JPH07165808A - Photo-setting composition - Google Patents

Abstract

PURPOSE:To obtain a composition which is almost free from an unpolymerized monomer after curing and is useful particularly for dental application by incorporating a photosensitizer and a polymerization accelerator comprising a specified aminobenzene compound into a (meth)acrylate monomer. CONSTITUTION:A (meth)acrylate monomer, such as bisphenol A diglycidyl methacrylate or triethylene glycol dimethacrylate, is mixed with a photosensitizer comprising, e.g. camphorquinone and a polymerization accelerator which comprises a dialkylaminobenzene compound substituted by an unsaturated carboxylic acid ester and represented by the formula [wherein R1 is lower alkyl; and X1 and X2 are each hydroxyl or CH2=CR2-CO2 (wherein R2 is H or methyl) except for the case where of them are hydroxyl at the same time] to give a photo-setting composition. The incorporation of the polymerization accelerator into the composition reduces the polymerization hindrance due to oxygen or a monomer containing an acidic group, makes the composition almost free from an unpolymerized monomer after curing, and gives a cured material excellent in mechanical properties. The amount of the polymerization accelerator to be added is 0.05-10 pts.wt., preferably 0.1-5 pts.wt., based on 100 pts.wt. polymerizable monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocurable composition containing a small amount of residual monomers, catalysts and other eluates from a polymerized and cured product.

[0002]

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

[0003]

The above photocurable composition is liable to contain an amine compound which is a polymerization accelerator because its polymerization activity is easily inhibited by the acid group-containing monomer used for imparting adhesiveness and oxygen. It was necessary to use a large amount, and as a result, the surface hardness after curing became insufficient and the adhesive strength decreased when used as an adhesive due to an increase in unpolymerized monomer in the deep part. .

[0004]

Means for Solving the Problems The present inventors have conducted various studies to solve the defects of the photopolymerization initiator composed of a photosensitizer and an amine compound as described above, and as a result, have a specific structure. It was found that a photocurable composition having high sensitivity with less polymerization inhibition by an acid group-containing monomer and oxygen can be obtained by using an aminobenzene compound, and completed the present invention.

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

[0006]

[Chemical 2]

{In the formula, R ₁ is a lower alkyl group, and X is
₁ and X ₂ are a hydroxyl group, or CH ₂ ═C (R ₂ ) COO-
A photocurable composition, which is an aminobenzene compound represented by a group [R ₂ represents a hydrogen atom or a methyl group, except when both X ₁ and X ₂ are hydroxyl groups]. Is.

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

Specific examples of the (meth) acrylate-based monomers that are generally preferably used include methyl (meth) acrylate.
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) acrylates 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-based monomers; ethylene glycol di (meth) acrylate, dietine 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,
2'-bis [4- (3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane, trimethylolpropane (meth) acrylate, trimethylolethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, etc. A functional (meth) acrylate-based 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 (meth) acrylate-based monomer. It is preferable to mix them with.

Preferred examples of the acidic group-containing monomer include the following general formula

[0012]

[Chemical 3]

[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 1 = 2, Y may be present in the form of an acid anhydride group) or R ₅ (OH) OPO -Group (R ₅ is a hydroxyl group, an alkoxy group or an aryloxyl group), p is 1 to 3
Is an integer, 1 is an integer of 1 or 2, m is an integer of 0 or 1,
and p + l = 2-4].

In the above general 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, the main chain of which may be interrupted by oxygen. When the carbon number is 1 or less, the adhesion durability under wet condition is low. When the carbon number is 21 or more, it is difficult to obtain the material, and the strength of the cured product cannot be obtained, and the adhesive force is low. The organic residue may be either an aliphatic organic residue or an aromatic organic residue as long as the carbon number is satisfied, and may be partially substituted with a substituent such as a halogen, an amino group or a hydroxyl group.

In the general formula, Y is a carboxyl group or R
₅ (OH) OPO- group, 1 or 2 in the above organic residue
Individually combined. Here, the group represented by R ₅ is any of a hydroxyl group; an alkoxyl group such as a methoxy group, an ethoxy group and a butoxy group; and an aryloxyl group such as a phenoxy group and a benzyloxy group.

Specific examples of those generally used as the acidic group-containing monomer are specifically shown below.

[0018]

[Chemical 4]

A monomer having one carboxyl group in the molecule such as

[0020]

[Chemical 5]

A monomer having two carboxyl groups in the molecule such as

[0022]

[Chemical 6]

A monomer having one phosphate group in the molecule such as;

[0024]

[Chemical 7]

Monomers having two phosphoric acid groups in the molecule such as

Among the above-mentioned acidic group-containing monomers, 7-methacryloxy-1,1-heptanedicarboxylic acid and 11-methacryloxy-1,1 are used to develop excellent adhesiveness to the curable composition of the present invention. -Undecane dicarboxylic acid, 13
-Dicarboxylic acids having two carboxyl groups in the molecule such as methacryloxy-1,1-tridecanedicarboxylic acid are particularly preferable.

Such an acidic group-containing monomer is usually used in an amount of 1 to 50 per 100 parts by weight of all the polymerizable monomers in the photocurable composition.
Includes parts by weight.

The other component of the photocurable composition of the present invention is a photosensitizer. As the photosensitizer, known ones used for ultraviolet rays or visible rays can be used without particular limitation.

Specific examples include diacetyl, acetylbenzoyl, benzyl, 2,3-pentadione, 2,
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, benzoin propyl ether; 2,
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 is the α-diketone,
Among them, camphor quinone is preferable.

The above-mentioned photosensitizers can be used not only individually, but also as a combination of a plurality of types if necessary.

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

The other component of the photocurable composition of the present invention is represented by the following general formula:

[0034]

[Chemical 8]

It is a polymerization accelerator composed of an aminobenzene compound represented by:

In the above general formula, R ₁ is an alkyl group such as a methyl group, an ethyl group or a propyl group, and X ₁ and X
₂ hydroxyl groups, CH ₂ = CHCOO- group, or CH ₂ = C
It is a (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 compound include the following.

[0038]

[Chemical 9]

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

If desired, a polymerization inhibitor, a colorant, an ultraviolet absorber, etc. may be added to the photocurable composition of the present invention. Further, when it is used as a filling material for repairing a caries cavity, it is generally added with a filling material.

As the filler, there are 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 thereof include spherical silica-titania, spherical silica-zirconia, amorphous silica-titania, and amorphous silica-zirconia. Examples of the latter include polymethylmethacrylate powder and polyethylmethacrylate powder.

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

[0043]

EFFECTS OF THE INVENTION The photocurable composition of the present invention contains a small amount of unpolymerized monomer after curing due to the use of a specific polymerization accelerator. Therefore, the mechanical properties such as compressive strength, tensile strength and abrasion resistance are improved. A cured product having excellent physical properties can be obtained. In addition, when the amount of unpolymerized monomer is small, the residual monomer causes less irritation to the pulp and the like, and thus it is particularly useful as a dental restoration filling material or adhesive used in the oral cavity.

[0044]

EXAMPLES Examples will be shown below to more specifically describe the present invention, but the present invention is not limited to these examples.

The (meth) acrylate-based monomer, acidic group-containing monomer, photosensitizer, polymerization accelerator and polymerization inhibitor 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
A2-hydroxyethyl methacrylate; HEMA neopentyl glycol dimethacrylate; NPG camphorquinone; CQ N, N-di (β-hydroxyethyl) -P-toluidine; DHEPT dimethylaminoethyl methacrylate; DMAEM hydroquinone monomethyl ether; HQME

[0047]

[Chemical 10]

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

[Composition] Bisphenol A diglycidyl methacrylate 15 parts by weight Triethylene glycol dimethacrylate 10 parts by weight Photosensitizer x parts by weight Polymerization accelerator y parts by weight Hydroquinone monomethyl ether 0.05 parts by weight Spherical silica zirconia 75 parts by weight ( Average particle size 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 filled in 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 a visible light irradiator White Light (trade name, manufactured by Takara Belmont Co., Ltd.) was fixed to the pressing surface and light irradiation was performed for 60 seconds. After irradiation,
Remove the cured polymer from the split mold and place it in distilled water at 37 ° C for 2
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 Tester. Compressive strength: The paste was filled in a stainless split mold having a hole with a diameter of 4 mm and a depth of 3 mm, and pressed with a polypropylene film. Next, the tip of a quartz rod of white light was fixed to the pressing surface and light irradiation was performed for 30 seconds. After irradiation, remove the cured polymer from the split mold,
Illuminated for a second. Next, the cured product was immersed and stored in distilled water at 37 ° C. for 24 hours, and then Shimadzu Autograph AG500
Compressive strength was measured using OD. The crosshead speed was 10 mm / min.

(2) Tensile Strength The paste was filled in 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 split mold, and the bottom surface of the cured product was further 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 wear depth Similarly, paste is 10 mm in length, 10 mm in width, and 1.5 in depth.
It was filled in a Teflon mold having holes of mm and pressed with a polypropylene film. Next, the tip of the quartz rod of the white light irradiator, a visible light irradiator, was fixed to the pressing surface and light irradiation was performed for 60 seconds. After irradiation, the cured polymer was removed from the mold and immersed in distilled water at 37 ° C for 7 days for storage.
The polymerization curing agent 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 polymerized cured product.

(4) Discoloration by Dye Similarly, the paste was filled in 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.

Then, the cured product was placed in distilled water at 37 ° C. for 24 hours.
After soaking and storing for a period of time, the irradiated surface is Soplex (trade name:
The hardened material is immersed in an aqueous coffee solution containing 8% of instant coffee powder (Nescafe, Nestle Japan) after polishing with 3M) and the change in color tone after 24 hours is measured. The color tone change amount is represented by a difference ΔE between the color tone before the immersion in the coffee aqueous solution and the color tone after the immersion in the coffee aqueous solution for 24 hours. Here, ΔE is ΔE (Lab) proposed by Hunter.

A colorimetric color difference meter TC-1800MKII type manufactured by Tokyo Denshoku Co., Ltd. was used for the measurement of the cured product.

The results obtained are also shown in Table 1.

[0057]

[Table 1]

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

[0059]

[Table 2]

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

The bovine anterior teeth were extracted within 24 hours after the slaughter, and the dentin was carved out with water of # 800 emery paper so as to be horizontal to the labial surface. Next, compressed air is blown to the surface for about 10 seconds and dried, and then paraffin wax with a hole of 4 mmφ in diameter is fixed to the surface of this dentin with double-sided tape to form a simulated cavity with the surface as the bottom surface. did. Compressed air was blown to the surface to dry, and then the paste-like photocurable composition obtained by mixing the components shown in Table 3 by a conventional method was applied, and then a commercially available visible light irradiator White Light was applied. It was irradiated with light for 10 seconds. Further, a commercially available photocurable composite resin "Palfique Esterite" (manufactured by Tokuyama Soda Co., Ltd.) was filled therein, pressed, and then again irradiated with light for 30 seconds to be cured.

After the composite resin was cured, the paraffin wax was removed, and the composite resin was allowed to stand in water at 37 ° C. for 24 hours. Next, metal attachments were attached to the bovine anterior teeth and the cured composite resin, 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)

[Claims] 1. (a) (meth) acrylate-based monomer,
(B) a photosensitizer and (c) a polymerization accelerator are contained, and (c) the polymerization accelerator is represented by the following general formula: [Wherein, R ₁ is a lower alkyl group, X ₁ and X ₂ are a hydroxyl group, or CH ₂ ═C (R ₂ ) COO-group [R ₂ represents a hydrogen atom or a methyl group], provided that X _{1. A} photocurable composition, characterized in that it is an aminobenzene compound represented by the formula ₁ , wherein X and X ₂ are both hydroxyl groups.