JP3308068B2 - Photopolymerizable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photopolymerizable composition, more specifically, a compound having a polymerizable ethylenically unsaturated double bond, a specific aromatic ketone compound-based photopolymerization initiator and an intramolecular compound. A photopolymerizable composition having improved photosensitivity and weather resistance by adding a compound having a 1,2,2,6,6-pentamethylpiperidyl group to the composition.

[0002]

2. Description of the Related Art A photopolymerizable composition containing a photopolymerization initiator (photosensitizer) in a compound having a polymerizable ethylenically unsaturated double bond is produced by heat. It has the advantages of being able to omit the drying process, to be cured in a short time, to be able to easily produce products with complicated shapes, and to have less environmental pollution. Photocurable ink, photocurable paint or coating agent, photocurable It is widely used as a conductive adhesive, a photosensitive lithographic printing plate, a photoresist for printed circuit boards, and the like.

It is well known that an aromatic ketone compound such as xanthone, thioxanthone or anthraquinone is used as a photopolymerization initiator used in the photopolymerizable composition. These aromatic ketone compounds, when used alone, have an insufficient curing rate of the photopolymerizable composition, and therefore have an aliphatic or aromatic hydroxyl group such as triethanolamine, methyldiethanolamine, bisdimethylaminobenzophenone, and dimethylaniline. Tertiary amine compounds have been used in combination as photopolymerization accelerators.

[0004] However, even when these tertiary amine compounds are used in combination, the effect is still not sufficient, and further improvement has been demanded. Also, Japanese Unexamined Patent Publication No.
JP-A-20304 proposes to use a perbenzoic acid compound in combination, and JP-A-2-38404 proposes to use in combination with camphorquinone. The light sensitivity of the objects was not satisfactory enough.

Further, when these photopolymerizable compositions are used as photocurable paints for automobiles or the like, or when used as protective coatings for various cards, photographs, etc., cured products of the photopolymerizable compositions are used. Weather resistance is required.

[0006] It is well known that additives such as various antioxidants, ultraviolet absorbers, hindered piperidine-based light stabilizers and the like are appropriately used in combination to improve the weather resistance of ordinary synthetic resins. It is also known to use these additives in compositions, for example, see JP-A-4-209666.
Japanese Patent Application Laid-Open Publication No. H11-216, proposes to improve the weather resistance of a cured product by adding an antioxidant, an ultraviolet absorber and a hindered amine compound to a specific photopolymerizable composition.

However, since the photopolymerizable composition generates radicals upon irradiation with ultraviolet rays and causes the radicals to be polymerized in a chain, the photopolymerizable composition may inhibit photopolymerization depending on the additive used. Although it was necessary to find an optimal combination of a photopolymerization initiator and an additive, an optimal additive for a photopolymerizable composition using an aromatic ketone compound such as xanthone, thioxanthone or anthraquinone as a photopolymerization initiator was found. The fact is that a photopolymerizable composition which gives a cured product having high photosensitivity and improved weatherability has not yet been obtained.

Accordingly, an object of the present invention is to provide a high light sensitivity,
Another object of the present invention is to provide a photopolymerizable composition that gives a cured product having excellent weather resistance.

[0009]

In view of the above situation, the present inventors have remarkably increased the photopolymerization sensitivity (photosensitivity) of a photopolymerizable composition using a xanthone, thioxanthone or anthraquinone compound as a photopolymerization initiator. Not only to improve,
As a result of intensive studies to obtain a polymerization accelerator that also significantly improves the weather resistance of the cured product of the photopolymerizable composition, it has a 1,2,2,6,6-pentamethylpiperidyl group in the molecule. The present inventors have found that the above object can be achieved by including a compound in the photopolymerizable composition, and have reached the present invention.

That is, the present invention relates to 100 parts by weight of a compound having a polymerizable ethylenically unsaturated double bond, represented by the following general formula (I): 0.01 to 20 parts by weight of the compound and 1,2,2
It is intended to provide a photopolymerizable composition containing 0.01 to 10 parts by weight of a compound having a 2,6,6-pentamethylpiperidyl group.

[0011]

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Hereinafter, the photopolymerizable composition of the present invention will be described in detail.

The compound having a polymerizable ethylenically unsaturated double bond used in the present invention includes a monomer and a prepolymer obtained by polymerizing the monomer, and these are preferably liquid at room temperature.

Examples of the compound having a polymerizable ethylenically unsaturated double bond include α, β such as acrylic acid, methacrylic acid, fumaric acid, maleic acid and itaconic acid.
-Unsaturated carboxylic acids and ester derivatives of these α, β-unsaturated carboxylic acids with monohydric or polyhydric alcohols.

As the above ester derivatives, specifically, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, ethylene glycol di (meth) acrylate, poly (n = 2-14) ethylene glycol di (meth) acrylate, poly (n = 2 to 14) propylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri ( (Meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropanetetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acryl Unsubstituted alcohols over preparative like (meth) acrylate; trimethylolpropane obtained by adding ethylene oxide and / or propylene oxide, ditrimethylolpropane, pentaerythritol, tetra-hexa (meth) of dipentaerythritol
(Meth) acrylates of alkoxylated polyhydric alcohols such as acrylates; adducts of compounds having a glycidyl group such as bisphenol A diglycidyl ether and trimethylolpropane triglycidyl ether with (meth) acrylic acid; hydroxyethyl (meth) acrylate A (meth) acrylate compound having at least one hydroxyl group and a polycarboxylic acid such as phthalic acid or tolylene diisocyanate, diphenylmethane diisocyanate,
Reaction products with a polyisocyanate such as hexamethylene diisocyanate, and the like.

In the present invention, as the compound having a polymerizable ethylenically unsaturated double bond, in addition to the above α, β-unsaturated carboxylic acid ester derivative,
β-unsaturated carboxylic acid amide derivatives, vinyl alcohol derivatives, styrene, α-methylstyrene, vinyltoluene and the like can also be used.

In the compound represented by the above general formula (I) used in the present invention, examples of the halogen atom represented by R ₁ and R ₂ include chlorine, bromine and fluorine, and examples of the alkyl group include methyl , Ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, amyl, hexyl, octyl, isooctyl, 2-ethylhexyl, isononyl, decyl, isodecyl, dodecyl and the like, and the alkoxy group is derived from the above alkyl group. Alkoxy group to be used.

Accordingly, the compounds represented by the above general formula (I) include xanthone derivatives such as xanthone, 1,5-dimethoxyxanthone, 1,6-dimethoxyxanthone and 1,7-dimethoxyxanthone (where X is an oxygen atom Thioxanthone, 2-chlorothioxanthone,
2-methylthioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-dimethylthioxanthone,
Thioxanthone derivatives (compounds where X is a sulfur atom) such as 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 1-chloro-4-propyloxythioxanthone; anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 2-chloroanthraquinone, Examples include anthraquinone derivatives (compounds in which X is a carbonyl group) such as methylanthraquinone and 2-ethylanthraquinone. Among these compounds, a thioxanthone derivative in which X is a sulfur atom has a large effect as a photopolymerization initiator. preferable.

The amount of the compound represented by the general formula (I) is 0.01 to 20 parts by weight, preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the polymerizable compound having an ethylenically unsaturated double bond. If the amount is less than 0.01 part by weight, sufficient photosensitivity cannot be obtained, so that the progress of photopolymerization is insufficient. This is not preferred because not only is the useless because no increase in sensitivity is observed, but also the storage stability tends to decrease.

In the present invention, 1,2,2
Examples of the compound having a 2,6,6-pentamethylpiperidyl group include 1,2,2,6,6-pentamethylpiperidinol and derivatives thereof, 1,2,2,6,6
-Pentamethylpiperidylamine and derivatives thereof, and in particular, carboxylic acid ester derivatives of 1,2,2,6,6-pentamethylpiperidinol represented by the following general formula (II): However, the effect is large and preferable.

[0021]

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In the general formula (II), examples of the aliphatic, aromatic or alicyclic carboxylic acid having 1 to 4 valences which give the residue of the carboxylic acid represented by A include acetic acid, propionic acid and butyric acid. Octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, acrylic acid, methacrylic acid, oleic acid, linoleic acid, benzoic acid, toluic acid, cyclohexanecarboxylic acid, 4-butylcyclohexanecarboxylic acid, succinic acid, glutaric acid , Adipic acid,
Azelaic acid, sebacic acid, dodecanedioic acid, phthalic acid,
Isophthalic acid, terephthalic acid, tetrahydrophthalic acid,
Hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, tricarballylic acid, 1,2,3-butanetricarboxylic acid, 3-butene-1,2,3-tricarboxylic acid,
Trimellitic acid, trimesic acid, 1,2,3,4-butanetetracarboxylic acid, pyromellitic acid and the like can be mentioned.

In the above general formula (II), the divalent or tetravalent aliphatic, aromatic or alicyclic carboxylic acid which gives the residue of the carboxylic acid represented by B includes the carboxylic acid represented by A Among the carboxylic acids that provide the acid residue, dicarboxylic acids having a valency of 2 to 4 are exemplified.

In the above general formula (II), the glycol giving the residue of the glycol compound represented by Z is
For example, ethylene glycol, diethylene glycol,
Propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,
10-decanediol, 2,2-bis (4-hydroxycyclohexyl) propane, 2,2, -bis (4- (2
-Hydroxyethoxy) phenyl) propane, 3,9-
Bis (1,1-dimethyl-2-hydroxyethyl)-
2,4,8,10-tetraoxaspiro [5.5] undecane and the like.

In the general formula (II), examples of the alkyl group represented by R include methyl, ethyl, propyl, butyl, isobutyl, amyl, hexyl, isoheptyl, octyl, isooctyl, 2-ethylhexyl, nonyl,
Decyl, isodecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl,
Examples thereof include groups having 1 to 18 carbon atoms such as isooctadecyl.

Therefore, 1,2,2,6,6
Specific examples of the compound having a -pentamethylpiperidyl group include, for example, 1,2,2,6,6-pentamethylpiperidyl benzoate, 1,2,2,6,6-pentamethylpiperidyl stearate, 1,2 , 2,6,6-pentamethylpiperidyl acrylate, bis (1,2,2
2,6,6-pentamethylpiperidyl) succinate,
Bis (1,2,2,6,6-pentamethylpiperidyl)
Adipate, bis (1,2,2,6,6-pentamethylpiperidyl) sebacate, monomethyl-mono-1,2,2
2,6,6-pentamethylpiperidyl sebacate, bis (1,2,2,6,6-pentamethylpiperidyl) phthalate, bis (1,2,2,6,6-pentamethylpiperidyl) hexahydrophthalate, Tris (1, 2,
2,6,6-pentamethylpiperidyl) -1,2,3-
Butanetricarboxylate, tris (1,2,2,
6,6-pentamethylpiperidyl) trimellitate, tetrakis (1,2,2,6,6-pentamethylpiperidyl) -1,2,3,4-butanetetracarboxylate, mono (isotridecyl) -tris (1,2 , 2,
6,6-pentamethylpiperidyl) -1,2,3,4-
Butanetetracarboxylate, di (isotridecyl)
-Bis (1,2,2,6,6-pentamethylpiperidyl) -1,2,3,4-butanetetracarboxylate, monotridecyl-tris (1,2,2,6,6-pentamethylpiperidyl)- 1,2,3,4-butanetetracarboxylate, 3,9-bis (1,1-dimethyl-2- (tris (1,2,2,6,6-pentamethylpiperidyloxycarbonyl) butylcarboxy) ethyl ) -2,4,8,10-tetraoxaspiro [5.
5] Undecane and the like.

The amount of the compound having a 1,2,2,6,6-pentamethylpiperidyl group in the molecule is 0.1 to 100 parts by weight of the compound having a polymerizable ethylenically unsaturated double bond. 01 to 10 parts by weight, preferably 0.1
If the amount is less than 0.01 part by weight, sufficient photosensitivity and weather resistance of the cured product cannot be obtained.
If the amount exceeds 0 parts by weight, no further increase in the effect is observed, and it is useless.

The photopolymerizable composition of the present invention may contain a coloring agent such as a dye or a pigment. Examples of the coloring agent include fuchsin, auramine base, crystal violet, Victoria Pure Blue, Malachite Green,
Methyl orange, Acid Violet RRH and the like.

Further, the photopolymerizable composition of the present invention may contain a binder resin, a thermal polymerization inhibitor, an ultraviolet absorber, a plasticizer, an adhesion promoter, a filler such as talc, other light A well-known additive such as a polymerization accelerator may be added.

The photopolymerizable composition of the present invention can be prepared by dissolving or dispersing the above-mentioned components in a solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, chloroform, carbon tetrachloride, methylene chloride, and methanol. By dissolving and dispersing the mixture in ethanol, ethanol, or the like, it can be used as a solution-type photopolymerizable composition containing a solvent, or as a solventless photopolymerizable composition without using these solvents.

The photopolymerizable composition of the present invention may be directly applied to a substrate by a known means such as a roll coater, curtain coater, spray, various kinds of printing and immersion, or a support such as a film. After the application, a photopolymerizable composition layer may be formed on a support to form a photopolymerizable element, and then applied to a substrate, and the method is not particularly limited.

The photopolymerizable composition of the present invention can be used in various applications such as photocurable coatings, photocurable inks, photosensitive printing plates, photoimage forming systems, and photoresists. Is not particularly limited.

The light source used for photocuring the photopolymerizable composition of the present invention is not particularly limited.
A material that emits light of 300 to 450 nm, such as a mercury vapor arc, a carbon arc, and a xenon arc, can be used.

[0034]

The photopolymerizable composition of the present invention will be described in more detail with reference to the following examples. However, the invention is not limited by these examples.

Example 1 Epoxy acrylate (R-55, manufactured by Nippon Kayaku) was used as a compound having a polymerizable ethylenically unsaturated double bond.
1) Using a mixture of 75 parts by weight and 25 parts by weight of trimethylolpropane triacrylate, 1.5 parts by weight of diethylthioxanthone and 1.5 parts by weight of an amine compound (shown in the following [Table 1]) were added thereto. A photopolymerizable composition was prepared.

This photopolymerizable composition was coated on a polyethylene terephthalate film so as to have a film thickness of 25 μm, and exposed at 50 mJ / cm ² using a 3 kW high-pressure mercury lamp.
At this time, in order to be able to evaluate the light sensitivity, a negative film (optical density 0.05 was set as the first step, and the optical density was set to 0.15 for each step) so that the light transmission amount was reduced stepwise. Increasing step tablets) were used.

Next, the uncured portion was removed, and the photosensitivity of the photopolymerizable composition was evaluated by measuring the number of steps (curing steps) of the step tablet of the obtained photocured film.
The higher the number of steps of the step tablet (the number of curing steps), the higher the light sensitivity.

The surface gloss (6) after the cured sample was exposed to a sunshine weather meter for 1000 hours.
(A gloss of 0 degree) was measured, and a gloss remaining ratio after exposure to a gloss before exposure was determined. The results are shown in Table 1 below.

[0039]

[Table 1]

Example 2 As an amine compound (piperidyl compound), bis (1,
2,2,6,6-pentamethyl-4-piperidyl)-
The number of curing stages was measured in the same manner as in Example 1 except that 1,2,3,4-butanetetracarboxylate was used, and diethylxanthone was used in place of the photopolymerization initiator described in Table 2 below. The sensitivity was evaluated. The results are shown in Table 2 below.

[0041]

[Table 2]

Example 3 As a polymerizable compound having an ethylenically unsaturated double bond, 40 parts by weight of Alonix M-210 and 20 parts by weight of M-240 manufactured by Toa Gosei Chemical Co. were used, and polymethyl methacrylate was used as a binder. 40 parts by weight, p-dimethylaminobenzoic acid ethyl ester 1 part by weight, 2,4
3 parts by weight of diethylthioxanthone and 1 part by weight of a piperidine compound (shown in [Table 3] below) were added, and 400 parts by weight of dichloromethane was added and dissolved to prepare a photopolymerizable composition.

This photopolymerizable composition was applied on an aluminum plate so as to have a thickness of 5 μm, and dried at 60 ° C. for 10 minutes to form a photosensitive layer, on which polyvinyl alcohol was applied to a thickness of 3 μm. And used as a sample.

Using this sample, the number of curing stages was measured and the light sensitivity was evaluated in the same manner as in Example 1. The results are shown in Table 3 below.

[0045]

[Table 3]

As shown in the above examples, when thioxanthone, xanthone or anthraquinone is used as a photopolymerization initiator, a 1,2,2,6,6-pentamethylpiperidine compound or another amine is used. The compound used in combination with the compound exhibits an excellent effect as a photopolymerization accelerator. That is, it is clear that the photopolymerizable composition of the present invention has high photosensitivity, and also significantly improves the weather resistance of the cured product.

On the other hand, when an aromatic ketone compound other than the present invention such as benzophenone is used as a photopolymerization initiator, the 1,2,2,6,6-pentamethylpiperidine compound becomes a photopolymerization accelerator. Does not show any effect. Further, the 2,2,6,6-tetramethylpiperidine compound having a structure similar to that of the 1,2,2,6,6-pentamethylpiperidine compound of the present invention reduces the weather resistance of a cured product of the photopolymerizable composition. Although the effect of improving is observed, it shows no effect as a photopolymerization accelerator, that is, the photosensitivity of the photopolymerizable composition is low, and the effect of the present invention is exhibited only when a specific combination is used. Obviously, it is very specific.

[0048]

The photopolymerizable composition of the present invention has high photosensitivity and gives a cured product having excellent weather resistance.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Toshinori Kono 5-2-13-1 Shirahata, Urawa-shi, Saitama Asahi Denka Kogyo Co., Ltd. (56) References JP-A-2-255772 (JP, A) JP JP-A-4-209966 (JP, A) JP-A-2-22305 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 2/44-2/50

Claims (3)

(57) [Claims] 1. A compound having a polymerizable ethylenically unsaturated double bond, 100 to 100 parts by weight, a compound represented by the following general formula (I): 0.01 to 20 parts by weight, and A photopolymerizable composition containing 0.01 to 10 parts by weight of a compound having a 1,2,2,6,6-pentamethylpiperidyl group. Embedded image 2. In the general formula (I) of the above formula 1,
2. The photopolymerizable composition according to claim 1, wherein X is a sulfur atom. 3. The method according to claim 1, wherein the compound having a 1,2,2,6,6-pentamethylpiperidyl group is 1,2,2,6,6-
3. The photopolymerizable composition according to claim 1, which is a carboxylic acid ester compound of pentamethylpiperidinol.