JPH0477503A - Photopolymerization initiator - Google Patents

Abstract

PURPOSE:To obtain a new photopolymerization initiator having susceptibility in a wide wavelength from an ultraviolet range to a near infrared range, containing a photosensitive material such as recording medium shown by a specific formula. CONSTITUTION:A photopolymerization initiator (e.g. compound represented by formula II) and shown by the general formula I [D' is cation residue; R<1> to R<3> are alkyl, alkenyl, alkynyl, alicyclic, aryl(oxy), heterocyclic and R<1> and R<2> may be bonded to form cyclic compound]. The initiator, for example, is obtained by reacting triphenylborane with sodium cyanide under heating at 150 deg.C in the case of cyanotriphenyl borate of formula II.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is directed to a novel light source that is sensitive to a wide range of wavelengths from the ultraviolet region to the near-infrared region and is contained in photosensitive materials such as recording media. Related to polymerization initiators.

[Prior Art] Conventionally, there are many types of photopolymerization initiators contained in photosensitive materials, which are optical recording media, such as azo compounds, organic sulfur compounds, carbonyl compounds, and redox systems using ferric ions. The compounds include good stability over time and sensitivity to light, etc.
Furthermore, organic carbonyl compounds are generally used because they are easy to synthesize.

However, with the remarkable progress in laser technology in recent years, there has been a desire to perform various types of recording, such as resist patterning and plate making, using laser light, especially semiconductor laser light, which is inexpensive and compact. Since semiconductor laser light cannot be below 600 nm,
In place of the conventional photopolymerization initiators whose photosensitive wavelength range is 450 nm or less, research has been conducted on new photopolymerization initiators that are sensitive to light in a relatively long wavelength range of 600 nm or more. There is.

Up to now, for example, systems that combine biryllium dyes and peroxides have achieved longer wavelengths in the photosensitive wavelength range, but because they contain peroxides, they have the disadvantage of poor stability over time. have.

Further, JP-A-62-143044 discloses a cationic dye-borate anion complex having a photosensitive wavelength range of 500 nm or more as a photopolymerization initiator. However, this complex had the disadvantage of being inferior in photosensitivity and stability over time.

[Problems to be Solved by the Invention] The present invention is characterized in that it provides a photopolymerization initiator comprising a novel borate salt that is sensitive to a wide range of wavelengths from the ultraviolet region to the near-infrared region. The object of the present invention is to provide a photopolymerization initiator that has excellent photosensitivity and stability over time.

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors have obtained the photopolymerization initiator of the present invention.

That is, the present invention provides the following general formula (1) [In the above formula (1), De is a cationic residue, RIR2R
3 are the same or different, and are an alkyl group, an alkenyl group, an alkynyl group, an alicyclic group, an aryl group, an aryloxy group,
Aralkyl group selected from the group consisting of heterocyclic groups. Furthermore, R1 and R2 may combine to form a ring compound]
It is a photopolymerization initiator represented by

The photopolymerization initiator of the present invention can be used in printing inks, resist materials, etc., or in Japanese Patent Publications No. 42-14344,
The present invention is applicable to media used in the image forming method described in Japanese Patent No. 4-20852 and the like.

Examples of the cationic residue represented by DΦ of the compound of general formula (1) include metal ions such as Li'', Na', and K'', and organic cationic dyes. Examples of organic cationic pigments include cyanine pigments, merocyanine pigments,
Examples include polymethine dyes having anilino groups, azulene dyes, biryllium dyes, triarylamine dyes, azo dyes, styryl dyes, fluorene dyes, and aminovinyl dyes.

To give a specific example, examples of cyanine dyes include:
1,1°, 3,3.3″, 3-hexamethyl-2,2′
- Indocarbocyanin, 1. l', 3.3.3
', 3'-hexamethyl-2,2'-indodicarbocyanine, l, 1', 3,3゜3.3'-hexamethyl-2,2'-)dicarbocyanine, 1,1-diethyl- 3,3,3°,3°-tetramethyl-2,2'
-indocarbocyanine, 1.1 -dipropyl-3,
3,3'.

3'-tetramethyl-2,2°-indocarbocyanine, 1.1"-jethoxyethyl-3,3,3°13"-
Tetramethyl 2.2゛-indodicarbocyanine, (
[3-(1,3,3-trimethyl-2-indriven)
methylidene]-2-chloro-1-cyclopent-1-yl)-methylidine-1,3,3-trimethyl-2-indolium, [(3-ethyl-benzo-1-thiazolizone)methylidene-2-chloro-1- cyclopent-1-yl]-methylidene-3-ethylbenzo-1-thiazolium, 3,3°-diethyl-2,2″-thiacyanine, 3
．． 3-diethyl-2,2-thiacarbocyanine, 3.3
'-diethyl-2,2°-thiadicarbocyanine,
Examples include (1-methyl-4-quinolino)-(1,3,3-trimethyl-38-1,7-diaza-2-indene)-trimethine cyanine.

Examples of azulene dyes include 1.3-bis(guaiazulenyl)propenium, 1.3-bis(6-t-
butyl azulenyl) propenium, 1,5-bis(guaiazulenyl) pentadienium, 1-guaiazulenyl-5-(6'-t-butyl azulenyl) pentadienium, l-guaiazulenyl-5-(6'-octyl azulenyl) pentadienium Examples include nium.

Examples of triarylmethane dyes include crystal violet and malachite green.

Examples of fluoran dyes include rhodamine B and the like.

Examples of triarylamine dyes include tri(p-diethylaminophenyl)aminium.

Examples of the fluorene dye include 36-bis(dimethylamino)-9-(p-dimethylaminophenyl)fluorenium.

Examples of polymethine dyes having an anilino group include 1,3-bis(p-diethylaminophenyl)propenium, 1,1,3.3-tetrakis(p-diethylaminophenyl)propenium, and 1,1,3.3- Tetrakis(p-morpholinophenyl)propenium, 1.3
-bis(p-diethylaminophenyl)-2-methylfrobenilam, 1,2,3-tris(p-diethylaminostyryl)carbonium, 1,3-bis(p-diethylaminophenyl)-1-(p-tolyl) Propenium, 1,1,5.5-tetrakis(p-diethylaminophenyl)pentadienium, 1,1,5,5-tetrakis(p-dipropylaminophenyl)pentadienium, 1,5-bis(p- diethylaminophenyl) -1
,5-diphenylbentadienium, 1,5-bis(
p-dimethylaminophenyl) -1,5-bis(p-
anisyl) bentagenium, 1-[γ-(p-dimethylaminophenyl)propenylidene]-guaiazulenium, 1.1,5.5-tetrakis(p-diethylaminophenyl)-3-methylpentagenium, etc. It will be done.

As shown in the general formula (1), the borate anion that forms a salt with the cations listed above must have at least one cyano group, and the other substituents must be the same. and may be different from each other, and is selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an alicyclic group, an aryl group, an aryloxy group, an aralkyl group, and a heterocyclic group. Further, substituents may be bonded to each other to form a ring compound.

Here, preferred examples of the above alkyl groups include methyl group, ethyl group, propyl group, l-propyl group, butyl group, 5ec-butyl group, t-butyl group, l-
Butyl group, amyl, t-amyl group, n-hexyl group, n
-octyl it-octyl group, etc. can be mentioned.

Examples of the alkenyl group include vinyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, dodecynyl, and prenyl groups.

Examples of the alkynyl group include an acetyl group, propargyl group, butenyl group, pentynyl group, hexynyl group, and heptenyl group.

Examples of the alkoxyalkyl group include methoxyethyl group, ethoxymethyl group, methoxypropyl group, ethoxypropyl group, and ethoxybutyl group.

Examples of the alicyclic group include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and alkyl substituted products thereof.

It is.

Examples of the aryl group include phenyl group, naphthyl group, tolyl group, xylyl group, methoxyphenyl group, dimethoxyphenyl group, trimethoxyphenyl group, ethoxyphenyl group, dimethylaminophenyl group, diethylaminophenyl group, dipropylaminophenyl group, dibenzylaminophenyl group. and diphenylaminophenyl & p-chlorophenyl groups.

Examples of the aryloxy group include a phenoxy group, a naphthoxy group, and a catecholoxy group.

Examples of the aralkyl group include benzyl group, phenethyl group, α-naphthylmethyl group, β-naphthylmethyl group,
p-methoxybenzyl group, furfuryl group, p-chlorobenzyl group, etc., and examples of the heterocyclic group include pyridyl group, quinolyl group, revidyl group, methylbiridyl group, furyl group, thienyl group, indolyl group, virol group, and carbazolyl group. , N-ethylcarbazolyl group, etc.

Further, as specific examples of cyanoborate anions to be combined with the above cations, for example, cyanotriphenylborate, cyanotrianisborate, cyanotrip
-Chlorophenylborate, cyanotritolylborate, cyanotributylborate, cyanotripentylborate, cyanotrihexylborate, cyanotricyclopentylborate, cyanotrip-methoxybenzylborate, cyanotrifurfurylborate, cyanotrimethoxyethylborate, cyanotri2-thienylborate , cyanodiphenylbutylborate, cyanocyanisbutylborate, cyanodi-2-thienylhexylborate, and the like.

The method for synthesizing the cyanoborate salt of the photopolymerization initiator of the present invention will be explained using cyanotriphenylborate as an example. First, triphenylborane and sodium cyanide are heated to about 150°C to obtain a yield of 40-40°C. 60%
Sodium cyanotriphenylborate can be obtained. In addition, by reacting tetramethylammonium tetraphenylborate or trimethylammonium tetraphenylborate with sodium cyanide or potassium cyanide, yields of 40~
There are methods to give sodium cyanotriphenylborate or potassium cyanotriphenylborate at 60%.

(Example 1 Next, the present invention will be explained by examples.

Example 1 <Synthesis of 2-methyl-6-(N-domethoxyphenylaminovinyl)ethylpyridinium triphenylcyanoborate> 2-Methyl-6-(N-p-methoxyphenylaminovinyl)ethylpyridinium under safety light Bromide 2.0
1 part was dissolved in 25 parts of methanol. While stirring the above solution, a dispersion of 1.8 parts of sodium cyanotriphenylborate in methanol 101 was slowly added. After stirring at room temperature for 1 hour, the precipitate was filtered, washed with water, and dried. 2.8 parts of yellow crystals were obtained by the above steps. The maximum absorption wavelength of this material in acetonitrile was 420 r+m.

Example 2 <Synthesis of 1.1,5.5-tetrakis(p-diethylaminophenyl)pentadienium trianiscyanoborate> 1.1,5.5-tetrakis(p-diethylaminophenyl)pentadienium iodide 3 0 part was dissolved in 30 parts of acetic anhydride, and while stirring while shielding from light with aluminum foil, a solution of 1.5 parts of sodium trianiscyanoborate in 15 parts of acetic anhydride was added dropwise under cooling. While further stirring, the temperature was raised to room temperature, the precipitate was filtered, then washed with a small amount of methanol, and dried. 3.4 parts of a blue target product were obtained by performing 0 or more operations.

The maximum absorption wavelength of this target substance in acetonitrile is 82
It was 0 nm.

Example 3 An imaging medium was prepared using the cyanoborate salt obtained in Example 1.

First, a solution having the following composition was prepared.

・Polyvinyl butyral 10 parts ・Dipentaerythritol hexaacrylate 8 parts ・2-Methyl-6-(N-p-methoxyphenylaminovinyl)ethylpyridinium triphenylcyanoborate 1.2 parts ・p-
Ethyl dimethylaminobenzoate 0.8 parts Methyl ethyl ketone 60 parts The above solution was applied to a polyethylene terephthalate (PET) film with a dry film thickness of 6.
It was applied so that -.

On top of that, dry polyvinyl alcohol layer with a thickness of 2 IJTl.
An image forming medium was obtained.

A mask was placed on top of this, and an ultra-high pressure mercury lamp was exposed for 3 seconds from a distance of 60CI11. After the polyvinyl alcohol layer was removed by washing with water, it was etched with an ethanol solution, and the unexposed areas were dissolved, leaving a polymerized image consisting of the exposed areas on the film.

Example 4 First, a solution having the following composition was prepared.

・Polymethyl methacrylate 2 parts ・Chlorinated rubber 6 parts ・Trimethylolpropane triacrylate 10 parts ・2-Methyl-6-(N-p-methoxyphenylaminovinyl)ethylpyridinium tributylcyanoborate 1.2 parts ・p-dimethylamino 1.0 parts of ethyl benzoate and 70 parts of a toluene/methyl ethyl ketone mixture The above solution was applied to a PET film to a dry film thickness of 4 mils.

This was laminated onto a grained aluminum plate to obtain image forming medium A.

A negative mask was superimposed on the image forming medium A obtained, and a 500W
It was exposed for 3 seconds from a distance of 60 cm using an ultra-high pressure mercury lamp. When the PET film was peeled off, the exposed image remained as a clear polymerized image on the aluminum plate.

Separately, the image forming medium A was left in a constant temperature bath at 60°C and 80% RH for 4 days, and imagewise exposed for 3 seconds while changing the exposure distance using the mercury lamp, and the highest resolution of the resulting polymerized image ( Book 10n) was evaluated. For comparison, image forming medium B was prepared in the same manner using triphenylbutylborate as a photopolymerization initiator instead of the cyanoborate salt, and evaluated in the same manner. The results are shown in Table 1.

Table 1 Medium A using the photopolymerization initiator of the present invention is medium B of the comparative example
It can be seen that the sensitivity after aging is superior compared to that of the previous one, and the resolution achieved by Beer Apart is superior.

Example 5 The following composition was added to 100 parts of an aqueous solution of 2.5% by weight of an ethylene-maleic anhydride copolymer, and dispersed using a homomixer to have an average particle size of 3.7 mm.

・Trimethylolpropane triacrylate 60 parts ・Photopolymerization initiator obtained in Example 2 2.2 parts・p
-Ethyl dimethylaminobenzoate], 55 parts 2-
Anilino-6-ethylaminofluorane 5.6 parts/dichloromethane 15.0 parts After stirring this dispersion for 1 hour, 3.5 parts of urea and 5.0 parts of melamine were added, and further 12 parts of formalin were added. 2
After adjusting the pH to 8 with 0% sodium carbonate, the temperature was raised to 60°C and stirring was continued for an additional 4 hours to perform microencapsulation.

20 parts of a 10% by weight PVA solution was added to the microcapsule dispersion thus obtained, and the mixture was coated on an aluminum-deposited PET film and dried to obtain an image forming medium C.

After the medium C was imagewise exposed with a semiconductor laser of 830 nm, it was overlapped with an image receptor coated with a color developer on a PET film, and a nip width of 4 was applied under pressure of 250 kg/cm2.
It was passed between rollers of mm. A clear green image was obtained on the image receptor.

Example 6 An image forming medium was produced in the same manner as in Example 3 except that the borate anion of the photopolymerization initiator was changed from triphenyl cyanoborate to diphenylbutyl cyanoborate. When an image was formed in the same manner as in Example 3, a similarly clear polymerized image was obtained.

[Effects of the Invention] As explained above, the photopolymerization initiator of the present invention has excellent stability over time and photosensitivity, and is effective for image forming media that provide clear images with excellent resolution.

Claims (1)

[Claims] 1. The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) [In the above formula (I), D^■ is a cationic residue, R^1, R
^2 and R^3 are the same or different and are selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an alicyclic group, an aryl group, an aryloxy group, an aralkyl group, and a heterocyclic group. Furthermore, R^1 and R^2 may be combined to form a ring compound.] A photopolymerization initiator represented by the following.