JPH0365540B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photocurable image forming composition useful for purposes such as printed wiring, planographic printing, letterpress printing or offset printing. Conventionally, many compositions have been known for such uses, and a typical composition is a combination of a polymer compound and a photopolymerizable monomer. However, a common problem in both cases is that the polymerization of the photopolymerizable monomer is inhibited by the presence of air, especially oxygen, which tends to cause problems such as a decrease in the polymerization rate and insufficient hardness of the cured film. It is. Such curing inhibition may occur, for example, during the production of photoresist plates, when the resist image is attacked by corrosive agents during etching of the base material, making it difficult to form precise images, and during the production of photorelief plates, the image area may be worn away. This may cause problems such as making it impossible to print easily and clearly.
This is something that must be solved for practical use. Yet another problem is that it takes a long time to clean and remove the photocured image area, so it is necessary to shorten this time in order to improve the plate-making efficiency. However, as a result of extensive research, the present inventors found that (A) (a) ethylenically unsaturated carboxylic acid and the general formula [X
(-CH=CH)- ₂ Y (X, Y are carboxyl groups,
Indicates an alkyl group or an aryl group, and does not include cases where X and Y are the same. )], (b) an unsaturated polyester resin containing a polybasic acid and (c) a polyhydric alcohol, and (B) a photopolymerizable unsaturated monomer. The image-forming composition comprising (C) a photopolymerization initiator has good air-drying properties, and is easily photocured even in the presence of oxygen, giving an image of sufficient hardness. If it is necessary to wash or remove the cured image area, it can be easily eluted in an extremely short time by washing the area with an alkaline aqueous solution, which is a novel technology that can significantly improve plate-making efficiency. After discovering this fact, we have completed the present invention. As mentioned above, the present invention is characterized in that an unsaturated polyester resin containing an adduct of an ethylenically unsaturated carboxylic acid and the chain diene compound is used, and in particular, an ethylenically unsaturated dicarboxylic acid and a carboxyl group-containing When an adduct with a diene compound is used, its effect is significantly exhibited.
When using the above adduct, air drying properties and alkali solubility are greatly improved due to the presence of free carboxyl groups and cycloalkene rings formed by Diels-Alder reaction in the unsaturated polyester resin. It will be done. Even if the amount of free carboxyl groups introduced is increased by, for example, introducing a large amount of polybasic acid, the air-drying properties will be lowered, and an image with sufficient hardness will not be obtained, although alkaline solubility will be imparted. Further, when only a cycloalkene ring is introduced, although air drying properties are exhibited, alkali solubility is not sufficient. Examples of polybasic acids which are components of the unsaturated polyester resin of the present invention include maleic anhydride, fumaric acid,
Examples include itaconic acid, tetrahydrophthalic anhydride, phthalic anhydride, isophthalic acid, terphthalic acid, adipic acid, sebacic acid, and trimellitic acid. Polyhydric alcohols include ethylene glycol, propylene glycol, glycerin, diglycerin, 1,3-butylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, polyethylene glycol,
Examples include polypropylene glycol, trimethylolethane, trimethylolpropane, and pentaerythritol. Furthermore, carboxylic acids in the adduct of ethylenically unsaturated carboxylic acid and chain diene compound include maleic anhydride, maleic acid, fumaric acid, O
-carboxycinnamic acid, itaconic acid, glutaconic acid, citraconic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid,
Examples include dicarboxylic acids such as tetrahydroterephthalic acid, benzalactic acid, benzalmalonic acid, and citraconic acid (anhydride), and monocarboxylic acids such as crotonic acid. On the other hand, as the chain diene compound, a diene containing a carboxyl group in the molecule is useful. Representative examples include sorbic acid and cinnamylidene acetic acid. Among the above, adducts of ethylenically unsaturated dicarboxylic acids and carboxyl group-containing diene compounds are preferably used, particularly Diels-Alder reaction adducts of maleic anhydride and sorbic acid, i.e., 6-
Methylcyclohexane-1,2,3 tricarboxylic acid is most useful. The above adducts are added to the unsaturated polyester resin.
Preferably, it is present in a proportion of 2.5 to 50 mol%.
The adduct may be present either at the end of the molecule or within the molecular chain. By further introducing a polyhydric alcohol allyl ether component into the unsaturated polyester resin of the present invention, a higher degree of air-drying property can be exhibited, so its use is advantageous. Examples of allyl ethers of polyhydric alcohols include mono- or diallyl ethers such as glycerin, trimethylolpropane, and trimethylolethane, mono-, di- or triallyl ethers of pentaerythritol, allyl glycidyl ether, allyloxydicyclopentadiene, and phenol-formaldehyde. In addition to partially allyl etherified products of the initial condensate, there may also be mentioned partially allyl etherified products of the initial condensate of urea or melamine and formaldehyde. In addition to the above-mentioned modifiers in preparing the unsaturated polyester resin, oils such as tung oil, linseed oil, dehydrated castor oil, soybean oil, fatty acids thereof, or polyhydric alcohol fatty acid esters may be appropriately used. Unsaturated polyester resins are prepared by any method. For example, by condensing a polybasic acid, a polyhydric alcohol, an ethylenically unsaturated carboxylic acid, and, if necessary, a modifier, according to a conventional method, the double bonds of the ethylenically unsaturated carboxylic acid in the obtained prepolymer are A method of subjecting a chain diene compound to a Diels-Alder reaction, in which an ethylenically unsaturated carboxylic acid and a chain diene compound are reacted in advance to prepare an additive, and this is reacted with a polybasic acid, a polyhydric alcohol, and as necessary. A method of condensing with a modifying agent or the like is carried out depending on the method. The resulting unsaturated polyester resin is a viscous liquid or solid. The molecular weight of the resin is not particularly limited, but it usually has an average molecular weight of 300 to 5000, and an acid value (KOH,
mg/g) of 50 to 400, preferably 100 to 300. If the acid value is less than 50, it is difficult to obtain sufficient alkaline cleaning properties, while if it is more than 400, it is easily affected by the chemicals used in the etching solution, making it impossible to obtain a clear image or causing noticeable stickiness in the image area. Next, the photopolymerizable unsaturated monomer used in the present invention is not particularly limited, and any compound capable of radical polymerization can be used. Suitable monomers are ethylenically unsaturated monomers (vinyl monomers) and compounds containing functional groups such as hydroxyl groups or carboxyl groups. Examples of functional groups include epoxy groups in addition to those mentioned above. Of course, ethylenically unsaturated monomers that do not contain functional groups can also be used, and these are used to impart elasticity to the image forming film or adjust hardness, rather than utilizing their photopolymerizable properties. It is used as an auxiliary agent in combination with ethylenically unsaturated monomers containing functional groups. The compounds will be specifically explained below, but the present invention is not limited thereto. Monomers containing hydroxyl groups include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 1,4-butylene glycol monoacrylate, pentaerythritol mono-, di-, or triacrylate, ethylene glycol monoalrylate, diethylene glycol monoacrylate. , propylene glycol monoacrylate, dipropylene glycol monoacrylate, mono- or diacrylate of glycerin, N-
Examples include methylol acrylamide and N-methylol methacrylamide. In addition, as a monomer containing a carboxyl group, the general formula (meth)acryloyl group-containing polybasic acid ester represented by (here, R, a, A, are the same as above, b
is an integer of 1 to 3, b+c is an integer of 2 to 4, and R' represents an alkylene group, a phenylene group, a carboxyl group-substituted phenylene group, or the like. ). The ester is obtained by a partial esterification reaction between hydroxy (meth)acrylate and a polybasic acid. The compound includes phthalic acid mono(2-acryloxyethyl) ester. Succinic acid mono(2-acryloxyethyl) ester maleic acid mono(2-acryloxyethyl) ester, Hexahydrophthalic acid mono(3-acryloxyethyl ester) Tetrahydrophthalic acid mono(2-acryloxyethyl) ester Mono(2-acryloxyethyl) trimellitate
ester Methyltetrahydrotrimellitic acid mono(2-acryloxyethyl) ester Mono(2-acryloxyethyl) pyromellitic acid
ester and various esters in which the above acryloyl group is substituted with a methacryloyl group. Other usable monomers include glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, 1-vinyl-3,4-epoxycyclohexane, trimethylolpropane triacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,4- Examples include butylene glycol diacrylate, 1,6-hexene glycol diacrylate, N-vinylpyrrolidone, styrene, methyl methacrylate, tetrahydrofuran acrylate, butoxy acrylate, cyclohexyl acrylate, phenoxyethyl acrylate, isobonnell acrylate, and the like. In the present invention, it is advantageous to use the various monomers described above, particularly the (meth)acryloxy group-containing polybasic acid partial ester, in combination with the phosphoric acid monomers described below. That is, when the composition of the present invention is used as a resist ink for printed wiring, the combination of monomers allows the ink to exhibit good adhesion to substrates such as copper plates, and the alkaline cleaning after image formation is much shorter. This is because it is done effectively and on time.
The mixing ratio of the phosphoric acid monomer and the polymerizable monomer is preferably 5/100 to 50/100. Specific examples include phosphoric acid monomers. First, the general formula (meth)acryloxy group-containing phosphate ester represented by (where R: hydrogen or methyl group, A: alkylene group or hydroxyl-substituted alkylene group,
a; an integer of 1 to 3; b; an integer of 1 to 3). The ester is hydroxyalkyl (meth)
It is obtained by the reaction of acrylate with phosphoryl chloride, phosphorus pentoxide, orthophosphoric acid, etc. The compound includes phosphoric acid mono(2-acryloxyethyl) ester Phosphoric acid di(2-acryloxyethyl) ester Phosphoric acid mono(2-methacryloxyethyl) ester etc. Other examples include tri(2-acryloxyethyl) phosphate and tri(2-methacryloxyethyl) phosphate. Examples of photopolymerization initiators include benzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether, dibutyl sulfide, benzyl sulfide,
Organic sulfur compounds such as decyl phenyl sulfide, diazonium salts, tetrazonium salts, complex salts of these with zinc chloride, or condensates thereof, dyes such as azobisisobutyronitrile and methylene blue, or their combination with p-toluenesulfonate ions, etc. combination with, organic peroxide, hydrogen peroxide, pyrylium salt or thiapyrylium salt, acetophenone, benzophenone, benzyl, phenanthrene, thioxanthone, dichloropropylphenyl ketone, anthraquinone, 2-chloroanthraquinone, 2-bromoanthraquinone, anthraquinone β - Sodium sulfonate, 1,5-dinitroanthraquinone, 1,2-penzanthraquinone, phenanthrenequinone, 5-benzoylacenaphthene, 5-nitroacenaphthene, 1,4-naphthoquinone, 18-phthaloylnaphthalene, Examples include 2-nitrofluorene, p-nitroaniline, and biclamide, which may be used alone or in combination of two or more. Not limited to those listed above,
Anything that promotes photopolymerization can be used. Among these, benzoin alkyl ether gives particularly good results in terms of price and sensitivity. In the composition of the present invention, the photopolymerizable unsaturated monomer is 20 to 500% relative to the unsaturated polyester resin.
It is used in proportions of % by weight. Further, the photopolymerization initiator is mixed and used in a range of 1 to 10% by weight based on the resin. Since the photopolymerizable unsaturated monomer also serves as a solvent, the composition can be applied to the substrate as it is, but if necessary, organic solvents such as volatile saturated fatty acid esters, ketones, aromatic hydrocarbons, etc. For example, it can be used after being diluted with ethyl acetate, methyl ethyl ketone, toluene, or xylene. Further, auxiliary agents such as dyes, pigments, and thermal polymerization inhibitors can be used in combination as required. When forming an image using the composition,
When the composition is applied to a base material such as a zinc plate, aluminum plate, copper plate, steel plate, etc. and irradiated with ultraviolet rays through a negative image, only the exposed areas will be cured. It is preferable to form an image on the substrate by a printing method and then irradiate the image with ultraviolet rays to cure it. The former is suitable for producing resist plates and relief plates, and the latter is suitable for purposes such as printed wiring. It can also be used to fill holes in through-hole type printed wiring boards. For resist plates and printed wiring, etc., the base material obtained as described above is etched, the exposed metal parts are corroded, and the remaining photosensitive areas are removed by alkaline cleaning. Used as is. For alkaline cleaning, sodium hydroxide, potassium hydroxide,
Alkali such as sodium carbonate and potassium carbonate
It is used as an aqueous solution of about 0.1 to 5%. Any method such as a spray method or a dipping method can be used for the cleaning operation. Practically speaking, the alkali contact time is 5 seconds to 20 seconds, and the contact temperature is approximately 25 to 50°C. Note that the base material is not limited to the metal plate mentioned above, but also cotton, rayon, wool, polyester, etc.
An image is formed on the surface of a woven or nonwoven fabric made of synthetic fibers such as polyamide, polyvinyl alcohol, or polyacrylonitrile through a screen, then cured by irradiation with ultraviolet rays, and dyed as appropriate to create a pattern on the fabric. It is also possible.
In addition, paper, synthetic resin sheets, etc. may be used as the base material. As a light source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc lamp, a xenon lamp, etc. are used. Hereinafter, the composition of the present invention will be explained in more detail by giving examples. Example 1 97.9 parts of phthalic anhydride, 109.8 parts of isophthalic acid,
172.9 parts of maleic anhydride, ethylene glycol
99.6 parts of propylene glycol and 122.1 parts of propylene glycol were condensed in a nitrogen atmosphere at 220℃ for 4 hours to determine the acid value.
A prepolymer containing 48 [KOHmg/g] was obtained. Next, this prepolymer was cooled to 100°C, 197.7 parts of sorbic acid was added, and the reaction was carried out at 150°C for 1.5 hours to prepare a liquid unsaturated polyester resin having an acid value of 166 [KOHmg/g]. To 100 parts of this resin, 30 parts of 2-hydroxypropyl acrylate, 15 parts of di(2-acryloxyethyl) phosphate, 40 parts of barium sulfate, 3 parts of Aerosil, 0.5 parts of phthalocyanine blue, and Irgakiure 651 (manufactured by Ciba Geigy, Mix 2 parts of acetophenone photopolymerization initiator) and thoroughly mix with a three-roll roll to obtain a viscosity of 15500CP (B-type viscometer, 60 rpm,
An image forming composition (measured at 20°C) was obtained. Next, use this composition to form an image on the copper foil of a printed circuit board using a screen printing method, and immediately
Irradiation was performed for 1 second using a UV lamp with an output of 80 W/cm. The hardness of the image coating film was 2H on a pencil hardness, and the adhesion to the substrate was 100/100, indicating good adhesion. Next, this sample was etched with an aqueous ferric chloride solution at 40°C for 30 minutes. The image showed sufficient chemical resistance. Furthermore, when a 3% aqueous sodium hydroxide solution at 40°C was sprayed, the image area was dissolved after 8 seconds, showing excellent alkali cleaning properties and a precise image of a printed wiring circuit was obtained. Control Example 1 The same experiment as in Example 1 was conducted except that unsaturated polyester was used, omitting the use of sorbic acid. The hardness of the image coating was F. Also, some difficulties were observed in chemical resistance. Control Example 2 The same experiment as in Example 1 was conducted except that an unsaturated polyester resin was used, omitting the use of maleic anhydride. Alkaline cleaning required a long time of 40 seconds. Examples 2 to 7 Example 1 was carried out using the composition shown in Table 1 (only the unsaturated polyester resin and polymerizable monomer were changed).
An image was formed according to . The results are shown in Table 1.

[Table]

Claims (1)

[Claims] 1 (A) (a) Ethylenically unsaturated carboxylic acid and the general formula [X(-CH=CH) _-2Y (where X and Y represent a carboxyl group, an alkyl group, or an aryl group, X and Y
does not include cases where are the same. )], (b) unsaturated polyester resin containing polybasic acid and (c) polyhydric alcohol, (B) photopolymerizable unsaturated monomer (C) a photopolymerization initiator. 2. The image-forming composition according to claim 1, wherein the adduct of the ethylenically unsaturated carboxylic acid and the diene compound is a cycloalkene containing at least two carboxyl groups in the molecule. 3. 6-Methylcyclohexane, an adduct of an ethylenically unsaturated carboxylic acid and a diene compound obtained by the addition reaction of maleic anhydride and sorbic acid.
The image forming composition according to claim 2, which is a 1,2,3 tricarboxylic acid. 4 (A) (A) Ethylenically unsaturated carboxylic acid and the general formula [X(-CH=CH) _-2Y (where X and Y represent a carboxyl group, an alkyl group, or an aryl group, and X and Y
does not include cases where are the same. )], (b) a polybasic acid, (c) a polyhydric alcohol, and (c) an unsaturated polyester resin whose constituent components are polyhydric alcohol allyl ether; ( An image-forming composition comprising B) a photopolymerizable unsaturated monomer and (C) a photopolymerization initiator.