JP3296454B2 - Photocurable 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 photocurable composition which contains a small amount of residual monomers, catalysts and other leaches from a polymerized and cured product.

[0002]

2. Description of the Related Art In general, a photocurable composition contains a polymerizable monomer and a photopolymerization initiator as essential components. As the photopolymerization initiator, a photosensitizer such as an aromatic ketone or camphorquinone is generally used in combination with a polymerization accelerator such as an amine compound.

[0003]

Since the photocurable composition is liable to inhibit polymerization activity by an acidic group-containing monomer or oxygen used for imparting adhesiveness, an amine compound as a polymerization accelerator is used. The use of a large amount is required, and as a result, there are disadvantages such as insufficient surface hardness after curing and an increase in unpolymerized monomers in the deep part, resulting in a decrease in adhesive strength when used as an adhesive. .

[0004]

The inventors of the present invention have conducted various studies to solve the above-mentioned defects of the photopolymerization initiator comprising a photosensitizer and an amine compound. The present inventors have found that by using an aminobenzene compound, it is possible to obtain a highly curable photocurable composition with less polymerization inhibition by an acidic group-containing monomer or oxygen, and have completed the present invention.

That is, the present invention comprises (a) a (meth) acrylate monomer, (b) a photosensitizer, and (c) a polymerization accelerator, wherein (c) a polymerization accelerator represented by the following general formula:

[0006]

Embedded image

Wherein R ₁ is a lower alkyl group;
₁ and X ₂ are a hydroxyl group or CH ₂ ＣC (R ₂ ) COO—
A photocurable composition characterized by being an aminobenzene compound represented by｝ except that X ₁ and X ₂ are both hydroxyl groups, wherein R ₂ represents a hydrogen atom or a methyl group. It is.

[0008] One of the components of the photocurable composition of the present invention is a (meth) acrylate monomer. As the (meth) acrylate-based monomer, known monomers polymerized by a photopolymerization catalyst can be used without any particular limitation.

A specific example of the (meth) acrylate monomer that is generally preferably used is methyl (meth).
Acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) Monofunctional (meth) such as acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, and methoxydiethylene glycol (meth) acrylate ) Acrylate monomers; ethylene glycol di (meth) acrylate, diethine glycol di (meth) acrylate, triethylene glycol di (meth) acrylate,
Tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-
Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, bisphenol A di (meth) acrylate, 2 , 2'-bis [(meth) acryloyloxypolyethoxyphenyl] propane, 2,
Such as 2'-bis [4- (3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane, trimethylolpropane (meth) acrylate, trimethylolethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, etc. A functional (meth) acrylate monomer or the like is used.

When the photocurable composition of the present invention is used as an adhesive, an acidic group-containing monomer having a carboxylic acid group or a phosphoric acid group in the molecule is used as the above (meth) acrylate monomer. It is preferable to use the mixture.

Preferred examples of the acidic group-containing monomer are as follows:

[0012]

Embedded image

[Wherein R ₃ is an alkyl group or a hydrogen atom,
R ₄ is a divalent to tetravalent organic residue having 2 to 20 carbon atoms, Y is a carboxyl group (when l = 2, Y may be present in the form of an acid anhydride group) or R ₅ (OH) OPO A group (R ₅ is a hydroxyl group, an alkoxy group or an aryloxyl group);
An integer, l is an integer of 1 or 2, m is an integer of 0 or 1,
p + 1 = 2 to 4].

In the above formula, the group represented by R ₃ is a hydrogen atom or an alkyl group, and specific examples of the alkyl group include a methyl group and an ethyl group.

R ₄ is a divalent to tetravalent organic residue having 2 to 20 carbon atoms whose main chain may be interrupted by oxygen. When the number of carbon atoms is 1 or less, the adhesion durability under wet conditions is low. When the number of carbon atoms is 21 or more, it is difficult to obtain a material and the strength of the cured product cannot be obtained, so that the adhesive strength is low. The organic residue may be an aliphatic or aromatic organic residue as long as the number of carbon atoms is satisfied, and may be partially substituted with a substituent such as a halogen, an amino group, a hydroxyl group, or the like.

In the general formula, Y is a carboxyl group or R
₅ (OH) OPO- group, wherein 1 or 2
Are united. Here group represented by R ₅ is hydroxyl; is either a phenoxy group, aryloxyl group such as a benzyloxy group; methoxy group, an ethoxy group, an alkoxyl group or butoxy group.

Specific examples of commonly used acidic group-containing monomers are given below.

[0018]

Embedded image

A monomer having one carboxyl group in the molecule;

[0020]

Embedded image

A monomer having two carboxyl groups in the molecule;

[0022]

Embedded image

A monomer having one phosphate group in the molecule;

[0024]

Embedded image

And the like. Monomers having two phosphate groups in the molecule.

In order for the curable composition of the present invention to exhibit excellent adhesiveness among the above acidic group-containing monomers, it is necessary to use 7-methacryloxy-1,1-heptanedicarboxylic acid, 11-methacryloxy-1,1 -Undecanedicarboxylic acid, 13
Dicarboxylic acids having two carboxyl groups in the molecule, such as -methacryloxy-1,1-tridecanedicarboxylic acid, are particularly preferred.

The acidic group-containing monomer is usually used in an amount of 1 to 50 per 100 parts by weight of the total polymerizable monomer in the photocurable composition.
It is contained by weight.

Another component of the photocurable composition of the present invention is a photosensitizer. As the photosensitizer, known photosensitizers used for ultraviolet light or visible light can be used without particular limitation.

Specific examples include diacetyl, acetylbenzoyl, benzyl, 2,3-pentadione,
3-octadione, 4,4'-dimethoxybenzyl, α
-Naphthyl β-naphthyl, 4,4′-oxybenzyl,
Camphorquinone, 9,10-phenanthrenequinone,
Α-diketones such as acenaphthenequinone; benzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin propyl ether;
Thioxanthone derivatives such as 4-diethoxythioxanthone, 2-chlorothioxanthone and methylthioxanthone; benzophenone derivatives such as benzophenone, P, P'-dimethylaminobenzophenone and P, P'-methoxybenzophenone are preferably used.

Particularly preferred are α-diketones,
Among them, camphorquinone is preferred.

The above-mentioned photosensitizers can be used not only alone, but also in combination of two or more as required.

These photosensitizers are used in an amount of 0.05 to 10 parts by weight based on 100 parts by weight of all polymerizable monomers in the photocurable composition.
It is desirable to add 0.1 parts by weight, preferably 0.1 to 5 parts by weight.

Still other components of the photocurable composition of the present invention have the following general formula:

[0034]

Embedded image

A polymerization accelerator comprising an aminobenzene compound represented by the following formula:

[0036] In the general formula, R ₁ is an alkyl group such as a methyl group, an ethyl group, a propyl group, X ₁ and X
₂ is a hydroxyl group, a CH ₂ ＣＨCHCOO— group, or a CH ₂ ＣC
(CH ₃ ) COO— group. However, compounds in which both X ₁ and X ₂ are hydroxyl groups are excluded because the effects of the present invention are not exhibited.

Specific examples of the above-mentioned aminobenzene compounds include the following.

[0038]

Embedded image

Such a polymerization accelerator is usually used in an amount of 0.05 to 10 per 100 parts by weight of all polymerizable monomers in the photocurable composition.
It is desirable to add 0.1 parts by weight, preferably 0.1 to 5 parts by weight.

Further, a polymerization inhibitor, a colorant, an ultraviolet absorber and the like can be added to the photocurable composition of the present invention, if desired. In addition, when used for applications such as a filling material for caries cavity repair, a filling material is generally added.

Examples of the filler include an inorganic filler and an organic filler. Specific examples of the former include quartz powder, alumina powder, hydroxyapatite, calcium carbonate, fluoroaluminosilicate glass, barium sulfate, and titanium oxide. , Zirconia powder, ultrafine silica, spherical silica,
Examples include spherical silica-titania, spherical silica-zirconia, amorphous silica-titania, amorphous silica-zirconia, and the like. Examples of the latter include polymethyl methacrylate powder and polyethyl methacrylate powder.

The photocurable composition of the present invention is finally used by mixing all the components. However, in order to prevent deterioration during storage, the composition may be divided into two stable packages as necessary. it can. For example, a package (A) comprising an acidic group-containing monomer, a part of a (meth) acrylate monomer and a photosensitizer, and a polymerization accelerator and a part of a (meth) acrylate monomer Combination of packaging (B) is common

[0043]

According to the photocurable composition of the present invention, the unpolymerized monomer after curing is reduced by using a specific polymerization accelerator, and therefore, the dynamic properties such as compressive strength, tensile strength and abrasion resistance are improved. A cured product having excellent physical properties can be obtained. Further, when the amount of the unpolymerized monomer is small, since the residual monomer is less irritating to the pulp and the like, it is particularly useful as a dental restorative filling material or adhesive used in the oral cavity.

[0044]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

The (meth) acrylate monomers, acidic group-containing monomers, photosensitizers, polymerization accelerators and polymerization inhibitors used in the examples are abbreviated as follows.

11-methacryloxy-1,1-undecanedicarboxylic acid; 11-MUDCA 2-methacryloxyethyl succinic acid; 2-MEC 6-methacryloxyhexyl phosphate; 6-MHP bisphenol A diglycidyl methacrylate; Bis
GMA Triethylene glycol dimethacrylate; TEGDM
A 2-hydroxyethyl methacrylate; HEMA neopentyl glycol dimethacrylate; NPG camphorquinone; CQN, N-di (β-hydroxyethyl) -P-toluidine; DHEPT dimethylaminoethyl methacrylate; DMAEM hydroquinone monomethyl ether; HQME

[0047]

Embedded image

Examples 1 to 4 and Comparative Example 1 A predetermined amount of the following composition was divided into mortars, and then kneaded to prepare a paste-like photocurable composition. The types and amounts of the photosensitizer and the polymerization accelerator used in each Example and Comparative Example are as shown in Table 1.

[Composition] Bisphenol A diglycidyl methacrylate 15 parts by weight Triethylene glycol dimethacrylate 10 parts by weight Photosensitizer x parts by weight Polymerization promoter y parts by weight Hydroquinone monomethyl ether 0.05 parts by weight Spherical silica zirconia 75 parts by weight ( (Average particle diameter: 0.2 μm, silane treated) Various physical properties of the prepared photocurable composition were measured according to the methods described below.

(1) Surface Hardness The paste of the photocurable composition was charged into a stainless steel split mold having a hole having a diameter of 6 mm and a depth of 3 mm, and pressed with a polypropylene film. Next, the tip of a quartz rod of a visible light irradiator White Light (trade name, manufactured by Takara Labelmont Co., Ltd.) was fixed to the pressure contact surface, and light irradiation was performed for 60 seconds. After irradiation,
Remove the cured polymer from the mold and place it in distilled water at 37 ° C.
It was immersed and stored for 4 hours. After storage, the surface hardness of the irradiated surface was measured using a Micro Brinell hardness tester manufactured by Mori Test Machine. Compressive strength: The paste was charged into a stainless steel split mold having a hole of 4 mm in diameter and 3 mm in depth, and pressed with a polypropylene film. Next, the tip of the quartz rod of white light was fixed to the pressure contact surface, and light irradiation was performed for 30 seconds. After irradiation, the polymer cured product is removed from the mold, and 30
Irradiated for 2 seconds. Next, the cured product was immersed and stored in distilled water at 37 ° C. for 24 hours.
The compressive strength was measured using 0D. The crosshead speed was 10 mm / min.

(2) Tensile Strength The paste was filled into a stainless steel split mold having a hole having a diameter of 6 mm and a depth of 3 mm, and pressed with a polypropylene film. Next, the tip of the quartz rod of white light was fixed to the pressure contact surface, and light irradiation was performed for 30 seconds. After the irradiation, the cured polymer was removed from the mold, and the bottom of the cured product was irradiated with light for 30 seconds. Next, the cured product was immersed and stored in distilled water at 37 ° C. for 24 hours, and then the tensile strength was measured using Shimadzu Autograph AG5000D. The crosshead speed was 10 mm / min.

(3) Toothbrush abrasion depth Similarly, paste is 10 mm long, 10 mm wide and 1.5 depth deep.
It was charged into a Teflon mold having a hole of mm, and pressed with a polypropylene film. Next, the quartz rod end of a visible light irradiator white light was fixed to the pressure contact surface, and light irradiation was performed for 60 seconds. After the irradiation, the cured polymer was removed from the mold and immersed and stored in distilled water at 37 ° C. for 7 days.
The polymerization hardener was abraded 1500 mm with a toothbrush under a load of 400 g. The wear depth was determined by testing the wear weight by the density of the cured polymer.

(4) Discoloration by Dye Similarly, the paste was charged into a stainless steel split mold having a hole having a diameter of 6 mm and a depth of 3 mm, and pressed with a polypropylene film. Next, the tip of the quartz rod of white light was fixed to the pressure contact surface, and light irradiation was performed for 30 seconds.

Next, the cured product was placed in distilled water at 37 ° C. for 24 hours.
After immersion storage for a period of time, the irradiated surface is
The cured product is immersed in an aqueous coffee solution containing 8% of instant coffee powder (Nescafe, Nestle Japan) and polished with 3M), and the color tone change after 24 hours is measured. The color tone change amount is represented by a difference ΔE between the color tone before immersion in the coffee aqueous solution and the color tone after immersion in the coffee aqueous solution for 24 hours. Here, ΔE is ΔE (L. ab) proposed by Hunter.

For measurement of the cured product, a colorimeter TC-1800MKII manufactured by Tokyo Denshoku Co., Ltd. was used.

The results obtained are shown in Table 1.

[0057]

[Table 1]

Examples 5 to 8, Comparative Example 2 The paste composed of the photocurable composition used in Examples 1 to 4 and Comparative Example 1 was charged into a stainless steel split mold having a hole of 6 mm in diameter and 3 mm in depth. Then, they were pressed with a polypropylene film. Next, the tip of the quartz rod of white light was fixed to the pressure contact surface, and light irradiation was performed for 30 seconds. After the irradiation, the cured polymer was removed from the mold, and the bottom of the cured product was irradiated with light for 30 seconds. Then, the cured body was immersed in ethanol 10 minutes after the irradiation was completed, and one week later, the dissolved amount of the residual monomer and the catalyst component was determined from the weight change.

[0059]

[Table 2]

Examples 9 to 11 and Comparative Examples 3 to 4 Using photocurable compositions of various compositions shown in Table 3 as an adhesive, the adhesive strength to dentin was measured. The measuring method is as follows.

The bovine anterior teeth were removed within 24 hours after the slaughter, and dentin was cut out under water by using # 800 emery paper so as to be horizontal to the lips. Next, after blowing compressed air on the surface for about 10 seconds and drying, a paraffin wax with a hole of 4 mm in diameter is fixed to the dentin surface with a double-sided tape to form a simulated cavity having the surface as the bottom surface. did. The surface was dried by blowing compressed air, followed by application of a paste-like photocurable composition obtained by mixing the components shown in Table 3 by a passing method, and then applying a commercially available visible light irradiator Whitelight. And irradiated with light for 10 seconds. Further, a commercially available light-curable composite resin "PARFIQUE ESTELLITE" (manufactured by Tokuyama Soda Co., Ltd.) was loaded thereon, pressed, and then irradiated again with light for 30 seconds to cure.

After the composite resin was cured, the paraffin wax was removed and the composite resin was left in water at 37 ° C. for 24 hours. Next, metal attachments were attached to the cow front teeth and the cured composite resin, respectively, and the adhesion strength between the dentin and the photocurable composition was measured by a tensile tester (crosshead speed: 10 mm / min).

[0063]

[Table 3]

Claims (1)

(57) [Claims] (A) a (meth) acrylate monomer,
It comprises (b) a photosensitizer and (c) a polymerization accelerator, and (c) the polymerization accelerator has the following general formula: In the formula, R ₁ is a lower alkyl group, X ₁ and X ₂ are a hydroxyl group or a CH ₂ ＣC (R ₂ ) COO— group (R ₂ represents a hydrogen atom or a methyl group), provided that X _1. A photo-curable composition characterized by being an aminobenzene compound represented by｝ except when both X ₂ are hydroxyl groups.