KR100318092B1 - Naphtoquinone-diazide Ester Photosensitive Material for PS Plate Use - Google Patents

Abstract

The present invention relates to a naphthoquinone-diazide (NQD) -based photosensitive material for PS plates, wherein dehydration of hydroxybenzophenone derivatives in which 2-diazo-naphthoquinone-5-sulfonyl chloride and methoxy group are introduced is carried out. The photosensitive material according to the present invention exhibits excellent solubility, sensitivity, and resolution, and is low in production cost.

Description

Naphtoquinone-diazide ester photosensitive material for PS plate

The present invention relates to a naphthoquinone-diazide (NQD) photosensitive material for PS plates, and more particularly, to a naphthoquinone which is a photosensitive resin used as a photosensitive material of a positive PS (Pre-sensitized) plate. A naphthoquinone- (1,2) -diazide-5-sulfonic acid ester that is a derivative of diazide (NQD).

The most important functions of the photosensitive polymer are the image-making function and the thin film photo-curing function. It is used in various ways such as an image forming photoresist, a photosensitive material for printing plate (PS plate, a printing resin plate), a photosensitive printing ink, and a photosensitive adhesive.

General properties required for the photosensitive resin include high sensitivity, high resolution, good adhesion to the substrate and thermal stability, and also include simple manufacturing and application processes, and should not contain impurities that adversely affect the economy.

Photosensitive resins can be classified into positive type and negative type, and the type that is irradiated with light is not dissolved in the developer when developing due to crosslinking or polymerization reaction.The negative type is decomposed and dissolved in developer. Forms are called positive photosensitive resins.

In general, the positive type has the disadvantage that it is less sensitive to the exposure time because it is less adhesive and the film is weaker and alkali is used as a developer than the negative type, but the coating foil is stable, it is not sensitive to oxygen during exposure, and the stability of resolution and heat is poor. It is excellent, it does not cause swelling during development, and after exposure, development and drying, it is excellent in durability against etching and is used more.

In this case, a suitable polymer (matrix resin or base resin) is used in combination with a photoactive compound called PAC to modify the film formation, coating properties, and solubility.

Naphthokinone diazide-noblock resin, a photosensitive resin used as a photoresist for positive PS (Pre-Sensitized) plates, is a representative photosensitive material of positive type.

The naphthoquinone diazide derivative is mixed with a noblock phenolic resin, applied to a support, dried, and manufactured to form a photosensitive plate, which is photolyzed to form a highly reactive ketene, which is reacted with nitrogen gas and ketene A positive image is formed by a reaction mechanism in which the solubility is increased in the developer by the carboxylic acid formed by reaction with water.

Novolac resins, which are commonly used, are thermoplastic resins of cresol-formaldehyde condensers reacted with acid catalysts, have adhesiveness and thermal stability to substrates (silicon and aluminum), and are used in photolithography processes. Not only is it resistant to compounds such as etch solutions, but it also absorbs light at 436 nm or 265 nm wavelengths, causing photochemical reactions such as naphthoquinone azide. Because it does not interfere at all, it is well suited as a base resin for photoresist, and cresol resins may be used instead to improve physical performance.

In particular, as a photosensitive material of positive-type PS plate used as a printed board, NQD / novolak-based resin is greatly influenced by the structure and mechanical properties of the polymer to have the most important printing strength of the printed plate. Naphthoquinone diazide is widely used as a positive photoresist for processing highly integrated circuit semiconductors due to deformation of the resin.

Importantly, there are photosensitivity characteristics by substituents, and those with large photosensitivity are mainly used. The photosensitivity is in the 5-position of naphthoquinone diazide (NQD) having an absorption wavelength region of 350-400 nm corresponding to the halogen lamp generally used. Use is made of sulfonyl (-SO _2- ) groups.

An important physical property of PAC is that the absorption spectrum region should have good agreement with the emission spectrum of the Halogen Lamp and good photobleaching, good compatibility with the matrix resin, and also need thermal stability.

PAC requires physical properties such as good solubility, sensitivity and resolution due to subsequent processes. In general, the problem of PAC in which NQD is substituted for hydroxybenzophenone derivative is that it is not so easy at room temperature so crystallization is not easy to manufacture PS plate. For this purpose, the hydroxy group is left by controlling the amount of NQD substituted for hydroxy group. The method of increasing solubility was used, but problems of this method include the disadvantage of increasing the amount of PAC needed to have sufficient developing ability and a problem of unit price increase due to the increase of benzophenone usage.

The present invention is to solve the above problems, to provide an NQD-based photosensitive material excellent in solubility, sensitivity and resolution. It is still another object of the present invention to provide an NQD-based photosensitive material having low production cost by reducing the amount of benzophenone required to achieve developing ability.

1 is a UV spectrum of 2-Hydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5],

2 is a UV spectrum of 2,2'-Dihydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5],

3 is an NMR spectrum of 2-Hydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5],

4 is an NMR spectrum of 2,2'-Dihydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5],

5 is a positive image of the PS plate according to the present invention,

6 is a five-dot image of the PS plate according to the present invention.

The photosensitive material of the present invention is characterized by condensation polymerization of a hydroxybenzophenone derivative in which a methoxy group is introduced into NQD and benzophenone. Preferred hydroxy benzophenone derivatives are 2-hydroxy-4-methoxybenzophenone and 2,2'-dihydroxy-4-methoxybenzophenone.

Hereinafter, the present invention will be described in detail.

The NQD-based photosensitive material of the present invention is synthesized NQD-Cl from NQD-Na, and the hydroxybenzophenone derivatives in which the synthesized NQD-Cl and methoxy group are introduced, 2-hydroxy-4-methoxybenzophenone and 2,2'-dihydroxy- Polycondensate 4-methoxybenzophenone. If they are used as ballast, the amount of PAC used to impart developing ability can be significantly reduced.

The sensitivity of 2,2'-Dihydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5] is similar to that of NQD-ester substituted with 3 or 4 NQD.

UV absorption before exposure of the photosensitive liquid according to the present invention shows a characteristic absorbance of 320-420nm, the maximum absorption wavelength shows a good photobleaching degree of about 350nm.

Embodiments of the present invention are as follows.

4,4'-dihydroxybenzophenone, 2,4'-dihydroxybenzophenone, 2,3,4'-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,3,4,4, which are hydroxybenzophenone derivatives to be compared with the ballast used in the present invention 2-diazo-1-naphthoquinone-5-sulfonyl acid-ester (NQD-ester) was synthesized by condensation of '-tetrahydroxybenzophenone and 2,2', 4,4'-tetrahydroxybenzophenone with NQD-Cl.

The structural formula of the hydroxybenzophenone derivative used is shown in 1-8 below.

In order to examine the possibility of photosensitive materials that can be used in the printing process, the synthesized NQD-ester and the matrix novolac resin were mixed at a known weight mixing ratio. The exposure time was compared and measured, and the light absorption wavelength region, absorbance, photobleaching [8], and relative sensitivity of these composites were measured to compare photosensitive characteristics.

<Example 1-2 and Comparative Example 3-8>

1. Reagents and Materials

Sodium-2-diazo-1-naphthoquinone-5-sulfonate and novolac resin (MW = 7,000) were supplied by Darani Co., Ltd., and chlorosulfonic acid was used as a ballast hydroxybenzopenone derivative without purification. 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, and 2,3 ', 4,4'-tetrahydroxybenzophenone are TCI's reagent grade 4,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2, 3,4-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone and 2,2 ', 4,4'-tetrahydroxybenzophenone were used without purification from Aldrich's reagent. Dioxane, butylcellusolve, and γ-butyrolactone were used as primary reagents.

2. Synthesis of PAC and Preparation of Photoresist

1) Synthesis of 2-Diazo-naphthoquinone-5-sulfonyl chloride

1,000 g (8.58 mol) of chlorosulfonic acid was added to a 1,000 ml three-necked flask and 150 g (0.55 mol) of sodium-2-diazo-napthoquinone-5-sulfonate was slowly added dropwise while maintaining the temperature below 7 ° C. After the dropping was completed, the mixture was stirred for about 30 minutes at room temperature, and the reaction mixture was reacted at 58 ° C for 12 hours. After the reaction was completed, the temperature of the reactant was lowered to room temperature, and then slowly dropped into ice water having a volume ratio of 10 times. The resulting precipitate was filtered under reduced pressure, washed with water until neutral, and dried under reduced pressure to obtain 118 g of 2-diazo-naphthoquinone-5-sulfonyl chloride as yellow crystals (yield 80).

2) Synthesis of 2-Diazo-1-naphthoquinone-5-sulfonyl acid ester

Sodium-2-diazo-napthoquinone-5-sulfonyl chloride and each ballast were dissolved in a mixed solution of dioxane and distilled water (2: 1) and the temperature was kept below 7 ° C. While stirring, the 20Na ₂ CO ₃ solution was slowly added dropwise until the pH became 9 or more. The reaction was slowly added to distilled water three or more times to obtain a precipitate. The precipitate was filtered under reduced pressure, washed with water until neutral, and dried under reduced pressure to obtain yellow crystal NQD-ester. The amount and yield of NQD-Cl and each ballast used are shown in Table 1 below.

division Ballast NQD-Cl Yield () Hydroxybenzophenone derivatives Weight (g) Weight (g) Example 1 2-Hydroxy-4-methoxybenzophenone 10 30 91 Example 2 2,2'-Dihydroxy-4-methoxybenzophenone 9 24 80 Comparative Example 1 2,4-Dihydroxybenzophenone 9 24 65 Comparative Example 2 4,4'-Dihydroxybenzophenone 9 24 84 Comparative Example 3 2,3,4-Trihydroxybenzophenone 8 47 95 Comparative Example 4 2,4,4'-Trihydroxybenzophenone 8 47 90 Comparative Example 5 2,3,4,4'-Tetrahydroxybenzophenone 9 42 90 Comparative Example 6 2,2'4,4'-Tetrahydroxybenzophenone 9 42 89

3) Preparation of PS plate and confirmation of photosensitive characteristics

3-1) Dissolution Characteristics of NQD-ester

In order to investigate the dissolution characteristics of NQD-ester, the solubility of γ-butyrolactone, which is a commonly used solvent and NQD-ester, was measured at room temperature and at 60 ℃. The results are shown in Table 2 below.

division NQD-ester Methy1cellusolve Buty1cellusolve γ-Butyrolactone Example 1 2-Hydroxy-4-methoxybenzophenonebis [DIAZO-2,1,5] △ △ ○ Example 2 2,2'-Dihydroxy-4-methoxybenzophenonebis [DIAZO-2,1,5] ○ ○ ○ Comparative Example 1 2,4-Dihydroxybenzophenonebis [DIAZO-2,1,5] ○ ○ ○ Comparative Example 2 4,4'-Dihydroxybenzophenonebis [DIAZO-2,1,5] × × △ Comparative Example 3 2,3,4-Trihydroxybenzophenonebis [DIAZO-2,1,5] ○ ○ ○ Comparative Example 4 2,4,4'-Trihydroxybenzophenonebis [DIAZO-2,1,5] ○ ○ ○ Comparative Example 5 2,3,4,4'-Tetrahydroxybenzophenonebis [DIAZO-2,1,5] ○ ○ ○ Comparative Example 6 2,2'4,4'-Tetrahydroxybenzophenonebis [DIAZO-2,1,5] × × △

○: solvent at room temperature, △: soluble at 60 ℃

×: insoluble

3-2) Manufacturing of PS Plate

NQD-esters synthesized with the matrix resin were added at a weight ratio of 4: 1 to a 1: 1 solvent of γ-butyrolactone and butyl cellusolve. After stirring for a long time and filtered with a filter to prepare a photosensitive liquid.

The conditions of Formulation are shown in Table 3. Al plate used as a support was used electrolytic polishing treatment to increase the adhesiveness when the photosensitive agent coating (coating) on the surface. The filtered photosensitive solution was applied to the PS plate while adjusting to a thickness of 2 μm by a spin coater. Since the solvent remains in the coated photoresist, it is an obstacle to exposure. Thus, a PS plate was prepared by drying at 100 ° C. to 120 ° C. for 60 seconds to completely remove the solvent. The exposure was performed for 20 seconds using a 3kW halogen lamp of USHIO.

The development was carried out by dipping the PS plate in a deionized water and an aqueous solution of volume ratio of 1: 8 while maintaining the temperature of 25 DEG C in a PS plate, stirring the bath, and developing the PC plate in deionized water. Was limited to within 60 to 100 seconds.

Water was washed on the washed PS plate and dried for 60 seconds at 100 ° C. by hard baking to remove the remaining developer.

Weight Weight Novolac resin 20 g 30 PAC 5 g 7.7 Solvent 4.0g 62 Dye (crystal violet) 0.2 g 0.3

3-3) Measurement of Photobleaching

The PS plate was exposed to light at 10 second intervals using a Halogen Lamp, dissolved in acetonitrile, and then measured with a SCINCO UV S-2040 spectrometer to confirm photobleaching. .

3-4) Image Formation Check and Sensitivity Measurement

Exposure time was developed using a dot film on the PS plate and developed to determine a developing time at which a minimum dot was formed. The generated pattern was confirmed using an image analyzer.

The sensitivity was calculated using the gray scale method, which is commonly used.

S1 / S0 = 100.102 (k-j)

Where S ₀ = reference sample sensitivity

S ₁ = control sample sensitivity

Relative sensitivity was calculated | required by the singular difference (k-j) of a reference sample and a sample to measure.

The results are shown in Table 4 below.

division NQD-ester Step number time (sec) Number of NQD Relativesensitivity Standard (commercial product) 6 60 100 Example 1 2-Hydroxy-4-methoxybenzophenonebis [DIAZO-2,1,5] 8 60 One 160 Example 2 2,2'-Dihydroxy-4-methoxybenzophenonebis [DIAZO-2,1,5] 10 60 2 256 Comparative Example 1 2,4-Dihydroxybenzophenonebis [DIAZO-2,1,5] 8 60 2 160 Comparative Example 2 4,4'-Dihydroxybenzophenonebis [DIAZO-2,1,5] 9 60 2 202 Comparative Example 3 2,3,4-Trihydroxybenzophenonebis [DIAZO-2,1,5] 9 60 3 202 Comparative Example 4 2,4,4'-Trihydroxybenzophenonebis [DIAZO-2,1,5] 10 60 3 256 Comparative Example 5 2,3,4,4'-Tetrahydroxybenzophenonebis [DIAZO-2,1,5] 10 60 4 256 Comparative Example 6 2,2'4,4'-Tetrahydroxybenzophenonebis [DIAZO-2,1,5] 9 60 4 202

4) Analysis and Instrument

A 300 MHz ¹ H NMR (VARIAN UNITY plus 300 spectrometer) was used to confirm synthesized NQD-Cl and NQD-ester. DMSO-d ₆ was used as a solvent and TMS was used as an internal standard sample. For IR spectrum analysis, pellets were prepared with KBr and NICOLET 800 spectrophotometer was used, and SCINCO S-2040 UV spectrophotometer was used to investigate the change of absorption peak according to absorption area, maximum absorption peak (λ _max ) and UV exposure. USHIO's 3kW metal halide lamp was used as the light source of the UV exposure machine and exposed at a position 40 cm away from the light source.

3. Results

1) Synthesis confirmation of compound

1-1) Confirmation of 2-Diazo-naphthoquinone-5-sulfonyl chloride

IR analysis was performed to see the results of the synthesis of NQD-Cl. In the IR spectrum, C = O characteristic absorption band of naphthoquinone at 1614 cm ^-1 and C = N = N characteristic absorption band at 2122 cm ^-1 and -SO ₂ -characteristic absorption band at 1264 cm ^-1 , respectively. Hydrogen peaks attached at positions 3 and 4 of the benzene ring of the NQD group appeared at ppm and 7.62 ppm, indicating the synthesis of NQD-Cl. The UV spectrum showed a characteristic absorption band of 320-420 nm and the maximum absorption wavelength was 354.9 nm.

1-2) Confirmation of 2-Diazo-1-naphthoquinone-5-sulfonyl acid ester

IR analysis was performed to see the results of the synthesis of NQD-ester.

IR spectrum results of 2-Hydroxy-4-methoxybenzophenone bis [DIAZO-2, 1, 5] and 2,2'-dihydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5], 3500 cm from the IR spectrum of the hydroxybenzophenone derivative The characteristic absorption band of -OH group of ^-1 disappears and the C = O characteristic absorption band of naphthoquinone and benzophenone at 1614 cm ^-1 in the IR spectrum of each NQD-ester, and the C = N = N characteristic absorption band at 2120 cm ^-1 and 1261 In cm ^-1 , the characteristic absorption band of -SO ₂ -appeared, respectively.

¹ H-NMR analysis was performed to confirm synthesized NQD-ester. Analysis of ¹ H-NMR results by dissolving NQD-ester in DMSO-d ₆ showed hydrogen peaks at positions 3 and 4 of the benzene ring of the NQD group at 8.05 ppm and 7.54 ppm, and benzophenone at 6.73 ppm. From the hydrogen peak at position 3 of the benzene ring of and the methoxy hydrogen peak at 3.82 ppm, 2-hydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5] was synthesized. Hydrogen peaks attached at positions 3 and 4 of the benzene ring of the NQD group are shown at ppm and 7.99 ppm, and hydrogen peaks attached at position 3 of the benzene ring of the benzophenone at 6.73 ppm and methoxy hydrogen peaks of 3.82 ppm are shown. It was found that 2,2'-dihydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5] was synthesized.

2) Characterization of Photosensitive Agent

2-1) Dissolution Characteristics

As a result of the dissolution characteristics, it was confirmed that the dissolution characteristics result was changed by the structure of NQD-ester.

Among the NQD-esters, in which the hydroxy group of benzophenonne was completely substituted with NQD grouop, the symmetric ester showed poor solubility in organic solvents. 1,5] showed good dissolution characteristics.

2-2) Photochromicity measurement result

In order to measure the photobleaching, the UV spectrum was investigated by exposure at 10 second intervals. As a result, one or two NQD substitutions resulted in the lowest absorbance at 30 seconds, and three or four substitutions reached the lowest in 40 seconds. I could see that.

1 and 2 show UV spectra, and the light of 2-hydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5] and 2,2'-dihydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5] It shows the degree of fading and shows the image formation time when the exposed part is completely changed by the developing solution.

2-3) Image Formation Check

As a result of confirming the dot reproducibility using a dot film by applying the time of fully exposed and photoconversion to each photosensitive resin obtained from the photobleaching degree result by UV spectrum, the dot reproducibility was better than that of commercial photosensitive resin. .

FIG. 3 is a result of scanning a positive image obtained by exposing and developing a PS plate manufactured using 2,2'-dihydroxy-4-methoxybenzophenone bis [DIAZO-2,1,5]. FIG. The result was confirmed using an image analyzer.

As can be seen from the above examples and comparative examples, NQD-esters having a symmetrical structure show poor solubility, but NQD-ester having a methoxy group introduced shows suitable dissolution properties for the production of PS plates. UV absorption of before shows a characteristic absorption band of 320 ~ 420nm, the maximum absorption wavelength is about 350nm and shows a good light fading, and shows good image forming function during development after exposure.

Claims (2)

A naphthoquinone-diazide photosensitive material for PS plates, which is obtained by condensation polymerization of 2-diazo-naphthoquinone-5-sulfonyl chloride and a hydroxybenzophenone derivative in which a methoxy group is introduced. The hydroxybenzophenone derivatives having a methoxy group introduced therein include 2-hydroxy-4-methoxybenzophenone and 2,2'-dihydroxy-4-methoxybenzophenone. A naphthoquinone-diazide photosensitive material for PS plates characterized by the above-mentioned.