JPH02292307A - Photocurable resin composition - Google Patents

Abstract

PURPOSE:To obtain a photocurable resin composition which is free from an unpleasant odor and lowly viscous by mixing a specified polymerizable photopolymerization initiator with a radical-polymerizable substance. CONSTITUTION:4-(2-Hydroxyethoxy)phenyl-2-(2-hydroxy)propyl ketone of formula I is reacted with a monoisocyanate having at least one (meth)acryloyl group in the molecule of formula II or III (wherein R is H or CH3) at room temperature to 80 deg.C to obtain a polymerizable photopolymerization initiator (A) comprising an acetophenone having at least one (meth)acryloyl group in the molecule. 0.1 to 30wt.% component A is mixed with a radical-polymerizable substance (B) (e.g. unsaturated polyester).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a photocurable resin composition having a satin-containing composition, which is easily crosslinked and cured by irradiation with light, and the cured coating film is odorless.

Traditionally known photocurable resin compositions include unsaturated polyester resins that are crosslinked curable substances, polyester polyacrylates, epoxy polyacrylates,
Polyvalent acrylates such as urethane polyacrylate and polyol polyacrylate are used as photopolymerization initiators, such as benzoin ethers such as penzoin inglobil ether, penzyl ketals such as benzyl dimethyl ketal, acetophenone derivatives such as diethoxyacetophenone, etc. Combinations of chotons and amines, such as the combination of penzophenone and N-methyldiethanolamine, are known.

These photocurable resin compositions can be cured by irradiating the source.
The yt polymerization initiator generates silica radicals and quickly crosslinks and cures. However, these curable compositions have the disadvantage that they emit an unpleasant odor even if the original irradiation is sufficient and the curing is complete. It has been revealed that the cause of this is the volatilization of excess unreacted photopolymerization initiator remaining in the cured product without participating in the photopolymerization reaction. In fact, when the pulverized material of these cured coatings is placed in an extraction container and extracted with an extraction solvent such as tetrahydrofuran, unreacted materials of 50 to 80% of the photopolymerization initiator blended into the curable composition are removed. known to be detected.

Considering the above-mentioned current situation, the present inventors introduced the polymerizable ethylenically unsaturated base photopolymerization initiator into the polymerizable ethylenically unsaturated base photopolymerization initiator. As a result of examining photocurable resin compositions using such novel initiators based on the judgment that no odor is generated, we found that the following (a) and (b) as photopolymerization initiators were used as photopolymerization initiators.
), we have found that a photocurable resin composition in which an acetophenone conductor obtained by reacting two components is combined with a photopolymerization initiator and a crosslinking curable compound becomes a cured composition without unpleasant odor.

First, the present inventors used the following (a) t as a photopolymerization initiator.
(b) # (C) A photocurable resin composition characterized by using an acetophenone derivative having at least one acryloyl group or methachlor group in the molecule, which is obtained by reacting all five components. Japanese Patent Publication No. 63-57038
It is proposed as a number. Although this composition also achieves the odorless characteristic that is the objective of the present invention, this initiator is solid at room temperature, making it inconvenient to handle, and the viscosity of the photocurable resin composition is high. There was a drawback.

Q CH3 (22 Components (3) Component Polyincyanate Compound having at least one hydroxyl group and at least one 7-acryloyl group or methachloro group in one molecule) Therefore, as a result of various studies, we found a specific incyanate compound. By combining component (a) with component (a), it is possible to obtain a photopolymerization initiator whose composition has a low viscosity and does not have the unpleasant odor of a cured composition.

Problems to be Solved by the Invention> An object of the present invention is to provide a photopolymerization initiator whose compounded composition has a low viscosity and does not have the unpleasant odor of a cured composition.

Means for Solving All Problems> The gist of the present invention is to use at least one acryloyl compound in the molecule, which is obtained by reacting the following two components (a) and (k) as a photopolymerization initiator. A photocurable resin composition comprising an acetophenone derivative having a group or a methachlor group and a radically polymerizable compound.

O CR5 Round component Monoincyanate having one acryloyl group or methacrylic group in the molecule Component (a), which is the raw material of the polymerizable acetophenone derivative used in the present invention, 4-(2-hydroxyethoxy-7-enyl-2) -(2-Hydroxy-)probylketone is commercially available from Merck & Co., West Germany under the trade name Darocure 2959, and can be used as is.
9 is a photopolymerization initiator phenyl 2-hydroxy-2, which is also commercially available from Merck & Co. as Cidalocure 1173.
-Like probilketo/, it is an initiator with excellent photopolymerization initiation efficiency and very little yellowing, but photocurable resin compositions using these still have odor from unreacted initiator in the composition even after curing. do.

As the component (b), it is necessary to use an incyanate having at least one acryloyl group or methacryl group in the molecule, as represented by the following structural formula (+), (phantom), for example.

CH2= C-C-0-CH2CH2-NCO ・
...[1]R (R is -1H or 10H5)
When obtaining the polymerizable photopolymerization initiator used in the present invention using two components (IL) and (b), the ratio of each component is such that the number of moles of component (a) ≤ the number of moles of component (1). preferable.

This is to eliminate substantially free ←) components in the reaction product.

The catalyst used in the reaction may be a tin-based catalyst such as diptyltin lacrylate, which is used in general urethane reactions.

This reaction can be carried out without a bath medium or, if necessary, in a solvent or monomer inert to incyanate.

The reaction proceeds rapidly under the above conditions at a temperature from room temperature to about 60 to 80C.

The resin component used in the present invention may be any radically polymerizable compound, but preferred resin components include unsaturated polyester, polyol polyacrylate, polyester polyacrylate, epoxy polyacrylate, and urethane polyacrylate. Acrylate, polyacrylic polyacrylate, melamine polyacrylate, polysiloxane polyacrylate, polyamide polyacrylate can be used.

These may be used alone or in combination of two or more. Furthermore, monomers copolymerizable with these resins can also be used, and specific examples thereof include methyl acrylate, ethyl acrylate, probyl acrylate, n-butyl acrylate, and t6 acrylate.
rt-butyl, acrylic #Rn-hexyl, acrylic relative 2-ethylhexyl, acrylic eRn-nonyl, cyclohexyl acrylate, bezyl acrylate, dicyclobentenyl acrylate, 2-dicyclopentenone ethyl acrylate, Methoxyethyl acrylate, ethoxyethyl acrylate, ethyl acrylate, methoxyethoxyethyl acrylate, ethoxyethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 2-hydroxyglobyl acrylate, 4-hydroxybutyl acrylate, and these methacrylic acid monomer, N-vinyl 2
- Virolitone, N-vinylimidazole, N-vinylcaprolactam, styrene, a-methylstyrene, vinyltoluene, vinyl acetate, propylene. Examples include vinyl ionate and vinyl benzoate.

(9) The composition K of the present invention can be used in combination with a thermoplastic resin within a range that does not impair photocurability. Specific examples include nitrocellulose, acetylcellulose, acetylbutylcellulose, ethylcellulose, cellulose derivatives such as methylcellulose, vinyl chloride, vinylidene chloride, vinyl acetate, polyvinyl alcohol, polyvinyl ether, acrylic resin, styrene resin, polyamide, and fluororesin. , thermoplastic resins such as petroleum resins, alkyd resins,
Examples include processed resins such as rosin ester, rubber derivatives such as chlorinated rubber, and cyclized rubber.

The amount of the polymerizable acetophenone derivative used in the photocurable resin composition of the present invention is in the range of 0.1 to 30% by weight, preferably 1 to 203 ki%.

The photopolymerization initiator used in the photocurable resin composition of the present invention is
Although it is a polymerizable acetophinone derivative, a general photopolymerization initiator can also be used in combination within a range that does not impair the reduction of unpleasant odor, which is the objective of the present invention. Specific examples include penzophenone, bensoin methyl ether, bensoin ethyl ether, bensoin ethyl ether,
Penzoin inglobil ether, benzoyl benzoic acid, benzoyl benzoic acid methane, penzyl dimethyl ketal, 5-3/-dimethyA-4-methoxybenzophenone, 1-(4-dodecylphenyl)-2- Hydroxy-2
-Methylpropan-1-one, 1-hydroxycyclodhexyl phenyl ketone, 2-hydroxy-2-methyl-
1-7enylpropan-1-one, 1-(4-4nogrovir 7enyl)-2-and droxy-2-methylouropan-1-one, methylk7enylcryoxylate, ethyl phenylglyoxylate, 2-methyl-1-
(4-(methylthio)phenyl]-2-morpholinoprobanone-1, tetra(1-butylperoxycarbonyl)penzophenone, 2-chlorotheoxysanthone, 2.
4-diethylthioxanthone, 2,4-diingrovirthioxanthone, 2,4-dimethylthioxanthone, 4
-penzoyl-41-methyldiphenyl sulfide,
Examples include 2,2-diethoxyacetophenone, 2,2-dibutoxyacetophenone, and diethoxyphenylacetophenone.

The photocurable composition of the present invention contains a polymerization inhibitor such as noihydroquinone, p-
Penzoquinone, monohydroquinone monomethyl ether,
p-tert-butylcatechol, monotar
t-butylhytroquinone, α-naphthol, birogallol, etc., and various other additives, such as leveling agents, slip agents, antifoaming agents, anti-sagging agents, anti-cissing agents, wetting agents, pardoning agents, anti-settling agents. etc. can also be used.

Dyes and pigments commonly used for the purpose of coloring the composition of the present invention can also be used.

After adjusting the viscosity of the photocurable composition of the present invention,
One or more inert volatile organic stimulants can be used. Examples include acetate esters such as methyl acetate, ethyl acetate, inglovir acetate, provyl acetate, butyl acetate, amyl acetate, keto/based baths such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diimptyl ketone, cyclohexyl t/ agent, hexene, cyclohexane,
Included are hydrocarbon agents such as toluene and xylene, alcoholic solvents such as ethanol, gropanol, inglobanol, butanol, and imbutanol, and solvents such as cellosolve, selonlube acetate, and butylselonlube.

The photocurable composition of the present invention can be produced simply by uniformly mixing all of the following components as described above. Mixing is generally carried out at room temperature, but may be heated if necessary.

The composition of the present invention is useful for α materials and inks, but it can also be used for casting and molding, and exhibits its effects.

The composition of the present invention can be cured using a low-pressure mercury lamp, medium pressure, or the like in air or nitrogen. Ultraviolet rays may be irradiated from a mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a sequinon lamp, a gallium lamp, a metal halide lamp, a carbon arc lamp, a solar source, or the like.

The present invention will be explained in more detail in the following examples.

Example 1 2-incyanate ethyl methacrylate 155.15
g (1 mol), and 0.9 g (1 mol) of dibutyltin lacrylate as a catalyst.
0 5 7. 9, ygHQiG, 6 as a polymerization initiator
．． 9e Weigh it into a flask, stir, then add 4-(2-
Hydroxy)7enyl-2-(2-hydroxy)probylketone 224.26Ji' (1.0 mol) was added dropwise and the reaction was continued at 60C until the NCO reaction rate reached 98% or higher. After completing the steps, the desired polymerizable photopolymerization initiator A was obtained. This reaction product is a liquid at room temperature.

Next, non-yellowing urethane acrylate, Diabeam ax
-+s055 (manufactured by Mitsubishi Rayon Co., Ltd.) 60 parts by weight and 40 parts by weight of tetraethylene glycol diacrylate,
As a photopolymerization initiator, a polymerizable photopolymerization initiator A O. 0
Two moles of each were mixed together to obtain a photocurable composition shown in Table 1.

Example 2 201.26 J (1 mol) of m-{/7'robenyl-α,a dimethylbenzyl incyanate, 0.064.9 J (1 mol) of dibutyltin laurate as a catalyst, and MEHQiO. 45, Weighed it into an Fe flask, stirred it, and added 4-(2-hydroxy)phenyl-2-(2-
Hydroxy) propyl ketone 224.2d# (1.0 mol) was added dropwise and the reaction was continued at 60C until the Neo reaction rate was 9.
The reaction was terminated when the value reached 896 or more, and the desired polymerizable photopolymerization initiator Byk was obtained. This reaction product is a liquid at room temperature.

Next, non-yellowing urethane acrylate, Diamond Beam Ux
, -6035 (manufactured by Mitsubishi Rayon Co., Ltd.) and 40 parts by weight of tetraethylene glycol diacrylate as a photopolymerization initiator. A photocurable composition shown in Table 1 was obtained.

Comparative Example 1 4-(2-hydroxyethoxy)phenyl-2-(2-
Hydroxy) probyl ketone 2249 (1 mol) and inphorone diincyanate 2 2 6 &( 1.0 2
7) and diptertin lacrylate as a catalyst. o 7
1 K flask was weighed and reacted at 70C for 4 hours with stirring, and 2-hydroxyethyl acrylate 12
2# (1.05 mol), 0 MKHQ as a polymerization inhibitor
．． 6&'i was added dropwise and the reaction was terminated when the Neo reaction rate reached 98% or more, and the desired polymerizable photopolymerization initiator Cf. Nine points. This reaction product is a solid at room temperature.

Next, non-yellowing urethane acrylate Diamond Beam UK
-6035 (manufactured by Mitsubishi Rayon Co., Ltd.) and 40 parts by weight of tetraethylene glycol diacrylate, and a polymerizable photoinitiator C D. A photocurable composition shown in Table 1 was obtained by mixing 0.02 mol.

Comparative Example 2 The photopolymerization initiator in Example 1 was replaced with (-)phenyl 2-(
2-hydroxy)propylkaton 0.0 2 mol, (b
) 4-(2-hydroxyethoxy)phenyl-
2-(2-hydroxy)probylgato 70.02 mol,
(0) Bennoinpropyl ether 0.02 mol, (
') 1-Hydroxycyclohexyl phenyl ketone 0.
The photocurable compositions shown in Table 1 were obtained in the same manner as in Example 1 except that 0.02 mol was used.

Evaluation method: The composition was applied to a white acrylic plate for 5 minutes to form a coating film of 20 lIm, and was heated under a high-pressure mercury lamp with an intensity of 80 W/(to) for 2 hours.
Ultraviolet rays were irradiated at a distance of 0-, and the time required for curing, odor after complete curing, and physical properties of the coating film were summarized in Table 1.

In addition, the composition is applied to a degreased glass plate to form a coating film of 40 μm, and after being completely cured under the same conditions as above, the proportion of unreacted initiator present in the cured coating film is measured. Therefore, the coating film was peeled off from a glass plate, crushed, a certain amount of the sample was put into an extractor, and extracted under reflux for one hour using a certain amount of acetonitrile as an extraction solvent.
The amount of initiator was determined using PC. The results are also shown in Table-2.

Table of evaluation results Curing time: Irradiation time of ultraviolet rays until the surface of the coating film is free of tack under the conditions shown in Example 1.Coating film properties: Physical properties after each composition is completely cured. The complete curing condition was an irradiation time of 1.5 times the respective curing time (excluding the color difference curing condition). The evaluation method for the physical properties of the coating film was as follows.

Hardness: Pencil hardness JIS K-5 4 0
0 Compliant Solvent Resistance: The number of times that gauze is thoroughly impregnated with MICK'' f. as a solvent and the coated surface is strongly pressed and rubbed back and forth until an abnormality occurs in the coated film.

Hot water resistance... After immersing the sample in 50C hot water for 24 hours,
Take it out and visually inspect the painted surface for abnormalities.

Heat resistance: Sample 2aot:' was kept in the atmosphere for 24 hours, then taken out and visually inspected for abnormalities on the coated surface.

Color difference: In order to make the conditions for each sample the same, the ultraviolet irradiation time for measuring color difference was all 10 seconds.

The color difference is between unpainted white acrylic board and Using a color difference meter as a difference from the painted board trace] added.

Odor criteria: Q: No odor, Δ: Slight odor, ×:
The proportion of the extracted unreacted initiator with obvious odor is shown based on the total amount of initiator blended in each composition as 100%.

Patent applicant: Mitsubishi Rayon Co., Ltd.

Claims (1)

[Scope of Claims] An acetophenone derivative radically polymerizable substance having at least one acryloyl group or methachlor group in the molecule, obtained by reacting the following two components (a) and (b) as a photopolymerization initiator; Component (a) of a photocurable resin composition characterized by consisting of ▲ Numerical formulas, chemical formulas, tables, etc. ▼ Component (b) Monoisocyanate having one acryloyl group or methacryl group in the molecule