JP3458547B2 - Photopolymerizable composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photopolymerizable composition. In particular, the present invention relates to a photopolymerizable composition containing a photopolymerization initiation system having high sensitivity to light in the visible region and having good dissolution stability.

[0002]

2. Description of the Related Art Conventionally, many image forming methods utilizing a photopolymerization system are known. For example, a photopolymerizable composition comprising a compound containing an addition-polymerizable ethylenic double bond, a photopolymerization initiator, and an organic polymer binder optionally used is prepared, and the photopolymerizable composition is supported. A photosensitive material having a layer of the photopolymerizable composition applied on the body is prepared, and the desired image is imagewise exposed to polymerize and cure the exposed portion, and the unexposed portion is dissolved and removed to form a cured relief image. And a layer of a photopolymerizable composition is provided between two supports in which at least one of the above-mentioned light-sensitive materials is transparent, and the transparent support side is imagewise exposed to cause a change in adhesive strength due to light. After that, there is a method of forming an image by peeling the support, and an image forming method utilizing the change of toner adherability of the photopolymerizable composition layer due to light. Conventionally, benzoin, benzoin alkyl ether, benzyl ketal, benzophenone, anthraquinone, benzyl, or Michler's ketone has been used as the photopolymerization initiator of the photopolymerizable composition applied to these methods.

However, these photopolymerization initiators are
Compared with the ability to initiate photopolymerization for light in the ultraviolet region below 00 nm, it is significantly lower than that for light in the visible light region above 400 nm, thus limiting the range of application of photopolymerizable compositions containing them. In recent years, with the development of image forming technology, there has been a strong demand for photopolymers having a high sensitivity to light rays in the visible region. For example, it is a light-sensitive material suitable for non-contact type projection exposure plate making, laser plate making by visible light laser, and the like. Among these technologies, especially the 488 of argon ion laser
The plate-making method using an oscillation beam of nm is considered to be one of the most promising techniques in the future.

Several proposals have hitherto been made for photopolymerization compositions containing a photopolymerization initiation system capable of being sensitive to light rays in the visible light region. For example, a system of hexaarylbiimidazole and (p-dialkylaminobenzylidene) ketone (JP-A-47-2528, JP-A-54-155).
292, JP-A-56-166154), a system of ketocoumarin and an activator (JP-A-52-112681,
JP-A-58-15503, JP-A-60-88005), a system of a substituted triazine and a sensitizer (JP-A-54-54).
151024, JP-A-58-29803, JP-A-5-
8-40302), biimidazole, styrene derivative, thiol system (JP-A-59-56403), organic peroxide and dye system (JP-A-59-1402).
03, JP-A-59-189340)
A system of a titanocene compound and a sensitizer (JP-A-63-2211).
No. 10, JP-A-4-26154, JP-A-4-2197.
No. 56). Although these are certainly effective to some extent, they still do not have sufficient properties from a practical point of view. In addition to this, as a visible sensitization system using a titanocene compound, for example, a combination system with a coumarin compound having a structure having a specific heterocyclic residue has been proposed, and a certain level of effect is expected (Japanese Patent Application Laid-Open No. Hei 3). -2397
No. 03).

[0005]

However, even in the case of this system, when it is applied to, for example, laser plate making, it has some problems, that is, higher sensitivity and better dissolution stability. The system was required.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have used a photopolymerization initiation system in which a coumarin compound having a specific skeleton and a titanocene compound are combined to produce visible light. , Especially 488 nm
The present invention was found to be a photopolymerizable composition having high sensitivity to the above-mentioned rays, excellent dissolution stability and safelight property, and suitable for laser plate making.

That is, the first object of the present invention is to provide a photopolymerizable composition having sufficient sensitivity, and the second object is to provide a photopolymerizable composition excellent in dissolution stability. Yet another object is to provide a photopolymerizable composition having excellent sensitivity especially at 488 nm and suitable for laser plate making. As a result of intensive studies to solve these problems, the object of the present invention is to provide a compound containing at least one addition-polymerizable ethylenically unsaturated double bond and a photopolymerization initiation system-containing photopolymerization initiation system. In the polymerizable composition, the photopolymerization initiation system is (a) at least one coumarin compound represented by the following general formula [I].

[0008]

[Chemical 3]

(Wherein at least one pair of R ² and R ⁴ and R ¹ and R ³ is linked to represent an alkylene group substituted with a lower alkyl group, and R ² and R ⁴ and R ¹ and R 3 ³
R ¹ and R ² if any one of
Represents an optionally substituted alkyl group, R ³ and R ⁴ each represent a hydrogen atom or an alkyl group, and R ⁵ represents a heterocyclic residue having a total of 3 to 17 carbon atoms. ) And (b) at least one kind of titanocene compound, and a photopolymerizable composition characterized by the above.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The compound having at least one addition-polymerizable ethylenically unsaturated double bond contained as the first essential component in the photopolymerizable composition of the present invention (hereinafter abbreviated as “ethylenic compound”) means photopolymerization. When the photosensitive composition is irradiated with actinic rays, it is a compound having an ethylenically unsaturated double bond that undergoes addition polymerization by the action of a photopolymerization initiation system that is a second essential component and is cured, for example, It is a monomer having the above double bond, or a polymer having an ethylenically unsaturated double bond in the side chain or main chain. Incidentally, the meaning of the monomer in the present invention is a concept corresponding to a so-called polymer substance, and therefore includes not only a narrowly defined monomer but also a dimer, a trimer and an oligomer. .

Examples of the monomer having an ethylenically unsaturated bond include unsaturated carboxylic acid, ester of aliphatic polyhydroxy compound and unsaturated carboxylic acid; ester of aromatic polyhydroxy compound and unsaturated carboxylic acid; Examples thereof include esters obtained by an esterification reaction of a saturated carboxylic acid with a polyvalent carboxylic acid and the above-mentioned aliphatic polyhydroxy compound, polyvalent hydroxy compound such as aromatic polyhydroxy compound, and the like.

The ester of the aliphatic polyhydroxy compound and the unsaturated carboxylic acid is not limited, but specific examples thereof include ethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate. , Pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, acrylate ester of polyhydroxy compound such as glycerol acrylate, Methacrylic acid ester in which acrylate was replaced with methacrylate, similarly replaced with itaconate Itaconic acid esters, maleic acid esters in which instead of the crotonic acid ester or maleate was replaced crotonate.

Examples of the ester of an aromatic polyhydroxy compound and an unsaturated carboxylic acid include hydroquinone diacrylate, hydroquinone dimethacrylate, resorcin diacrylate, resorcin dimethacrylate and pyrogallol triacrylate. The ester obtained by the esterification reaction of an unsaturated carboxylic acid with a polyvalent carboxylic acid or a polyvalent hydroxy compound is not necessarily a single substance, but representative specific examples include acrylic acid, phthalic acid and ethylene glycol. Examples thereof include condensates, condensates of acrylic acid, maleic acid and diethylene glycol, condensates of methacrylic acid, terephthalic acid and pentaerythritol, condensates of acrylic acid, adipic acid, butanediol and glycerin.

In addition to the above ester-based (meth) acrylates, there are so-called urethane-based (meth) acrylates and epoxy-based (meth) acrylates. The former can be prepared by an addition reaction between a polyvalent isocyanate and hydroxyacrylic esters, and the latter can be prepared by an addition reaction between a polyvalent epoxy compound and hydroxyacrylic esters.

Other examples of the ethylenic compound used in the present invention include acrylamides such as ethylenebisacrylamide; allyl esters such as diallyl phthalate;
Vinyl group-containing compounds such as divinyl phthalate are useful. The polymer having an ethylenically unsaturated bond in the main chain described above is, for example, a polyester obtained by a polycondensation reaction of an unsaturated divalent carboxylic acid and a dihydroxy compound,
There are polyamides and the like obtained by polycondensation reaction of unsaturated divalent carboxylic acid and diamine. The polymer having an ethylenically unsaturated bond in the side chain is a condensation polymer of a dicarboxylic acid having an unsaturated bond in the side chain, such as itaconic acid, propylidene succinic acid, ethylidene malonic acid, etc. and a dihydroxy or diamine compound. . Further, a polymer having a functional group having a reactive activity such as a hydroxy group or a methyl halide group in its side chain, for example, polyvinyl alcohol, poly (2-hydroxyethyl methacrylate), polyepichlorohydrin, etc. and acrylic acid, methacrylic acid, crotonic acid, etc. Polymers obtained by the macromolecular reaction with the unsaturated carboxylic acid can also be suitably used.

Among the above-mentioned ethylenic compounds, acrylic acid ester or methacrylic acid ester monomers can be particularly preferably used, and among these, acrylic acid ester or methacrylic acid ester of an aliphatic polyhydroxy compound is preferable. Next, the photopolymerization initiation system, which is the second essential component of the photopolymerization composition of the present invention, will be described. The photopolymerization initiation system of the present invention is composed of a combination of two kinds of components, and the first component thereof is a coumarin compound represented by the above general formula [I] represented as (a) in the present invention.

[0017] In the general formula (I), and at least one pair is connected to R ² and R ⁴ and R ¹ and R ^3, represents an alkylene group substituted with a lower alkyl group, R ² and R
^When any ^{one of 4} and R ¹ and R ³ is not linked, R ¹ and R ² each represent an optionally substituted alkyl group, and R ³ and R ⁴ are each a hydrogen atom or an alkyl group. Represents a group. The alkyl represented by R ¹ and R ² has about 1 to 10 carbon atoms, preferably 2 to
The number of carbon atoms of the alkyl group represented by R ³ and R ⁴ is preferably about 1 to 4. R ⁵ represents a heterocyclic residue having a total of 3 to 17 carbon atoms, and among them, a nitrogen-containing aromatic heterocyclic residue is preferable and the total number of carbon atoms is 3 to 1
The fused ring system nitrogen-containing aromatic ring residue of 1 is preferable. Specific examples thereof include benzothiazolyl, benzoxazolyl, benzimidazolyl and the like.

A compound having a 7-dialkylamino group, particularly a 7-diethylamino group or a julolidyl group in the 7-amino group of the present compound is known or suggested. However, these are not always sufficient in terms of sensitivity and dissolution stability. The dissolution stability described here refers to not only the solvent stability but also the dissolution stability in the solid photosensitive layer. Regarding these problems,
As a result of various studies, we have found that these difficulties can be solved by using the coumarin compound having the structure of the general formula [I]. That is, in the case of an alkylene group in which R ¹ and R ³ and / or R ² and R ⁴ in the general formula [I] are linked and substituted with a lower alkyl group, the above properties are improved. Here, the carbon number of the lower alkyl group is 1 to 2
Is preferred, and the number of carbon atoms in the connecting chain of the alkylene group is about 2 to 4, and 3 is particularly preferred. More preferably, the above properties are remarkably improved when an alkylene group having 3 carbon atoms, particularly a 3,3-dialkyl-1,3-propylene group of a connecting chain substituted with a lower dialkyl group is formed.
In particular, 1 of 3,3-dialkyl-1,3-propylene group
It is preferable that the carbon atom at the position is bonded to the nitrogen atom. Further, the heterocyclic ring at the 3-position is preferably a ring containing a thiazole ring or an oxazole ring.

As a method for introducing the substituent, for example, as described in US Pat. No. 4,736,032, 1-chloro-3, m-aminophenol is added to m-aminophenol.
This is achieved by condensation addition of 3-dialkyl-2-propene. The tetraalkyl-substituted 8-hydroxyjulolidine thus obtained can be easily converted to the compound [I] of the present invention by a conventional method.
For example, it may be prepared by the following route.

[0020]

[Chemical 4]

Typical examples of the compounds represented by the general formula [I] will be given below, but these should be understood as examples until now.

[0022]

[Chemical 5]

[0023]

[Chemical 6]

And the like. Of these, those having a structure in which the amino group at the 7-position is linked by a 1,1-dimethyl-1,3-propylene group are preferable.

Next, the second component (b) the titanocene compound of the photopolymerization initiation system of the present invention will be explained. The titanocene compound is not particularly limited, but is, for example, JP-A-59-
It can be appropriately selected and used from various titanocene compounds described in JP-A-152396, JP-A-61-151197 and the like. More specifically, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5 , 6-Pentafluorophen-1-yl, dicyclopentadienyl-T
i-bis-2,3,5,6-tetrafluorophenyl-1
-Yl, di-cyclopentadienyl-Ti-bis-2,
4,6-Trifluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,6-di-fluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4 -Di-fluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,
6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis- 2,6-difluorophen-1
-Yl, di-cyclopentadienyl-Ti-bis-2,
6-difluoro-3- (pyr-1-yl) -phenyl-1
Examples include titanium complexes having a dicyclopentadienyl group such as -yl (hereinafter abbreviated as B-1).

Specific examples of the two kinds of components (a) and (b) constituting the photopolymerization initiation system of the present invention have been shown above.
The component (a) is 0.1 to 20% by weight, more preferably 0.5 to 15% by weight, and the component (b) is 0.2 to 0% by weight.
-40% by weight, more preferably 1-30% by weight.

In the photopolymerizable composition of the present invention, in addition to the above-mentioned components, an organic polymer substance may be further added as a binder in order to modify the composition and improve the physical properties after photocuring. it can. The binder may be appropriately selected depending on the purpose of improving compatibility, film-forming property, developability, adhesiveness and the like. Specifically, for example, to improve the water-based developability, acrylic acid copolymer, methacrylic acid copolymer, itaconic acid copolymer, partially esterified maleic acid copolymer, acidic cellulose modified product having a carboxyl group in the side chain, Examples include polyethylene oxide and polyvinylpyrrolidone. To improve film strength and adhesion, a polyether of epichlorohydrin and bisphenol A; soluble nylon; alkyl polymethacrylate such as polymethylmethacrylate or alkyl polyacrylate; alkyl methacrylate and acrylonitrile, acrylic acid, methacrylic acid , Copolymers with vinyl chloride, vinylidene chloride, styrene, etc .; copolymers with acrylonitrile and vinyl chloride, vinylidene chloride; vinylidene chloride, chlorinated polyolefins, copolymers with vinyl chloride and vinyl acetate; polyvinyl acetate; Acrylonitrile / styrene copolymer; Acrylonitrile / butadiene / styrene copolymer; Polyvinyl alkyl ether; Polyvinyl alkyl ketone; Polystyrene; Polyamide; Polyurethane; Polyethylene terephthalate isophthalate Mention may be made of acetyl cellulose and polyvinyl butyral. These binders can be added and mixed in a weight ratio of generally 500% or less, preferably 200% or less with respect to the ethylenic compound.

The photopolymerizable composition of the present invention may further contain a thermal polymerization inhibitor, a colorant, a plasticizer, a surface protective agent, a smoothing agent, if necessary.
Coating aids and other additives can be added. Examples of the thermal polymerization inhibitor include hydroquinone, p-methoxyphenol, pyrogallol, catechol, 2,6-di-
There are t-butyl-p-cresol, β-naphthol, and the like. Examples of the colorant include phthalocyanine pigments, azo pigments, carbon black, pigments such as titanium oxide, ethyl violet, crystal violet, azo dyes, anthraquinone dyes. , There are cyanine dyes. When the binder is used, the thermal polymerization inhibitor and the colorant are added in an amount of 0.01 to 5% of the thermal polymerization inhibitor and 0.1% of the colorant with respect to the total weight of the ethylenic compound and the binder. ~ 4
0% is preferable.

Examples of the plasticizer include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerin, etc. When used, 30% or less is generally added to the total weight of the ethylenic compound and the binder.

When using the photopolymerizable composition of the present invention,
The light-sensitive material can be prepared by forming the light-sensitive material without a solvent or dissolving it in a suitable solvent to form a solution, which is coated on a support and dried. Examples of the solvent include methyl ethyl ketone, cyclohexanone, butyl acetate, amyl acetate, methyl lactate, toluene, xylene, monochlorobenzene, carbon tetrachloride, trichloroethylene, trichloroethane, dimethylformamide, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, bentoquinone, propylene glycol methyl ether acetate. Etc., and one kind or two or more kinds can be used in combination.

The support applied when preparing a light-sensitive material using the photopolymerizable composition of the present invention may be any of those usually used. For example, a sheet of metal such as aluminum, magnesium, copper, zinc, chromium, nickel, iron or an alloy containing them as a main component; high-quality paper, art paper,
Papers such as release paper; inorganic sheets such as glass and ceramics; polyethylene terephthalate, polyethylene, polymethylmethacrylate, vinyl chloride, vinyl chloride-vinylidene chloride copolymer, polystyrene, 6-nylon, cellulose triacetate, cellulose acetate butyrate, etc. Polymer sheets, etc.

Further, the photopolymerizable composition of the present invention is further provided with a known technique for preventing adverse effects such as sensitivity decrease and storage stability deterioration due to oxygen, for example, providing a peelable transparent cover sheet on the photosensitive layer. Wax-like substance with low oxygen permeability,
It is also possible to provide a coating layer made of a water-soluble polymer or the like.
The exposure light source applicable to the composition of the present invention is not particularly limited, but carbon arc, high pressure mercury lamp, xenon lamp, metal halide lamp, fluorescent lamp, tungsten lamp, helium cadmium laser, argon ion laser, YAG laser, etc. of 400 nm or more. A general-purpose light source including visible light can be used more suitably.

[0033]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples unless it exceeds the gist. Example 1 2 g of a methyl methacrylate / methacrylic acid copolymer (weight average molecular weight 45,000, polymerization ratio 85/15) and 2 g of trimethylolpropane triacrylate were dissolved in 36 g of methyl ethyl ketone. To this, 80 mg of the photoinitiator component, that is, the component (b), the titanocene compound B-1, was added.
In addition, the coumarin compound A-1 of the component (a) is further added to 80
mg was added and dissolved to obtain a sample photosensitive solution. This is applied to a grained and anodized aluminum sheet using a whirler so as to have a dry film thickness of 2 μm.
A photosensitive material sample was prepared by coating so as to have a thickness of μm.

Next, a xenon lamp; UI-501C manufactured by USHIO INC. Was used as a sample of this light-sensitive material, and a spectral sensitivity measuring device manufactured by Narumi Co., Ltd. was used so that the horizontal axis shows wavelength and the vertical axis shows logarithmically weak light intensity. For 10 seconds. The exposed sample was developed with an aqueous solution containing 6% by weight of butyl cellosolve and 1% by weight of sodium silicate, and the minimum amount of exposure required for photocured image formation was calculated from the height of the cured image corresponding to each wavelength obtained. Then, the sensitivity of each wavelength of the photosensitive composition was used. As a result, the sensitivity corresponding to the wavelength of 488 nm is 65μ.
It was J / cm ² . This sample retained the same sensitivity even after being left at room temperature for 4 months, and the appearance of the photosensitive layer was not particularly abnormal.

Example 2 Instead of the coumarin compound A-1 in Example 1, A-
The same evaluation was performed except that 3 was used. This sample initially showed a sensitivity of 78 μJ / cm ² . It retained its sensitivity even after 4 months at room temperature, and no abnormalities were observed in the appearance of the sample.

Example 3 A-4 was used in place of the coumarin compound A-1 in Example 1.
It evaluated similarly except having used. This sample initially showed 85 μJ / cm ² . It retained its sensitivity even after 4 months at room temperature, and no abnormality was found in the appearance of the sample.

Example 4 Instead of the coumarin compound A-1 in Example 1, A-2 was used.
It evaluated similarly except having used. This sample initially showed 90 μJ / cm ² . It retained its sensitivity even after 4 months at room temperature, and no abnormality was found in the appearance of the sample.

Comparative Example 1 The following R was used in place of the coumarin compound A-1 in Example 1.
It evaluated similarly except having used -1. This sample showed a sensitivity of 100 μJ / cm ² in the initial stage, but after 4 months at room temperature, crystallization precipitation of the coumarin compound R-1 was partially observed, and as a result, the yellow color of the photosensitive layer faded and the sensitivity decreased part. Had occurred.

Comparative Example 2 Evaluation was made in the same manner as in Example 1 except that the following R-2 was used instead of A-1. This sample is 60 μJ /
cm ² was exhibited, but after standing at room temperature for 4 months, crystallization precipitation of R-2 was partially observed, and as a result, the yellow color of the photosensitive layer was discolored and a sensitivity lowering portion was generated.

[0040]

[Chemical 7]

[0041]

The photopolymerizable composition of the present invention has extremely high sensitivity to visible light and is excellent in dissolution stability.
Therefore, the composition is useful in a wide range of application fields, for example, printing plates such as planographic printing, intaglio printing, letterpress printing, photoresists for printed wiring and IC, dry film, images such as relief images and image duplication. It is industrially very useful because it can be used for forming, photocurable ink, paint, adhesive and the like.

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-5-289335 (JP, A) JP-A-6-43642 (JP, A) JP-A-3-239703 (JP, A) JP-A-63- 258903 (JP, A) JP-A-8-29973 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (8)

(57) [Claims] 1. A photopolymerizable composition comprising a compound having at least one ethylenically unsaturated double bond capable of addition polymerization and a photopolymerization initiation system, wherein the photopolymerization initiation system is (a) I] at least one coumarin compound represented by the formula: (Wherein at least one pair of R ² and R ⁴ and R ¹ and R ³ is linked to represent an alkylene group substituted by a lower alkyl group, any of R ² and R ⁴ and R ¹ and R ³ When one pair is not linked, R ¹ and R ² each represent an optionally substituted alkyl group, R ³ and R ⁴ each represent a hydrogen atom or an alkyl group,
R ⁵ represents a heterocyclic residue having a total of 3 to 17 carbon atoms. ) And (b) at least one kind of titanocene compound, and a photopolymerizable composition characterized by the above-mentioned. 2. R in the general formula [I] ² And R ^Four ,
And R ¹ And R ³ Both were substituted with a lower alkyl group
The photopolymerizable compound according to claim 1, wherein the photopolymerizable compounds are linked by an alkylene group.
Composition. 3. An alkylene group in the above general formula [I]
The number of carbon atoms in the connecting chain of 2 to 4 is described in claim 1 or 2.
The photopolymerizable composition described above. 4. An alkylene group in the general formula [I]
The carbon number of the lower alkyl group of the substituent of 1 to 2 is
Item 4. The photopolymerizable composition according to any one of Items 1 to 3. 5. The alkylene group in the general formula [I] is represented by the following formula [II] : The photopolymerizable composition according to any one of claims 1 to 4, which is 6. The 3,3-dimethyl-formula of the formula [II]
The 1-position carbon atom of the 1,3-propylene group is bonded to the nitrogen atom.
The photopolymerizable composition according to claim 5, wherein the photopolymerizable composition is combined. 7. R in the general formula [I] ^Five But Ben
Zothiazolyl, benzoxazolyl, or benzimidazole
The light weight according to any one of claims 1 to 6, which is zolyl.
Compatible composition. 8. An addition-polymerizable ethylenically unsaturated double bond
A compound having at least one compound is an acrylic acid ester
Or a methacrylic acid ester.
The photopolymerizable composition according to any of the above.