JP2956245B2 - Photopolymerization initiator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymerization initiator capable of initiating polymerization of at least one ethylenically unsaturated polymerizable monomer or oligomer with near infrared light.

[0002]

2. Description of the Related Art Photopolymerization includes photo, screen printing, sheet-fed printing, lithographic printing, letterpress printing, metal surface processing, ink, printing board preparation, resist or photomask, black and white or color transfer color forming sheets or coloring. It is used for various purposes such as sheet making. Also,
Photopolymerizable compositions are also used in the area of dental technology.

In these applications, development of polymerization initiators has been actively promoted for the purpose of improving productivity by rapid curing (for example, Japanese Patent Application Laid-Open No. 22370/1987).
And JP-A-62-143044) and JP-A-2-2237.
No. 0 discloses an ultraviolet light curable ink composition containing a poly (meth) acrylate and an ultraviolet light polymerization initiator, and Japanese Patent Application Laid-Open No. Sho 62-14304.
No. 4 discloses a photocurable composition which uses a monovalent cationic dye-boron anion complex as a photopolymerization initiator, is encapsulated in microcapsules together with an ethylenically unsaturated compound, and can be cured by irradiation with visible light. I have.

[0004]

The photopolymerization cures rapidly by irradiating a composition comprising a photopolymerization initiator and a polymerizable monomer with light, but the amount of photopolymerization increases due to its characteristics. As the productivity increases, productivity is increasingly required, and a photopolymerization initiator having a higher curing speed and an excellent hardness of a cured product is desired. SUMMARY OF THE INVENTION An object of the present invention is to provide a photopolymerization initiator which starts polymerization by near infrared light having excellent transparency.

[0005]

According to the present invention, as a result of diligent studies on a metal complex having a specific boron anion in order to solve this problem, a photopolymerization initiator sensitive to near infrared light can be obtained. I have found something. That is, according to the present invention, a photopolymerization initiator comprising a metal complex having a boron anion represented by the general formula (1) having absorption in near infrared light can be obtained. Polymerization can be initiated by light in the infrared region. General formula (1);

[0006]

Embedded image (Wherein, R ₁ and R ₂ represent an alkyl group or a substituted alkyl group, and X represents a hydrogen atom, a halogen atom, an alkyl group,
Represents an alkoxy group or an acylamino group, Y represents a hydrogen atom, a halogen atom, or an alkyl group;
Represents 2 or 3. M represents Ni or Cu, and R ₃ , R ₄ , R ₅ and R ₆ each independently represent alkyl, aryl, alkaryl, allyl, aralkyl, alkenyl, alkynyl, silyl, alicyclic and saturated or unsaturated. saturated heterocyclic group, or a substituted alkyl, substituted aryl, substituted alkaryl, substituted allyl, substituted aralkyl, substituted alkenyl, a substituted alkynyl, R _3, R
₄ , at least one of R ₅ and R ₆ has 1 to 8 carbon atoms
And R _{3 to} R ₆ may have a cyclic structure to which two or more groups are bonded. )

In R ₁ and R ₂ of the metal complex having a boron anion used in the photopolymerization initiator of the present invention, the alkyl group is an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group or a propyl group. , A butyl group and a pentyl group; examples of the substituent in the substituted alkyl group include an acyloxy group such as an acetyloxy group and a propionyloxy group; an alkoxy group such as a methoxy group, an ethoxy group and a methoxyethoxy group; a methoxycarbonyl group; An alkoxycarbonyl group such as an ethoxycarbonyl group; a hydroxyl group; a cyano group; a halogen atom such as a chlorine atom or a bromine atom.

In X, a halogen atom includes a chlorine atom and a bromine atom, an alkyl group includes a methyl group and an ethyl group, an alkoxy group includes a methoxy group and an ethoxy group, and an acylamino group includes an acetyl group. Examples include an amino group, a propionylamino group, and a benzoylamino group. The halogen atom and the alkyl group in Y are the same as those in X.

In R ₃ , R ₄ , R ₅ and R ₆ , alkyl, aryl, alkaryl,
It can be selected from allyl, aralkyl, alkenyl, alkynyl, silyl, alicyclic and saturated or unsaturated heterocyclic groups, or substituted alkyl, substituted aryl, substituted alkaryl, substituted allyl, substituted aralkyl, substituted alkenyl, substituted alkynyl. , at least one among R _3, R _4, R ₅ and R ₆ are alkyl group having 1 to 8 carbon atoms atoms.

For example, triphenyl n-butyl boron anion, trianisyl n-butyl boron anion, tetra n-butyl boron anion, tri n-butyl (triphenylsilyl) boron anion, tri n-butyl (dimethylphenyl) (Silyl) boron anion, n-butyldiphenyl (triphenylsilyl) boron anion, and the like. Table 1 shows examples of metal complexes having a boron anion that are particularly useful in the present invention.

[0011]

[Table 1]

The photopolymerization initiator of the present invention is preferably used in combination with an oxygen scavenger capable of absorbing oxygen in a free radical chain process. Examples of oxygen scavengers include phosphine, phosphite, phosphonate, stannous salts and other compounds readily oxidized by oxygen; useful examples include trimethylbarbituric acid, 2-mercapto Benzoxazole, 2-mercaptobenzothiazole,
N, N-dimethyl-2,6-diisopropylaniline,
N, N-2,4,6-pentamethylaniline and the like.

Examples of the N, N-dialkylaniline include an alkyl, phenyl, acetyl, ethoxycarbonyl,
It is substituted with a carbonyl group, a carboxylate group, a silyl group, an alkoxy group, a phenoxy group, an acetyloxy group, a hydroxy group, a halogen group, or the like.A particularly preferred example is one in which the ortho position is substituted with an alkyl group. 2,6-diisopropyl-N, N-dimethylaniline, 2,6-diethyl-N, N-dimethylaniline, N, N, 2,4,6-pentamethylaniline and pt-butyl —N, N-dimethylaniline and the like.

The photopolymerization initiator of the present invention has a sensitizer of 4
Quaternary ammonium boron salt, quaternary phosphine boron salt,
By using N-phenylglycine or an organic peroxide together, the sensitivity of the initiator can be increased. That is, examples of quaternary ammonium boron salts include tetramethylammonium n-butyltriphenylboron, tetramethylammonium n-butyltrianisylboron,
Tetramethyl ammonium n-octyl triphenyl boron, tetramethyl ammonium n-octyl trianisyl boron, tetraethyl ammonium n-butyl triphenyl boron, tetraethyl ammonium n-butyl trianisyl boron, trimethyl hydrogen ammonium n-butyl triphenyl boron, triethyl hydrogen Ammonium n-butyl triphenyl boron, tetrahydrogen ammonium n-butyl triphenyl boron, tetramethyl ammonium tetrabutyl boron, tetraethyl ammonium tetrabutyl boron, tetra n-butyl ammonium tri n-butyl (triphenylsilyl) boron, tetramethyl ammonium Bird n
-Butyl (dimethylphenylsilyl) boron; and examples of quaternary phosphine boron salts include triphenylmethylphosphine n-butyltriphenylboron, triphenylethylphosphine n-butyltriphenylboron, triphenyl Methyl phosphine n-butyl trianisyl boron, triphenyl ethyl phosphine n-butyl trianisyl boron, tetraphenyl phosphine n-butyl triphenyl boron, tetraphenyl phosphine n-butyl trianisyl boron, triphenyl methyl phosphine tri n-butyl (triphenylsilyl) boron; triphenylethylphosphinetri-n-butyl (dimethylphenylsilyl) boron;

The organic peroxides used in the present invention are all conventional organic peroxides. In particular,
Diacetyl peroxide, dilauroyl peroxide dibenzoyl peroxide, p, p'-dichlorodibenzoyl peroxide, p, p'-dimethoxydibenzoyl peroxide, p, p'-dimethyldibenzoyl peroxide, p, p'-dinitrodibenzoyl peroxide, etc. Diacyl peroxides, tertiary-butyl hydroperoxide, cumene hydroperoxide,
Hydroperoxides such as 2,5-dimethylhexane-2,5-dihydroperoxide; ketone peroxides such as methyl ethyl ketone peroxide; tert-butyl peroxide benzoate;
Examples thereof include peroxycarbonates such as 4'-tetra- (t-butylperoxycarbonyl) benzophenone. Among these, dibenzoyl peroxide, 3,3 ', 4,4'-tetra- (t-butylperoxycarbonyl) benzophenone and the like are preferable.

Furthermore, the free-radical addition polymerizable or crosslinkable compounds for which the photopolymerization initiators according to the invention can be used include all customary ethylenically unsaturated compounds,
In particular, acrylic acid esters or methacrylic acid esters of monohydric alcohols or polyhydric alcohols or aromatic polycarboxylic acids containing 4- (meth) acryloyloxyl group and acid anhydrides thereof, and so-called urethane acrylates are provided below these esters. Or methacrylate, and the reactants known from U.S. Pat. No. 3,066,112, such as 2,2-bis (4- (3-methacryloxy-2-hydroxypropoxy) -phenyl) propane and di (methacryloxyethyl) trimethylhexa. Methylenediurethane, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane trimethacrylate, tetramethylo Methane tetramethacrylate,
Tetramethylolpropane trimethacrylate, tetramethylolpropane triacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, 4- (meth) acryloyloxymethoxycarbonylphthalic acid and its acid anhydride,
(Meth) acryloyloxyethoxycarbonylphthalic acid and its acid anhydride.

The photopolymerization initiator in the present invention may contain 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the ethylenically unsaturated compound. The sensitizer can be added in an amount of 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 1% by weight of the photopolymerization initiator. Further, an oxygen scavenger can be added in the same amount as the photopolymerization initiator. If necessary, inorganic additives, dyes and pigments as coloring agents, solvents and the like can be added.

Examples of applicable photopolymerization initiators according to the present invention include photopolymerization, screen printing, sheet-fed printing, lithographic printing, letterpress printing, metal surface processing, ink,
It can be used for producing a printed board, a resist or a photomask, a black and white or color transfer or coloring sheet or a coloring sheet, a toner for a copying machine, a capsule toner for a copying machine, and the like. Further, a composition comprising the photopolymerization initiator and an ethylenically unsaturated compound and a leuco dye or a dye having an absorption in the visible region can be used for producing a black or color transfer color-forming sheet or a color-forming sheet. Further, these compositions can be used by being encapsulated in microcapsules. In addition,
It can be applied as a photopolymerizable composition for dental treatment such as a denture with a denture, a dental prosthetic material and a dental filling composition, and a coating and adhesive composition for dental purposes. However, the photopolymerization initiator according to the present invention is not limited to these application examples.

As a specific example of application to a sheet for transfer color formation, a composition comprising a photopolymerization initiator and an ethylenically unsaturated and leuco dye is encapsulated in a microcapsule, and the microcapsule is made of a base paper or a film with polyvinyl alcohol. After coating on top and exposing using a near-infrared light lamp, when the transfer base paper is overlaid and pressed with a pressure roll, the microcapsules are broken according to the image and an image can be formed on the transfer base paper .

[0020]

EXAMPLES The present invention will be further described below with reference to examples.

Examples 1 to 9 Trimethylolpropane triacrylate 10 g Metal complex As shown in Table 2, N, N, 2,4,6-pentamethylaniline 0.02 g of a mixture was prepared to prepare Compositions 1 to 9. .

Examples 10 to 14 Pentaerythritol triacrylate 10 g Metal complex Shown in Table 2 Quaternary ammonium boron salt Shown in Table 2 A mixture comprising 0.02 g of N, N, 2,4,6-pentamethylaniline was prepared. Compositions 10 to 14 were made.

Examples 15 to 17 Trimethylolpropane trimethacrylate 6 g Urethane acrylate dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., U-108-A) 4 g Metal complex Shown in Table 2 Organic peroxide Shown in Table 2 N, N, A mixture consisting of 0.02 g of 2,4,6-pentamethylaniline was prepared to prepare Compositions 15 to 17.

Examples 18 to 20 Trimethylolpropane trimethacrylate 6 g Urethane acrylate dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., U-108-A) 4 g Metal complex Shown in Table 2 N, N, 2,4,6-pentamethyl Aniline 0.02 g Colorant for image formation (manufactured by Orient Chemical Co., Ltd.) Mixtures indicated in Table 2 were prepared to prepare Compositions 18 to 20.

Comparative Example 1 In place of the metal complex in Example 1, as shown in Table 2,
A sample was prepared in the same manner except that camphorquinone and hydroquinone monomethyl ether were used to prepare composition 21.

[0026]

[Table 2]

Examples 1 to 20 and Comparative Example 1 described above
The compositions 1 to 21 obtained in the above were colored using an applicator so as to have a thickness of 5 μm on carton paper, and irradiated with a dichroic coat type halogen lamp (1 W / cm ² ) for 0.1 second. It was pressed against art paper and evaluated for curing. The results are shown in Table 3.

[0028]

[Table 3]

[0029]

According to the present invention, a near-infrared light polymerization initiator which initiates polymerization by near-infrared light is provided.

Continuing from the front page (72) Inventor Kiichi Hosoda 5-1 Ogimachi, Kawasaki-ku, Kawasaki City Showa Denko KK Chemical Research Laboratory (58) Field surveyed (Int.Cl. ⁶ , DB name) C08F 2/46-2 / 50

Claims (3)

(57) [Claims] 1. A near-infrared light polymerization initiator comprising a metal complex having a boron anion represented by the general formula (1). General formula (1); (Wherein, R ₁ and R ₂ represent an alkyl group or a substituted alkyl group, and X represents a hydrogen atom, a halogen atom, an alkyl group,
Represents an alkoxy group or an acylamino group, Y represents a hydrogen atom, a halogen atom, or an alkyl group;
Represents 2 or 3. M represents Ni or Cu, and R ₃ , R ₄ , R ₅ and R ₆ each independently represent alkyl, aryl, alkaryl, allyl, aralkyl, alkenyl, alkynyl, silyl, alicyclic and saturated or unsaturated. saturated heterocyclic group, or a substituted alkyl, substituted aryl, substituted alkaryl, substituted allyl, substituted aralkyl, substituted alkenyl, a substituted alkynyl, R _3, R
₄ , at least one of R ₅ and R ₆ has 1 to 8 carbon atoms
And R _{3 to} R ₆ may have a cyclic structure to which two or more groups are bonded. ) 2. The near-infrared light polymerization initiator according to claim 1,
Quaternary ammonium boron salt, quaternary phosphine boron salt,
A near-red light polymerization initiator comprising a combination with a sensitizer selected from at least one of N-phenylglycine and organic peroxide. 3. A near-infrared photopolymerizable composition comprising the near-infrared photopolymerization initiator according to claim 1 and an ethylenically unsaturated compound.