarbon group and a leuco form of a triphenylmethane dye. Examples of the former include carbon tetrabromide, methylphenylsulfone, tristrichloromethyl-8-triazine, tristribromomethyl-8-)
Examples of the latter include leuco crystal violet, leucomalachite green, leuco victoria blue, and leucor rosa niline.

In addition, known additives such as colorants and plasticizers may be added as necessary.

When the photopolymerizable composition comprising the above-mentioned components is used as a photosensitive layer for dry film, polymer sheets are placed on both the front and back surfaces of the photosensitive layer. Examples of the polymer sheets include polyethylene terephthalate, polyvinyl chloride, etc. ,
Polyvinylidene chloride, polystyrene, polyvinyl acetate,
Examples include sheets made of polyethylene, polypropylene, WFUI cellulose, polyvinyl alcohol, and the like.

The photopolymerizable composition of the present invention can be applied not only to dry films but also to photoresists for corrosion plates, printing plates, image duplication fields, and the like.

Next, the present invention will be specifically explained using Examples and Comparative Examples, but the present invention is not limited thereto unless it exceeds the gist thereof.

Examples/~j A photosensitive stock solution having the following composition was prepared, and the stabilizer of the present invention shown in Table 1 was added to the solid content of the photosensitive stock solution in an amount of O-tertiary phenol derivative O, S weight % and heterocyclic ring. A sample photosensitive solution was prepared by adding thiol OOS by weight. This was coated and dried on a polyethylene terephthalate sheet with a thickness of 23 μm to a dry film thickness of SO μm, and then a polyethylene sheet with a thickness of 25 μm was laminated on the surface of the photosensitive layer to prepare a dry film sample.

[Photosensitive stock solution]

A copolymer consisting of 10% by weight of methyl methacrylate/aop% by weight of ethyl acrylate/20% by weight of methacrylic acid (diluted with 950% by weight of methyl ethyl ketone,
000cp8)・・・・・・・・・6.0?・ Trimethylolpropane triacrylate...
・・・・・・・・・／, J'P '・ Tetraethylene glycol diacrylate ・・・・・・・・・・・・0.
1 f Benzyl ・・・・・・・・・・・・gr・ Michler Ketone ・・・・・・・・・・・・ 2mg・
Tribromomethylphenylsulfone・・・・・・・・・
・・・rrmg ・ Leucocrisdol violet ・・・・・・・・・・ grmy ・ Victoria Pure Blue ・・・・・・・・・・・・
・ 2 m9・ Methyl ethyl ketone ・・・・・・・
... l≠, o 1 Three pieces of the same dry film sample were prepared from the same sample photosensitive stock solution, and each was evaluated for its initial characteristics, characteristics after 20 days of hydrothermo treatment in the dry film state, and lamination on a printed circuit board. The specimens were subjected to various measurements and evaluations of characteristics after 6 days of hydrothermo treatment. The hydrothermo treatment conditions were μoC%f O% RH.

Evaluation items include resolution in etching characteristics, presence or absence of background contamination (etching fog), color tone density change R due to dark reaction (vs. initial value), photochromic density difference in exposed visible image characteristics and its rate of change (vs. initial value). ). The optical density was measured using a densitometer (Macbeth HD'-j, /l), and the etching characteristics and exposure visible image quality were measured by laminating the printed circuit board with a mask film, step tablet, and resolution chart, and using a high-pressure mercury lamp light source. i i
After irradiating the light amount of o rn7/ad and measuring the exposed area and the remaining 5 light areas by 13 degrees, follow the usual method/with a sodium thicarbonate aqueous solution:! J! The image was evaluated by etching with an aqueous solution of ferric chloride. The evaluation results are shown in Table-2.

Comparative Examples 1 to 3 The additives shown in Table 7 were added to the photosensitive stock solution described in Example 1, and Example 1 and Intermediate Mixture 1 were evaluated in the same manner as described above without any additives, and the results are shown in Table 7. .

Comparative Example Hiroshi, j Commercially available dry films, Product A and Product B, were evaluated in a similar manner and the results are shown in Table 2.

From the evaluation results, it is understood that the stabilizer of the present invention exhibits well-balanced stability with respect to each evaluation item including good etching properties during lamination.

Table-/

Claims (1)

[Claims] (1) A photopolymerizable composition comprising an ethylenically unsaturated compound, a binder polymer, a photopolymerization initiator, and a stabilizer, wherein the stabilizer comprises at least one 0-tert-butylphenol derivative and at least one heterocyclic thiol compound. A photopolymerizable composition comprising one or more.