JPH01230603A - photocurable composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photocurable composition that is easily crosslinked and cured by irradiation with light, and the cured coating film is odorless.

[Conventional technology]

Conventionally known photocurable compositions include unsaturated polyester resins, polyester polyacrylates,
Polyvalent acrylates such as epoxy polyacrylate, urethane polyacrylate, and polyol polyacrylate are used as photopolymerization initiators such as nohensoin ethers such as penzoin isoglobyl ether, benzyl ketals such as benzyl dimethyl ketal, and jetoxy Examples include compositions containing a combination of an acetophenone derivative such as acetophenone, a ketone such as benzophenone, and N-methyljetanolamine.

[Problems to be Solved] When these photocurable compositions are irradiated with light, they are rapidly crosslinked and cured by radicals generated from the photopolymerization initiator. However, these cured products have the disadvantage that they rarely have an unpleasant odor even though they are completely cured by sufficient light irradiation. It has been revealed that the cause of this is the volatilization of excess unreacted photopolymerization initiator that remains without participating in the polymerization reaction.

In fact, it is known that when these cured coatings are crushed, placed in an extraction vessel, and extracted with an extraction solvent such as tetrahydrofuran, as many as 50 to 80 unreacted substances of the photopolymerization initiator blended are detected.

[Means to solve the problem]

Considering the above-mentioned current situation, the present inventors have proposed that by introducing a polymerizable ethylenically unsaturated group into the photopolymerization initiator, unreacted excess initiator that does not participate in photopolymerization initiation can also be incorporated into the crosslinked cured product. As a result of examining photocurable compositions using such novel initiators based on the judgment that no unpleasant odor will be generated, the following (a) and (b) photopolymerization initiators were found.
) 1(C) A photocurable composition obtained by reacting the three components and using an acetone enone derivative having at least one (solid acryloyl group or methacryloyl group in the molecule) as a photopolymerization initiator has no unpleasant odor. It was found that the cured product was free of .

4-(2-hydroxyethoxy)-, which is the (a) component that is the raw material for the polymerizable acetophenone derivative used in the present invention.
Phenyl-2-(2-hydroxy)propyl ketone is commercially available from West German Merck & Co. under the trade name Darocure 2959 and can be used as is.

Specific examples of the polyiso7anate compound used as component (b) of the present invention include, for example, ethylene diisocyanate), 1,2-diisocyanatopropane, 1,3-
Diisocyanatopropane, 1,6-diisocyanatohexane, trimethylhexamethylene diisocyanate, 1
．． 2-diynecyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diynecyanatocyclohexane, 1,2-diynecyanatododecane, 0-diisocyanatobenzene, m-diisocyanatobenzene,
p-diisocyanatobenzene, bis(4-isocyanatocyclohexyl)methane, bis(4-isocyanatophenyl)methane, toluene diisocyanate, 53'-dichloro-4,4'-diisocyanatobiphenyl, tris(4- isocyanatophenyl)methane, 1,5-diisocyanatonaphthalene, hydrogenated toluene diisocyanate, inphorone diiso7anate, ~45-tris(6-
(indianatohexyl)biuret and hyphenyl-blocked toluene diisocyanate.

Among these, aliphatic polyisocyanates are preferred from the viewpoint that the initiator obtained by the reaction is unlikely to yellow.

Specific examples of the compound having at least one hydroxyl group and at least one (meth)acryloyl group in one molecule as component (C) used in the present invention include, for example, 2-hydroxyethyl (meth)acrylate; 2-Hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2- expressed by the general formula % (where R or OH, n = 1 to 5)
Hydroxyethyl (meth)acrylic V-) derivative, (Rd
2-hydroxypropyl (meth)acrynaute derivative represented by H or CH8, n=1-5), OHgeC000CH! 04o+(:!ca, ca, an
, an, aH, o almost H (R#'iH or CHs, n=1
〜5) 2-Hydroxy(meth)acrylate with 1-cabrolactone added General formula c a, -a a o o (:! H, C horse 0 (-R'-0) H (R is H or OE, R' is Cu2
~04 Alki V7, n = 1-5) 2
- Monomers with ethylene oxide, propylene oxide or diethylene oxide added to hydroxyethyl (meth)acrylate, monoepoxy compounds such as pentaerythritol triacrylate, methyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, etc. (meth) acrylic Examples include monomers to which an acid has been added.

When the polymerizable photopolymerization initiator of the present invention is synthesized using these three component raw materials, the ratio of each component is preferably as follows.

(Number of moles of primary OH groups in component (a)) + (Number of moles of OH groups in component (0)) ≧ (Number of moles of Neo group in component (b)), and ((a) ) Number of moles of component) ≦ (Number of moles of component) The order of the reaction is not particularly limited, and if kept, (
1) Method of reacting component (a) with component (C) after reacting component (21 (Is)), reacting component (C) with component (21), and then reacting component (a). or (3) a method of simultaneously mixing and reacting the three components.

The catalyst used in the above reaction is not particularly limited, and may be a tin-based catalyst such as dibutyltin laurate, which is used in general urethane reactions.

The above reaction can be carried out without a solvent, or, if necessary, in a solvent or monomer that is inert to the isocyanate compound.

The temperature conditions for carrying out the above reaction range from room temperature to 70-80°C.
The range is around ℃.

The ethylenically unsaturated compound used in the present invention is not particularly limited as long as it is a radically polymerizable compound, and can be arbitrarily selected depending on the purpose.

For example, unsaturated polyester, polyol poly(meth)
Acrylate, polyester poly(meth)acrylate, epoxy poly(meth)acrylate, urethane poly(
Typical examples include meth)acrynaut, polyacrylic poly(meth)acrylate, melamine poly(meth)acrylate, polysiloxane poly(meth)acrylate, and polyamide poly(meth)acrylate. These may be used alone or in combination of two or more. In addition, together with these compounds, 1
Other monomers that can be combined can also be used, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl acrylate, (meth)acrylate, etc.
n-butyl acrylate, tert-(meth)acrylate
Butyl, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-(meth)acrylate
Nonyl, cyclohexyl (meth)acrylate, (meth)
Benzyl acrylate, dicyclopentenyl (meth)acrylate, (meth)acrylic modified 2-dicyclopentenoxyethyl, methoxyethyl (meth)acrylate, (meth)acrylate
Ethoxyethyl acrylate, butoxyethyl (meth)acrylate, (meth)acrylic/L/acid methoxyethoxyethyl, ethoxyethoxyethyl (meth)acrylate, (
Tetrahydrofurfuryl meth)acrylate, 2-hydroxyethyl (meth)acrylate, (meth)acrylic acid 2
- Hydroxypropyl, (meth)acrylic acid derivatives such as 4-droxybutyl (meth)acrylate, nitrogen-containing vinyl compounds such as N-vinyl 2-pyrrolidone, N-vinylimidazole, N-vinylcaglolactam, styrene,
Aromatic vinyl compounds such as α-methylstyrene and vinyltoluene, i! Examples include vinyl esters such as vinyl rIE acid, vinyl propionate, and vinyl benzoate.

Furthermore, a thermoplastic resin may be added to the composition of the present invention within a range that does not impair photocurability f. Specific examples include cellulose derivatives such as nitrocellulose, acetylcellulose, acetylbutyrylcellulose, ethylcellulose, and methylcellulose, vinyl chloride, vinylidene chloride, vinyl acetate, polyvinyl alcohol, polyvinyl ether, acrylic resin, styrene resin, polyamide, and fluorine. Examples include resins, thermoplastic resins such as petroleum resins, processed resins such as alkyd resins and rosin esters, rubber derivatives such as chlorinated rubber, and chlorinated rubber.

The amount of the polymerizable acetophenone derivative used in the composition of the present invention is in the range of 1 to 30% by weight, preferably Vi1 to 20% by weight.

In the present invention, a general photopolymerization initiator may be used in combination within a range that does not impair the improvement of unpleasant odor, which is the objective of the present invention. Specific examples thereof include benzophenone, benzoin methyl ether, benzine ethyl ether, pensoin isofthyl ether, penzoin isoglobyl ether, benzoyl benzoic acid, methyl benzoyl benzoate,
Benzyl dimethyl ketal, 3'-dimethyl-4-methoxybenzophenone, 1-(4-dodecylphenyl)
-2-hydroxy-2-methylpropan-1-one, 1
-Hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-(4-1soglobylphenyl)-2-hydroxy-2-methylpropan-1- On, methyl phenyl glyoxylate, ethyl phenyl glyocinate, 2
-Methyl-1-C4-C'fruthio)phenylco2-
Morpholinoglopanone-1, tetra(t-butylperoxycarbonyl)benzophenone, 2-chlorothioxanthone, 2.4-diethylthioxanthone, 2.4-diisoglobilthioxanthone, 2.4-dimethylthioxanthone, 4-benzoyl- 4'-methyldiphenyl sulfide, 2.2-jethoxyacetophenone, 2.
Examples include 2-dibutoxyacetophenone and jetoxyphenylacetophenone.

The composition of the present invention contains a polymerization inhibitor for preventing gelation during storage, hydroquinone, p-benzoquinone, hydroquinone monomethyl ether, p-tart, etc.
-7'Tylcatechol, monotart-butylhydroquinone, α-naphthol, pyrogallol, etc., and various other additives, such as leveling agents, slip agents, antifoaming agents Δ1, anti-sagging agents, anti-cissing agents, wetting agents, and dispersion agents. agent,
Antisettling agents and the like can also be used.

Dyes and pigments commonly used for skin coloring can be added to the composition of the present invention.

One or more inert volatile organic solvents can be used in the composition of the present invention to adjust its viscosity. Examples include acetate esters such as methyl acetate, ethyl acetate, isopropyl acetate, propyl acetate, butyl acetate, amyl acetate, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, hexane, cyclohexane, Examples include hydrocarbon solvents such as toluene and xylene, alcohol solvents such as ethanol, gropanol, isobutanol, butanol, and isobutanol, cellosolve, cellosolve acetate, butylceronlube, and the like.

The composition of the present invention can be manufactured simply by uniformly mixing the above-mentioned components. Mixing is generally carried out at room temperature, but may be heated in some cases.

To cure the composition of the present invention, ultraviolet rays from a low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, xenon lamp, gallium lamp, metal halide lamp, carbon arc lamp, sunlight, etc. are applied in air or in a kiln. Just irradiate it.

The present invention will be explained below using real 2111ii sequences. In addition, in the actual column, parts indicate heavy parts.

Synthesis sequence 1> 4-(2-hydroxyethoxy)phenyl-2-(2-
Hydroxy) propyl ketone 22.4f (α1 mole) and isophorone diisocyanate 22.62 (0,,102
mole) and diptyltin laurate α0071 as a catalyst.
was weighed into a flask and reacted at 70°C for 4 hours with stirring.
Add the polymerization inhibitor (α105 mol) dropwise and shitehydroquinone monoethyl ether (MKHQ) to C1,
06 was added to continue the reaction, and the reaction was terminated when the 1100 reaction rate became 98 or higher, to obtain the desired polymerizable photopolymerization initiator A. This reaction product was a solid at room temperature and had a number average molecular weight 1 of 610 according to GPO.

Synthesis sequence 2> 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone 22.4f (α1 mol)
and hydrogenated diphenylmethane diisocyanate) 2 & 9F (
(L 102 mol) and diptyltin laurate as a catalyst were weighed into an α09r1&: flask, and while stirring,
After reacting at 0°C for 4 hours, immediately after dropping 2-hydroxypropyl acrylate 157F (105 moles of CL), 111L061 of MEHQ was added to continue the reaction bc.

The reaction was completely completed when the reaction rate reached 98% or more, and the desired polymerizable photopolymerization initiator B was obtained.

This reaction product was a solid at room temperature, and the number average molecular m according to GPO was 660.

[Practice P111 Urethane acrylate (Diabeam UK-6035,
(manufactured by Mitsubishi Rayon Co., Ltd.) and 40 parts of tetraethylene glycol cyacrylate as a photopolymerization initiator. ) were mixed to obtain a photocurable composition.

This composition was applied to a white acrylic plate to form a coating film of 20 μm, and irradiated with ultraviolet (UV) rays at a distance of 20 cm under an 80 W/α high-pressure mercury lamp. The physical properties of the film were measured and the results are shown in Table 1.

In addition, this composition was 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 was measured. To do this, 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 t was determined using APA. The results are shown in Table 1.

[Example 2] Example 2 except that 12.6 parts of the polymerizable photoinitiator B obtained in Synthesis Example 2 was used as the photopolymerization initiator in Example 1 (Q, 02 mol% relative to the monomer mixture). Samples were prepared in the same manner as Example 1, and the curing time, odor, physical properties of the coating film, and amount of unreacted initiator were measured in the same manner as in Example 1. The obtained results are shown in Table 1.

[Comparison rows 1 to 4] Photopolymerization initiator t in Example row 1 (a) Phenyl 2-
(2-Hydroxy)furobylketone 528 parts (α02 mol% based on the monomer mixture), (1)) 4-(2-hydroxyethoxy)phenyl-2-(2-hydroxy)furobylketone 4.49 parts (based on the monomer mixture α02
(mol%), (C) penzoin inglobil ether a0
9 parts ([102 mol% based on monomer mixture) or (d
) 1-Hydroxycyclohexylphenylketo 24.0
Samples were prepared in the same manner as in Example 1 except that 9 parts (102 mol % based on the monomer mixture) were used, and the curing time, odor, coating film properties, and unreacted initiator It were measured in the same manner as in Example 1. The results obtained are shown in Table 1.

[Run 3] 40 parts of bisphenol epoxy acrylate (VR-77 manufactured by Showa Kobunshi Co., Ltd.), polyester polyacrylate (Aronix M-6 manufactured by Toagosei Kagaku Kogyo Co., Ltd.)
200) 50 parts and t6-hexanethiol diacrylate V
7.2 parts of a polymerizable photopolymerization initiator A I (102 moles based on the monomer mixture) were mixed with 30 parts of the photocurable composition to obtain a photocurable composition. Samples were prepared in the same manner as in Example 1, and the curing time, odor, physical properties of the coating film, and amount of unreacted initiator were determined in the same manner as in Example 1.

The nine results obtained are shown in Table 1.

[Effects of the Invention] As detailed above, the composition of the present invention can be used in various fields such as coating materials, inks, cast molding applications, etc., and its effects are extremely large. .

Claims (1)

[Claims] 1. A photopolymerization initiator that is an acetophenone derivative having at least one (meth)acryloyl in the molecule, obtained by reacting the following three components (a), (b), and (c): and a photocurable composition comprising an ethylenically unsaturated compound. (a) Component ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (b) Component Polyisocyanate compound (c) Component Compound having at least one hydroxyl group and at least one (meth)acryloyl group in one molecule