JPS5857729B2 - Kankousei Sosabutsu - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photosensitive composition characterized by using a ketosulfoxide compound as a photopolymerization catalyst.

The photopolymerization catalyst uses light energy, mainly 200 mμ to 50 mμ.
It is used when coexisting unsaturated compounds are polymerized by light irradiation with a wavelength of 0 mμ.

Various types of photopolymerization catalysts are known.

Thiacilloin ether type benzoin ethyl ether, benzoin isopropyl ether, polynuclear quinone type anthraquinone, 2-methylanthraquinone, benzophenone, orthobenzoylbenzoic acid methyl ester, diacetyl, dibenzyltriphenylphosphine, azo type azobisisobutylene. These include lonitrile, phenylazovaleronitrile, and the like.

In recent years, the use of photopolymerization catalysts on an industrial scale has been variously studied and put into practical use in connection with pollution-free efforts.

Although many types of photopolymerization catalysts exist, none of them fully satisfies the photocuring activity, storage stability, and colorability.

Good photocuring activity means that the ability to initiate polymerization upon irradiation with light is good, and excellent storage stability means that the photosensitive composition has little oral deterioration in the dark. Good colorability means that there is no coloration in the cured resin when it is photocured by adding a photopolymerization catalyst.

The present inventor focused on the fact that phenacylphenyl sulfoxide does not color photocurable compositions, conducted research on ketosulfoxide compounds that have good photocurable performance, and completed the present invention. .

That is, the present invention relates to the formula (R1 represents an alkyl group, a phenyl group, or a substituted phenyl group, and R2 and R3 represent hydrogen, an alkyl group, or an alkoxyl group).

However, R2 and R3 do not represent hydrogen at the same time.

This is a photosensitive composition characterized by using a ketosulfoxide compound represented by ) as a photopolymerization catalyst.

Conventionally, for example, when benzine isopropyl ether is added to transparent unsaturated polyester and cured by light irradiation, the polymer becomes yellow as the photocuring progresses, and compared with conventional heat-cured products, the product value is lower. It did not receive high praise.

A photocurable composition prepared by adding phenacylphenyl sulfoxide is not colored and is a very preferable photopolymerization catalyst from the viewpoint of colorability.

However, when compared with a general-purpose photopolymerization catalyst such as benzoin ethyl ether, it was clearly inferior in terms of photocuring performance.

The present inventors estimated that the photodecomposition mechanism of ketosulfoxides is based on the following.

Then, an electron-donating group, such as an alkyl group or an alkoxyl group, is added to the substituent in (I), and in (I), a substituent that is advantageous for synthesis is selected to the extent that it does not impair the stability of the radical. .

By adding these photopolymerization catalysts to a photocurable resin and irradiating the resin with light, a desired resin in terms of photocurability and colorability was obtained.

In the present invention, the ketosulfoxide compounds include, for example, phenacyl p-)'Jrusulfoxide, p-
Methoxy, phenyl phenacyl sulfoxide, acetonyl p-tolyl sulfoxide, etc.

Ketosulfoxide compounds are produced by reacting an α-halogen ketone such as α-chloroacetophenone or monochloroacetone with the corresponding sodium salt of a mercaptan to obtain a ketosulfide, and then reacting in acetone or acetic acid. It can be synthesized in good yield by oxidation with 30% hydrogen peroxide or by other known oxidation methods.

During photocuring, the ketosulfoxide photopolymerization catalyst of the present invention is 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the total composition of the photocurable resin, crosslinkable monomer, etc. They can be used alone or as a mixture of two or more, or in combination with other known or general-purpose photopolymerization catalysts.

As the photocurable resin used in the present invention, any resin used in conventional photosensitive compositions may be used.

For example, unsaturated polyester resins, acrylic resins and alkyd resins into which polymerizable unsaturated groups have been introduced, adducts of diisocyanate compounds and vinyl monomers having hydroxyl groups, and multi-vinyl compounds added by urethanization reactions with compounds having hydroxyl groups. , multi-vinyl compounds in which a vinyl monomer having a carboxyl group is added to a compound having two or more epoxy groups through an esterification reaction, and these resins and compounds having photocurable unsaturated groups can be used alone or Can be used as any mixture.

Further, as the crosslinking monomer that can be used in the present invention, any of those used in conventional photosensitive compositions may be used.

For example, styrene, vinyltoluene, dichlorostyrene,
Vinyl acetate, acrylic acid, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, ethyl methacrylate, butyl methacrylate,
lauryl methacrylate, diethylene glycol methacrylate, diallyl terephthalate, diallyl isophthalate, triethylene glycol dimethacrylate, diallyl ether, triallyl in cyanure-I.
Examples include glycidyl methacrylate, divinyl ether, divinylbenzene, vinylpyrrolidone, vinylpyridine, triallyl phosphate, diallylbenzene sulfonate, and the like, which can be used alone or in a suitable mixture.

Furthermore, the photosensitive composition of the present invention may contain additives, fillers, and colorants as necessary.

The light irradiation source necessary for photocuring the photosensitive rough material obtained by the present invention may be one that emits light with a wavelength of 200 to 500 mμ.

Examples of such light sources include sunlight, low-pressure mercury lamps, medium-pressure mercury fireballs, high-pressure mercury lamps, ultra-high-pressure mercury lamps, fluorescent lamps, xenon lamps, tungsten lamps, and the like.

The photosensitive composition obtained according to the present invention is such that the composition cured by light irradiation at an appropriate dose is free of coloration, and furthermore, the photocuring performance is that phenacylphenyl sulfoxide is used as a photopolymerization catalyst. We have now provided a photosensitive composition that is much more expensive than when used as a photosensitive composition and is industrially viable.

In particular, in fields where colorless colorability is required, such as photocurable three-dimensional decorative panels made by adding a photopolymerization catalyst to the areas that should become convex parts, this property is fully demonstrated and he is a newcomer who is contributing to this field. Dew.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples.

Production of resin (1) 81 parts of fumaric acid, 44-5 parts of phthalic anhydride, 31 parts of ethylene glycol, 54 parts of butane-1,3-diol
An unsaturated polyester resin is formed by condensing the 50% by conventional method, diluted with styrene so that the resin content becomes 60%, and the resulting resin solution has a melting point of 50 to 60%. 0.1% paraffin at °C was added.

The resin solution thus obtained is referred to as "Resin A".

★★(2
) 40 parts of ethyl acrylate, 64 parts of butyl acrylate,
104 parts of styrene, 13 parts of 2-hydroxyethyl methacrylate, 2-hydroxyethyl methacrylate in acrylic resin
50 parts of urethane-modified acrylic resin obtained by reacting hydroxyethyl with 43.5 parts of 2,4-tolylene diincyanate adduct were dissolved in 2.5 parts of ethyl acrylate,
Obtain an unsaturated acrylic resin solution.

The resin solution thus obtained is referred to as "Resin B".

Example 1 The ketosulfoxide-based photopolymerization catalyst of the present invention was added in an amount of 2% by weight with respect to resin AI, mixed, and these photosensitive compositions were formed into a coating film with a thickness of 200μ on a glass plate. From a distance of 20C1n, a fluorescent lamp (manufactured by Toshiba, FL-
The time required for the hardness to reach a pencil hardness of 6H or more when irradiated with light (20 BL, 20 Watts, 2 lamps) and the coloring property when continuously irradiated with light for 1 hour are shown in Table 1.

As a comparative example, the results obtained when benzoin ethyl ether and phenacylphenyl sulfoxide were added are shown.

Example 2 The ketosulfoxide-based photopolymerization catalyst of the present invention and benzoin ethyl ether were added and mixed to "Resin B" in various proportions, and these photosensitive compositions were spread on a glass plate to a thickness of 200 μm. As a coating film, this coating film is irradiated with light from a fluorescent lamp (manufactured by Toshiba, FL-20BL, 20 Watts, 2 lamps) from a distance of 20 CrrL, and the hardness reaches a pencil hardness of 6H or more, and continuously for 1 hour. The coloring property when irradiated with light is shown in Table-■.

As a comparative example, a case where benzoin ethyl ether alone was added is shown.

Claims (1)

[Claims] Formula 1 (R1 represents an alkyl group or a phenyl group, R2 is a7
・'Indicates a kill group or an alkoxy group. A photosensitive composition characterized by using a ketosulfoxide compound represented by ) as a photopolymerization catalyst.