JPH0352853B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photosensitive resin composition. More specifically, the present invention relates to a photosensitive resin composition that is cured by irradiation with actinic rays and has color forming properties. Free radical-based photosensitive resins are well known as photosensitive resins that harden and develop color upon irradiation with actinic rays. That is,
When light is irradiated on a mixed system of a polymer compound in which an aromatic amine unsubstituted at the para-position is suspended on the polymer side chain via nitrogen and a multihalogen compound that can generate radicals by the action of light, triphenylmethane-based It is characterized in that a crosslinking reaction between polymers occurs at the same time as the dye is generated. For examples of this resin and its curing/coloring mechanism, please refer to "Basic and Applied Photopolymers" (P162-164) published by CMC Co., Ltd. on September 5, 1970, or April 26, 1980.
It is described in "New Photosensitive Resin" (written by Takahiro Tsunoda), published by the Printing Society Publishing Department (P150-153). The present inventors were conducting research on a series of photosensitive resins using amine compounds containing aromatic rings as starting materials in order to develop acid-developable photosensitive resins. It was discovered that a photosensitive resin having a chemical structure represented by the following formula develops color upon curing when exposed to light using a sensitizer system, or that color develops when treated with an acid after exposure and curing, and as a result of extensive studies, the present invention was developed. It was completed. That is, the present invention relates to a color-forming photosensitive resin composition characterized by containing the following A and B as main components. A A photosensitive group that can react with actinic ray irradiation in the molecule A photosensitive resin with a chemical structure represented by: B A sensitizer system capable of causing a reaction in the above A by irradiation with actinic rays. In the above photosensitive resin composition, when the sensitizer system contains a halogen compound that can generate halogen radicals when irradiated with actinic rays, the generated halogen radicals extract hydrogen and generate acid. Therefore, it hardens and develops color at the same time as it is exposed to light. Also, diazonium hexafluoride phosphorus salts that produce Lewis acids develop color and harden upon exposure. In the case of the above-mentioned photosensitive resin composition made of a sensitizer system that does not contain such a halogen compound, it develops color by being cured by exposure and then being treated with an acid. The fact that the photosensitive resin of the present invention is different from conventionally well-known free radical type photosensitive resins in its curing and coloring mechanism is explained as follows. First, in conventional free radical photosensitive resins, the curing mechanism is based on the halogenated methyl group present in the sensitizer and the amino group of the aromatic ring present in the resin, as explained in the above-mentioned literature. On the other hand, the carbon at the para position reacts with the photodissociation of the halogen, and curing progresses. That is, it is explained that the following crosslinked structure is obtained. It is also explained that the color development mechanism is based on the triphenylmethane structure generated as the curing progresses. In other words, in order for conventional halogen free radical photosensitive resins to photocure and develop color, it is necessary to combine the unsubstituted amino aromatic ring at the para position to generate the triphenylmethane structure and the halogenated methyl group that serves as the reaction center. Its existence is considered essential. In contrast, the photosensitive resin of the present invention is one in which, for example, (meth)acrylic groups, allyl groups, epoxy groups, etc. undergo a polymerization reaction and are cured by irradiation with light in the presence of a photoinitiator. The mechanism is completely different. In addition, when we investigated the coloring mechanism in detail, we found that
As a phenomenology, it was recognized that there is the following coloring discipline. That is, it is thought that in resin A having a diaminodiphenylmethane structure, hydrogen is extracted by the hydrogen abstraction type sensitizer excited by UV light, and a stable diaminodiphenylmethane radical structure is formed. This is state B, and no color develops. When this B state is treated with acid, it develops a bright color. At this time, the presence of halogen is not necessary, and color can be developed by nitric acid, phosphoric acid, sulfuric acid, etc. in addition to hydrochloric acid. This state is BH ⁺ . It is thought that when BH ⁺ is treated with an alkali, the color disappears and returns to B. On the other hand, when resin A is exposed to UV light in the presence of a hydrogen abstraction type sensitizer and a polyhalogen, an acid is generated by the exposure, so that it becomes BH ⁺ and develops color at the same time as the exposure. The photosensitive resin composition of the present invention does not necessarily require a halogenated methyl group and an unsubstituted amino aromatic ring at the para position, which are considered essential for photocuring and color development of conventional halogen free radical photosensitive resins. It's not something. In the photosensitive resin composition of the present invention, the polyhalogen compound generates protons and contributes to coloring the resin. Although the polyhalogen compound also functions as a photocuring accelerator, it is not an essential compound. In the photosensitive resin composition of the present invention, photocuring of the resin occurs even when a photoradical generator containing no halogen atoms is used. In this case, since no protons are supplied, color does not develop at the same time as light irradiation, but if a separate acid treatment is performed, protons are supplied and color develops. From the above explanation, it is clear that the photosensitive resin composition of the present invention is a novel color-forming photosensitive resin different from conventional halogen free radical photosensitive resins. Next, each component of the present invention will be explained in detail. There is no particular restriction as long as it can cause a reaction when the resin of component A is irradiated, but acrylic or methacrylic groups are particularly preferred from the viewpoint of resin synthesis, ease of handling, and photosensitive properties. It will be done. A typical resin structure of the photosensitive resin according to the present invention is as follows, but the photosensitive group may be replaced with another photosensitive group such as an allyl group or an epoxy group. (R here represents, for example, H or _CH3 .) This type of resin compound is synthesized by reacting 1 mole of 4,4'-diaminodiphenylmethane with 4 moles of glycidyl (meth)acrylate. Substantially the same product can also be obtained by reacting 1 mole of N,N,N',N'-tetraglycidyldiaminodiphenylmethane with 4 moles of (meth)acrylic acid. (Here, R is H or CH ₃ , and R' is a reactive residue of aldehyde.) Depending on the selection of aldehyde, different color tones can be produced. The structure of the photosensitive group and resin is not limited to these, and a sensitizing group etc. may be introduced into the existing hydroxyl group. Modified chain extension with oligomer 4,
4'diaminodiphenylmethane resins can also be used. The sensitizer system of component B may be any sensitizer system as long as it can cause a reaction of the photosensitive group of the photosensitive resin of the present invention upon irradiation with actinic rays, but preferably thioxanthone, benzoin, anthraquinone, benzophenone. A system containing one or more sensitizers selected from the following is preferable. Note that when the photosensitive group is an acrylic group or a methacrylic group, thioxanthone is particularly preferable. The halogen compound capable of generating halogen radicals is not limited, but it is preferable to use at least one halogen compound selected from the group of compounds represented by the following structural formula.

【formula】

【formula】

【formula】

【formula】

[Formula] CX ₄ (where X is halogen, R is H or a hydrocarbon residue having 1 to 5 carbon atoms, m is an integer of 1, 2, or 3, and n is 3-m. ) Specifically, alkyl chloroacetate, alkyl dichloroacetate, alkyl trichloroacetate, alkyl bromoacetate,
Dibromate alkyl ester, tribromoacetate alkyl ester, 4-chloromethylbenzophenone, trichloromethylphenylsulfone, tribromomethylphenylsulfone, trichloracetophenone, tribromoacetophenone, α,α-
Examples include dichloro-4-phenoxyacetophenone, tetrachloromethane, and tetrabromomethane. When an epoxy group is used as a photosensitive group, the following diazo salts can also be used in addition to polyhalogen compounds. for example

【formula】

【formula】

[Formula] [R=H, CH ₃ −, C ₂ H ₅ −, R'-O- (R' is an alkyl group), -NO ² ,
(CH ₃ ) ₂ N−,

【formula】

【formula】

[Formula]] etc. The amount of the sensitizer system to be blended is 1 to 20 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight of the photosensitive resin. In addition, if a halogen compound is added, the appropriate amount can be selected, but usually the total amount of the sensitizer is
40-60% is used. The color-forming photosensitive resin composition according to the present invention has the above-mentioned A and B as main components, but also contains other solvents, reactive diluents, dyes, pigments, adhesion modifiers, dispersants, and thermal polymerization inhibitors. Agents and the like may be appropriately added as necessary. Mixing of these components can be performed by conventionally known methods. The thus obtained photosensitive resin composition of the present invention is characterized in that it is cured by irradiation with actinic rays and also develops color in the presence of an acid. In a system that does not contain a polyhalogen compound, color is developed by acid treatment after exposure, but surprisingly, the color development function by acid treatment is retained even after being left for one day or more after exposure. In addition, it has reversible coloring property in that after coloring by acid treatment, the color fades when treated with alkali, and then color develops when treated with acid again. Furthermore, when used as a photoresist resin, development with an acidic aqueous solution is also possible in addition to development with an organic solvent, and the cured product thereof has excellent alkali resistance. Possible uses of the resin of the present invention that take advantage of these characteristics include photoresist resins and recording materials. It is particularly useful for applications to printing plate materials and color recording papers that require multiple exposures. Others, ink,
It can also be used in paints and coatings. Next, the present invention will be explained in more detail with reference to synthesis examples and examples, but these are not limited to the examples in any way. Note that parts and % in the examples indicate parts by weight and % by weight. Synthesis Example 1 19.8 parts of 4,4'-diaminodiphenylmethane, 56.8 parts of glycidyl methacrylate, and 40 parts of N,N-dimethylformamide were placed in a reaction flask equipped with a stirrer, thermometer, condenser, dropping device, and nitrogen inlet tube. was charged and gradually heated under a nitrogen atmosphere with stirring, and the reaction was carried out at 115°C to 125°C for 3 hours. After cooling the resulting reaction solution, it was gradually poured into 1,000 parts of a 1% aqueous sulfuric acid solution while stirring.
After continuing stirring for about 30 minutes, neutralization was performed using 5% sodium hydroxide to obtain a resin precipitate. After thoroughly washing this precipitate with water, it is dissolved in 300 parts of acetone containing 0.05 part of hydroquinone. Next, the solution was gradually poured into 1000 parts of water while stirring, the resin was sufficiently precipitated, and then separated.
After further natural drying, the dried resin was thoroughly dissolved in 500 parts of dioxane to obtain a photosensitive resin solution (S-1) with a concentration of about 10%. Synthesis Example 2 Using an apparatus similar to Synthesis Example 1, 19.8 parts of 4,4'-diaminodiphenylmethane, 42.6 parts of glycidyl methacrylate, and 30 parts of N,N-dimethylformamide were heated at 115°C with stirring under a nitrogen atmosphere.
After reacting at 125°C for 3 hours, the reaction solution was cooled, 300 parts of dioxane was added, and 72.7 parts of trichloroacetic acid chloride was gradually added dropwise with stirring from a dropping device. The reaction was carried out for 8 hours. Next, the obtained reaction solution was poured into 2000 parts of water with stirring, and then a 5% aqueous sodium hydroxide solution was gradually added to precipitate the resin, and in order to sufficiently precipitate the resin, 100 parts of saturated sulfuric acid was added. Aqueous sodium solution was added. Next, the precipitated resin was separated, thoroughly washed with water, dissolved in 400 parts of acetone and dioxane (1:1) mixed solvent, and this solution was poured into water again with stirring, and the precipitated resin After air drying, the dried resin was dissolved using a predetermined amount of dioxane to obtain a photosensitive resin solution (S-2) with a concentration of about 10%. Synthesis Example 3 Using a reaction apparatus similar to Synthesis Example 1, 19.8 parts of 4,4'-diaminodiphenylmethane, 14.9 parts of P-dimethylaminobenzaldehyde, 30 parts of N,N-dimethylformamide, and 10 parts of dioxane were added into a reaction flask. while stirring under nitrogen atmosphere.
After refluxing at 90°C to 100°C for 1 hour, 28 parts of glycidyl methacrylate was added and the reaction was carried out at 115°C to 125°C for 2.5 hours. Next, the resulting reaction solution was cooled, and then gradually poured into 1000 parts of water with stirring, continued stirring for about 30 minutes, and then left to stand, precipitated, and separated to obtain a resin. This obtained resin was dissolved in 100 parts of acetone, and this solution was poured into 1000 parts of water again.
A resin was obtained by the same treatment as above, and after further natural drying, it was dissolved in 300 parts of acetone and dioxane (1:1) mixed solvent, and a photosensitive resin solution (S-3) with a concentration of about 10% was prepared. ) was obtained. Example 1 10 of the (S-1) photosensitive resin obtained in Synthesis Example 1
% dioxane solution and 0.5 part of the polyhalogen compound shown in Table 1 were thoroughly mixed and dissolved to prepare a photosensitive solution. These photosensitive solutions were applied to a grained aluminum plate, dried with warm air (80℃ x 20 to 30 minutes),
(film thickness 1-2μ), chemical lamp (irradiation intensity
The colors shown in Table 1 were clearly developed by vacuum contact exposure at 1.05 mj/cm ² ·sec). A further color increasing effect was observed in the photosensitive solution prepared by adding 0.5 part of 2,4-diisopropylthioxanthone (hereinafter referred to as DITX) to the above photosensitive solution. These results are shown in Table 1 together with the results of the number of remaining steps when developed with 1% hydrochloric acid.

[Table] Example 2 10 of the (S-1) photosensitive resin obtained in Synthesis Example 1
% solution: 100 parts DITX 0.5 part N,N-dimethylaminobenzoic acid isoamyl ester 0.5 parts were thoroughly mixed to prepare a photosensitive solution. When the sample was coated and dried in the same manner as in Example 1 and irradiated with a chemical lamp, no color developed, but when the test piece was immersed in 1% hydrochloric acid, a beautiful blue color developed. Further, when the exposed test piece was left for 2 days and then immersed in 1% hydrochloric acid, the same color developed clearly. The cured coating was extremely hard, with a pencil hardness of 4H or higher, adhered well to the aluminum substrate, and showed good alkali resistance. Also, when the test piece was immersed in 1% nitric acid, sulfuric acid, or phosphoric acid instead of 1% hydrochloric acid, the color developed similarly. Example 3 10 of the (S-2) photosensitive resin obtained in Synthesis Example 2
% solution 100 parts Dimethylanthraquinone 0.5 parts Tribromomethyl phenyl sulfone 0.5 parts A photosensitive solution was prepared in the same manner as in Example 1, coated, dried and exposed. It developed a beautiful blue color when exposed to light.
The number of remaining stages of the step tablet developed with 1% HCl was 9, and the minimum curing light amount was 3.5 mj/cm ² .
The cured coating film adhered tightly and had good alkali resistance. Example 4 10 of the (S-3) photosensitive resin obtained in Synthesis Example 3
% solution 100 parts DITX 1 part α,α'-dichloro-4-phenoxyacetophenone 1 part A photosensitive solution prepared by thoroughly mixing and dissolving the above three components was applied onto a grained polyester film.
After drying, a test piece of the photosensitive resin coating was prepared. A negative mask was closely attached to this test piece, and when it was irradiated with a chemical lamp, it was colored and cured, and when it was developed with 1% hydrochloric acid, a green colored resin image was obtained. At this time, the coloring sensitivity (minimum amount of coloring light) measured from the number of remaining steps was 10.5 mj/cm ² and the photocuring sensitivity was 31.5 mj/cm ² . Example 5 (S-3) 10% solution of photosensitive resin 100 parts Carbon tetrabromide 2 parts A photosensitive solution prepared by blending the above two components was applied to a grained polyester film and dried to form a photosensitive resin coating. A test piece was prepared. A step tablet negative mask was closely attached to this test piece, and the test piece was exposed to light using a chemical lamp and developed with 1% hydrochloric acid to obtain a dark green colored resin image. The color sensitivity at this time is
5.3 mj/cm ² Photocuring sensitivity was 63 mj/cm ² Example 6 N,N,N',N'-tetraglycidyldiaminodiphenylmethane 10 parts Dioxane 90 parts Carbon tetrabromide 1 part The above three components A photosensitive solution was prepared by thoroughly mixing and dissolving. This photosensitive solution was applied to a grained aluminum plate and dried to prepare a test piece of photosensitive resin coating with a thickness of approximately 2 μm. When a negative mask was placed on this and exposed to light with a chemical lamp, it developed a blue color and hardened. 1%
A resin image can be obtained by developing with hydrochloric acid.
The coloring sensitivity of this product is 10.1mj/cm ² , light curing sensitivity,
It was 63mj/ ^cm2 . Example 7 A test piece of a photosensitive resin coating was prepared in the same manner as in Example 6, except that 4-methoxydiphenylamine 4'-diazonium phosphorus hexafluoride salt was used in place of carbon tetrabromide. When this material was irradiated with a chemical lamp, it developed a blue color and hardened. It was also possible to develop with 1% hydrochloric acid. The color development sensitivity measured by step tablet is 10.0 mj/cm ² , and the light curing sensitivity is
It was 63mj/ ^cm2 .

Claims (1)

[Scope of Claims] 1. A color-forming photosensitive resin composition comprising the following A and B as main components. A A photosensitive group that can react with actinic ray irradiation in the molecule A photosensitive resin B having a chemical structure represented by: A sensitizer system 2 that can cause a reaction when the above A is irradiated with actinic rays; A sensitizer system that can induce a reaction when irradiated with actinic rays; The photosensitive resin composition according to claim 1, which contains a halogen compound capable of generating . 3. The photosensitive resin composition according to claim 1, wherein the photosensitive group in component A is an acrylic group or a methacryl group.