JPH0313580B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to photopolymerizable imaging compositions. Conventionally, a composition consisting of a binder made of a polymeric material, a photopolymerizable monomer, a photopolymerization initiator, a photosensitizer, etc. is applied to the surface of a base material, and an image is formed by shining light through a negative image or the like on the surface of the base material. It is known that the image can be developed by polymerizing or crosslinking the areas exposed to light and making them insoluble in solvents, and eluting the areas that are not exposed to light.This principle is used in the production of printing plates and printed wiring boards. It is applied to. It is also known that by adding a photochromic agent such as a leuco dye to the above composition, it is possible to clearly distinguish between areas exposed to light and areas not exposed to light. However, when polymerizing or crosslinking or coloring a composition coated on a substrate using an ultraviolet light source such as a commonly used high-pressure mercury lamp as a light source, the presence of a coloring material reduces the polymerization or crosslinking rate. However, the disadvantage is that the exposure time must be long for this purpose, since the light energy absorbed by the sensitizer, polymerization initiator, etc. in the composition is divided into both color development and polymerization or crosslinking. It is assumed that this is the cause. The present invention solves the above-mentioned drawbacks, and produces color development at the same time as polymerization or crosslinking, which reduces sensitivity and eliminates the need for longer exposure times. The purpose of this invention is to provide an image-forming composition suitable for. That is, the gist of the present invention is (a) a binder made of a polymeric material, (b) a photopolymerization monomer, (c) a photopolymerization initiator, (d) a leuco dye, and (e) a cyan group-substituted coumarin compound, A cyanated aromatic compound selected from the group consisting of a group-substituted naphthalene compound, a cyan group-substituted anthracene compound, a cyan group-substituted tetracene compound, and a cyan group-substituted phenanthrene compound, and whose light absorption wavelength range is different from that of the photopolymerization initiator. The present invention relates to a photopolymerizable image-forming composition characterized by containing a type photoactivator. The binder used in the present invention is made of a polymeric material, and any binder conventionally used as a binder for image forming compositions can be used, such as acetylcellulose, acetylbutylcellulose, polyacrylic Examples include methyl acid, polymethacrylic acid, methacrylic acid-methyl methacrylate copolymer, and halogenated polyolefin. In addition, the photopolymerizable monomer in the present invention refers to a monomer that is activated by light irradiation and starts polymerization in the presence of a photopolymerization initiator.
Monomers having a boiling point of 100°C or higher at normal pressure and having at least one ethylene terminal group are preferably used, specifically pentaerythritol triacrylate, polyethylene glycol diacrylate, etc. , triethylene glycol diacrylate, polyethylene glycol dimethacrylate, polyethylene diacrylate, polymethylene dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, and other polyacrylate or polymethacrylate monomers, and oligomerization of these monomers. Those that have been prepared are preferably used. Furthermore, as the photopolymerization initiator used in the present invention, conventionally known photopolymerization initiators are widely used, and phenylkent-based photopolymerization initiators are particularly preferably used. Specific examples of the polymerization initiator include benzophenone, P-aminophenyl ketone such as P,P'-bis(dimethylamino)benzophenone (hereinafter referred to as Michler's ketone), benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin propyl ether. , benzoin isoprolpiether, benzyl anthraquinone, 2-methyl-anthraquinone, 2-ethyl-anthraquinone, 2-
Tertiary butyl anthraquinone, 2-amino anthraquinone, etc., and many of these,
It is used as a polymerization initiator by absorbing light energy with long wavelengths in the range of about 320 to 370 nm. And these polymerization initiators are 2
A mixture of benzophenone and Michler's ketone may be used in combination, and it is particularly preferable to use a mixture of benzophenone and Michler's ketone, since the efficiency of polymerization initiation by irradiation light is excellent and the exposure time is further shortened. Further, in the present invention, a combination of a leuco dye and a cyanated aromatic compound type photoactivator having a light absorption wavelength range different from that of the photopolymerization initiator is used as a coloring agent. That is, the leuco dye in the present invention refers to a colorless or light-colored dye obtained by reducing a colored compound, and which develops color when oxidized by a cyanide aromatic compound type photoactivator described below, and most of them contain amino groups. It belongs to the leuco compound of substituted triarylmethane dyes, but is not limited thereto. Specific examples of such leuco dyes include leuco crystal violet, tris(4-diethylamino-
triaminotriphenylmethane such as O-tolyl)methane, leucomalachite green, bis(4-
diethylamino-O-tolyl) phenylmethane,
Bis(4-diethylamino-O-tolyl)(3,
4-dimethoxyphenyl)methane, bis(4-diethylamino-O-tolyl)(P-benzylthiophenyl)methane, bis(P-diethylamino-
O-tolyl)(P-α-methoxyacetamidophenyl)methane, and the like. These leuco dyes may be made into a salt by reacting with an acid, and examples of the acid at this time include mineral acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, and phosphoric acid, acetic acid, oxalic acid, and phosphoric acid. -trienesulfonic acid,
Examples include organic acids such as trichloroacetic acid, and narrowly defined Lewis acids that do not contain hydrogen, such as zinc chloride, zinc bromide, ferric chloride, and boron trifluoride. In the present invention, the cyanated aromatic compound type photoactivator having a light absorption wavelength range different from that of the photopolymerization initiator includes a cyanide group-substituted coumarin compound, a cyanide group-substituted naphthalene compound, a cyanide group-substituted anthracene compound, and a cyanide group-substituted anthracene compound. It is a compound selected from the group consisting of group-substituted tetracene compounds and cyan group-substituted phenanthrene compounds, and mainly has a wavelength of 300 nm.
It has the effect of oxidizing the above-mentioned leuco dye and developing color when activated by irradiation with active light in the wavelength range of ~600 nm. Specific examples include 3-benzothiazoyl-4-cyano-7-diethylaminocoumarin and compounds whose structural formulas are represented by the following (1) to (4).

【formula】

【formula】

【formula】

Cyan group-substituted coumarin dyes such as [Formula]; cyan group-substituted naphthalenes such as α-cyanonaphthalene and β-cyanonaphthalene; 9-cyanoanthracene, 9,10-
Cyan group-substituted anthracenes such as dicyanoanthracene; 1-cyanotetracene, 9-cyanophenanthrene, etc., and particularly preferred examples include cyanocoumarin dyes. These photoactivators are selected from among the photopolymerization initiators that have a light absorption wavelength range different from that of the initiator to be actually used, and the light absorption wavelengths of both are selected and used. Generally, the difference in wavelength is required to be about 20 nm or more, which is the difference in wavelength showing the highest peak of the absorption spectrum. However, if the distribution of the absorption spectra of the photoactivator and the polymerization initiator are both narrow, the difference in peak wavelength may be 10 nm, but if the distribution is wide, for example, a difference of 50 nm or more is required. Considering the wavelength and distribution of the peak of the spectrum, it is assumed that the light of the wavelength mainly used by the polymerization initiator activates the photoactivator and is also used to develop the color of the leuco dye, thereby substantially curing the polymerization of the composition. Those having a difference in wavelength range that does not cause any interference are appropriately selected. To prepare the composition of the present invention, the binder, photopolymerizable monomer, photoinitiator, leuco dye, and photoactivator may be added and mixed uniformly. Because it is used by forming a thin layer on the surface of a substrate made of the material, it has a viscosity that allows it to be mixed with methyl elethyl ketone or other appropriate solvent and applied to the substrate, etc. Preferably, the composition is a liquid composition that can be dried. In addition, the quantitative relationship of the above components is as follows: 10 to 300 parts by weight of a photopolymerizable monomer, 0.1 to 20 parts by weight of a photopolymerization initiator, and leuco dye to 100 parts by weight of a binder made of a polymeric material.
It is preferred to use 0.01 to 10 parts by weight, more preferably 0.1 to 4 parts by weight and 0.001 to 10 parts by weight, more preferably 0.01 to 0.1 parts by weight of the photoactivator. The composition of the present invention can be used for making relief printing plates and photoresists. Usually, a solution of the composition of the present invention dissolved in a solvent is coated on a transparent sheet-like support and dried. A coating layer is formed on the object, and this is laminated on the surface of the object on which an image such as a photoresist image is to be formed by heat fusion, and active light is irradiated from above through a negative or the like to expose the exposed areas. After that, if a transparent sheet remains, it is peeled off, the unexposed areas are removed with a solvent, etc., an image is formed, and then etching is performed as necessary. In the composition of the present invention, the leuco dye activated by the cyanated aromatic compound type photoactivator contained therein is used as a coloring agent to color the exposed area, so that the exposed area is colored during the exposure process. It is easy to distinguish between exposed areas and non-exposed areas, which is very convenient when performing multiple exposures or checking the exposure status.Furthermore, unlike the spiropyran compounds used in the past, the colored image disappears within a short time after exposure. The durability of the colored image is excellent and the workability is improved without causing any damage. Furthermore, when leuco dye-based color formers have been used in the past, the energy of the irradiated light is split into both polymerization of the composition and color development, which slows down the polymerization curing speed and reduces sensitivity. In contrast, the composition of the present invention does not have such drawbacks and requires only a short exposure time, resulting in excellent photosensitivity. The present invention will be explained below based on examples. Synthesis example 3-benzothiazoyl-7- which is a condensate of P-miN'diethylaminosalicyaldehyde and 2-cyanomethylbenzothiazole
When 0.1 mol of diethylaminocoumarin was dissolved in 500 ml of dimethylformamide at room temperature and an excess amount of 30% aqueous sodium cyanide was added and stirred, a transparent brown solution was immediately obtained. This was cooled to 8-10°C, bromine was directly added dropwise, and the resulting precipitate was filtered and dried to obtain 0.9 mol of 3-benzothiazoyl-4cyano-7-diethylaminocoumarin. This was a red crystal with a maximum optical absorption spectrum at 519 nm. Example 1 Polymethyl methacrylate 60g Trimethylolpropane triacrylate 33g Benzophenone (λmax 330nm) 3.5g Michler's ketone (λmax 370nm) 1.5g Leuco crystal violet 1.0g 3-Benzothiazoyl-4-cyano-7-diethylaminocoumarin (λmax ^* 520nm) 0.1g *λmax represents the wavelength of the highest peak of the optical absorption spectrum. same as below. A pale red solution of the above compound dissolved in methyl ethyl ketone to a total amount of 950 g was placed on a polyethylene terephthalate film support to give a dry thickness of 950 g.
The coating was applied to a thickness of 50 μm, and after drying, it was laminated at a temperature of 115° C. on an epoxy-glass fiber board coated with copper so that the coating was in contact with the copper surface. Next, apply the photosensitive laminate prepared above to 400W.
At a distance of 1 m from a high-pressure mercury lamp, 90 millijoules/cm2 (mJ/ cm ² ) exposure was performed. It was hot for 20 seconds during this time. After exposure, peel off the film support and remove the exposed layer.
It was developed by dipping in 1,1,1-trichloroethane for 40 seconds and dried. In the test negative image, the 9-step image board remained, and the resolution in the printed wiring image was 50μ. In addition, before the development, the red color in the unexposed area is
In the exposed area of the printed circuit, a purple color clearly appeared (color absorbance 0.5), and the contrast of the different colors was clear, making it extremely convenient for exposure inspection. The printed circuit board after exposure was left overnight, developed and etched the next day, and the film was removed to form a printed circuit, but the color development in the exposed area was well maintained until the film was removed. Example 2 0.01 g of 9,10-dicyanoanthracene (λmax 400 nm) was used in place of 0.1 g of 3-benzothiazoyl-4-cyano-7-diethylaminocoumarin used in Example 1 as a photoactivator. Except for this, development was performed using the test negative image and a printed wiring circuit was created in the same manner as in Example 1. The results showed that the degree of curing of the exposed area, resolution, degree of color development, and color persistence were all the same as in Example 1. Example 3 Polymethyl methacrylate 60g Trimethylolpropane acrylate 33g Benzophenone (λmax 330nm) 3.5g Michler's ketone (λmax 370nm) 1.5g Leucomalachite green 1.0g 9-cyanophenanthrene 0.02g The above compounds were dissolved in methyl ethyl ketone to make a total amount of 300g. The resulting solution was applied to a polyethylene terephthalate film support to a dry thickness of 25μ, and the film was dried. A photosensitive laminate was prepared in the same manner as in Example 1. In the same manner, a test negative image was developed and a printed wiring circuit was created. As a result, the degree of hardening of the exposed area was the same as in Example 1, and the resolution of the printed wiring image was 40μ.
It was hot. Furthermore, before the development, the exposed area was colorless, and the exposed area of the printed circuit had a clear green color, and the degree of color development (absorbance 0.5) and the persistence of color development were as good as in Example 1. Examples 1 to 5 Photosensitive laminates were prepared in the same manner as in Example 1 using the materials shown in the respective columns of Comparative Examples 1 to 5 in Table 1, and exposed in the same manner as in Example 1. and development. The results were as shown in Table 1. Regarding the resolution, Comparative Example 1 has a resolution of approximately 200 μ;
Comparative Examples 2 and 3 were even worse.

【table】

Claims (1)

[Scope of Claims] 1 (a) a binder made of a polymeric material, (b) a highly photopolymerizable monomer, (c) a highly photopolymerized initiator, (d) a leuco dye, and (e) a cyan group-substituted coumarin compound. , a cyanide aromatic aromatic whose light absorption wavelength range is different from that of the photopolymerization initiator, which is selected from the group consisting of a cyan group-substituted naphthalene compound, a cyan group-substituted anthracene compound, a cyan group-substituted tetracene compound, and a cyan group-substituted phenanthrene compound. 1. A photopolymerizable image-forming composition comprising a group compound type photoactivator. 2. The composition according to item 1, wherein the leuco dye is an amino group-substituted triarylmethane dye.