JPH0662687B2 - Photocurable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is excellent in photocurability in a low temperature region near room temperature, and is excellent in hardness, strength, abrasivity, surface gloss, abrasion resistance, color tone and the like of a cured product. It relates to an excellent photocurable composition. More specifically, it relates to a composite material for teeth, a photocurable composition capable of exhibiting excellent properties as a curable composition for teeth.

Conventionally, as curable compositions for teeth such as composite resin and hard resin, many curable compositions comprising a radical polymerizable monomer such as a (meth) acrylate vinyl monomer and a polymerization initiator have been proposed. There is.

Further, as the performance required for the tooth composite resin and the tooth hard resin, in addition to the excellent curing performance in the low temperature region around room temperature of the composition, the strength, compression strength, hardness and wear resistance of the cured product It is required to have excellent mechanical properties such as properties and color tone. With the recent remarkable progress in the dental restorative treatment technology, the demand for the above-mentioned performance improvement of these hardened tooth compositions has become remarkably severe.

Among the curable compositions for teeth, which are composed of a radical polymerizable monomer such as a conventional (meth) acrylic acid vinyl monomer and a polymerization initiator, a photopolymerization initiator is used as a polymerization initiator and photocured. There are some proposals that attempt to achieve the above-mentioned performance improvement by adopting the method. For example, JP-B-54-10986, JP-B-55-33687, and JP-A-56
-120610, JP-A-57-54107,
A photo-curable composition has been proposed in JP-A-57-120506. Further, in these prior art documents,
A method has also been proposed in which a filler such as silica is added to the curable composition in order to improve mechanical properties such as hardness, strength and abrasion resistance of the cured product. However, when these photocurable compositions are used for dental photocurable compositions such as composite resin and hard resin, mechanical properties such as strength, hardness and abrasion resistance are not sufficient. Further, there are drawbacks such as poor polishing property, particularly poor surface smoothness and surface gloss after polishing treatment, and insufficient abrasion resistance.

[Problems to be solved by the invention]

Therefore, in the field of photocurable compositions for teeth such as composite resin and hard resin, the above-mentioned drawbacks of conventional photocurable compositions have been improved and mechanical properties such as strength, hardness and wear resistance of cured products have been improved. There is a strong demand for a photocurable composition having excellent physical properties and good abrasiveness, and particularly excellent in surface smoothness after polishing, surface gloss and abrasion resistance.

The present inventors have considered that the conventional photocurable composition, especially the photocurable composition for teeth and the performance requirements for the composition are in the above-mentioned situations, and thus curing of the photocurable composition. As a result of searching for a photocurable composition having excellent performance, mechanical properties of a cured product and excellent abrasiveness, a photocurable composition comprising a radical polymerizable monomer, a specific composite filler and a photopolymerization initiator. Have found that the above objects can be achieved, and have reached the present invention.

〔The invention's effect〕

The photocurable composition of the present invention has a high photocuring rate in a low temperature region near room temperature, excellent mechanical properties such as strength, compressive strength, and hardness of the cured product, and color tone, and further excellent abrasiveness of the cured product. , Excellent in surface smoothness after polishing, surface gloss and abrasion resistance, and for composite teeth resin for teeth,
Since it sufficiently satisfies the performance required for a tooth curable composition such as a hard resin, it is suitable not only for these tooth applications but also for various precision machining other than tooth applications. It can also be used for such purposes.

[Means for Solving Problems] and [Action] According to the present invention, (A) a radical-polymerizable monomer, (B) a surface of a fine-particle inorganic filler is coated with a radical-polymerizable polyfunctional (meth) acrylate. There is provided a photocurable composition comprising a composite filler polymerized and coated with a base monomer, and (C) a photopolymerization initiator.

The radical-polymerizable monomer (A) used in the photocurable composition of the present invention is a usual radical-polymerizable carbon / carbon unsaturated monomer, and more specifically, unsaturated carboxylic acid monomer Body, ester unsaturated monomer, nitrile unsaturated monomer, aromatic vinyl compound and the like.
Examples of the unsaturated carboxylic acid monomer include acrylic acid and methacrylic acid, and examples of the ester unsaturated monomer include (meth) acrylic acid ester-based monomers, vinyl acetate, acetic acid. Examples thereof include lower aliphatic carboxylic acid unsaturated ester monomers such as allyl. Examples of the nitrile unsaturated monomer include acrylonitrile and methacrylonitrile, and examples of the aromatic vinyl compound include styrene, α-methylstyrene, vinyltoluene, and isopropenyltoluene. it can.

More specifically, the (meth) acrylic acid ester-based monomer is a (meth) acrylic acid ester-based compound formed from acrylic acid or methacrylic acid and a monovalent hydroxyl compound or a polyvalent hydroxyl compound. More specifically, alkyl (meth) acrylates such as methyl (meth) acrylate and ethyl (meth) acrylate,
2-Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) Acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate,
Butylene glycol di (meth) acrylate, hexylene glycol di (meth) acrylate, 2,2-bis [4
-(Meth) acryloyloxyphenyl] propane, 2,
2-bis [4- (meth) acryloyloxycyclohexyl] propane, 2,2-bis [3- (meth) acryloyloxy-2-hydroxypropoxyphenyl] propane, 1,2-di (meth) acryloyloxyethoxybenzene , 1,3-di (meth) acryloyloxyethoxybenzene, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2,2,4 (2,4, 4) -Trimethylhexamethylene diisocyanate (1 mol) and 2-hydroxyethyl (meth) acrylate (2 mol) can be exemplified. Among these radical-polymerizable monomers, a radical-polymerizable polyfunctional (meth) acrylate-based monomer having at least two (meth) acryloyloxyl groups in one molecule or the radical-polymerizable polyfunctional A radically polymerizable monomer mixture containing a polymerizable (meth) acrylate-based monomer as a main component is particularly preferable. The radical polymerizable polyfunctional (meth)
As the acrylate-based monomer, triethylene glycol di (meth) acrylate, 1,3-di (meth) acryloyloxyethoxybenzene, 2,2,4 (2,4,4) -trimethylhexamethylenediamine diisocyanate 1 mole and 2
It is preferable to use a mixture of two or more adducts of 2 mol of hydroxyethyl (meth) acrylate, especially a mixture of three.

Composite filler (B) blended in the photocurable composition of the present invention
Is a composite filler obtained by polymerizing and coating the surface of the fine particle inorganic filler with a radically polymerizable polyfunctional (meth) acrylate-based monomer. Specific examples of the fine particle inorganic filler constituting the composite filler (B) include silica, silica-alumina,
Examples thereof include fine particle powders of alumina, quartz, glass, calcium carbonate, clay, mica, aluminum sulfate, barium sulfate, calcium sulfate, and the like, and the average particle size thereof is usually 0.1 mμ to 100 μm, preferably 1 μm.
It is in the range of mμ to 50μ. The surface of the fine particle inorganic filler constituting the composite filler is surface-treated with a silane-based capping agent or a titanate-based capping agent before being polymerized and coated with the radical-polymerizable polyfunctional acrylate-based monomer. May be.

The radical-polymerizable polyfunctional (meth) acrylate-based monomer used for the polymerization coating treatment of the surface of the fine-particle inorganic filler is a radical-polymerizable polyfunctional monomer in the radical-polymerizable monomer (A). The (meth) acrylate-based monomer can be similarly exemplified, and one kind or a mixture of two or more kinds thereof can be applied. Among the radical-polymerizable polyfunctional (meth) acrylate-based monomer components, radical-polymerizable monomers having 3 or more (meth) acryloyloxyl groups in one molecule, or 3 or more in one molecule Radical-polymerizable polyfunctional (meth) acrylate-based monomer having (meth) acryloyloxyl group and radical-polymerizable polyfunctional (meth) acrylate-based monomer having two (meth) acryloyloxyl groups in one molecule A mixed component with a monomer is preferable, and the composition of the latter mixed component has a radical-polymerizable polyfunctional (meth) acrylate having three or more (meth) acryloyloxyl groups in one molecule. The amount of the system monomer is usually 25% by weight or more, preferably 45% by weight or more. Radical-polymerizable polyfunctional (meth) acrylate-based monomers having three or more (meth) acryloyloxyl groups in one molecule include trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dimethacrylate. It is preferably pentaerythritol hexa (meth) acrylate.

The ratio of the radical-polymerizable polyfunctional (meth) acrylate monomer component polymerized and coated on the surface of the composite filler is usually 30 to 200 parts by weight with respect to 100 parts by weight of the fine particle inorganic filler. Parts, preferably 50 to 150
The range is parts by weight. The average particle diameter of the composite filler is usually in the range of 1 mμ to 100 μ, preferably 10 mμ to 50 μ.

As a method for producing the composite filler, for example, a method in which a fine particle inorganic filler powder and a radical-polymerizable polyfunctional (meth) acrylate-based monomer are mixed in advance and then radical-polymerized is preferable. In this pre-mixing, a small amount of both pastes are mixed to form a slightly hard paste, and the paste is applied to a two-roll roll, Banbury mixer, ball mill, etc., and while kneading, the remaining fine-particle inorganic filler powder and radical-polymerizable polyfunctional (meth) are mixed. ) An acrylate monomer and a radical polymerization initiator are sequentially mixed. The mixing ratio thereof is generally within the range of 30 to 200 parts by weight of the radical-polymerizable polyfunctional (meth) acrylate-based monomer with respect to 100 parts by weight of the fine particle inorganic filler powder component. As the radical polymerization initiator, dicumyl peroxide, benzoyl peroxide, azobisisobutyronitrile or the like is used in an amount of about 0.01 to 3 based on the weight of the radical polymerizable polyfunctional (meth) acrylate monomer. It is used in an amount of about wt%.

The mixture consisting of these components is heated to about 40 to 250 ° C., preferably about 60 to 15 by using a hot press or the like.
Polymerization is carried out by heating at a temperature of 0 ° C. and under conditions of about 1 to 300 kgG / cm ² , preferably about 10 to 200 kgG / cm ² for about several minutes to one hour. It is also possible to polymerize by heating in an inert gas atmosphere without applying pressure. In any case, it is preferable to stop the polymerization reaction under the condition that a part of the polymerizable double bond in the acrylic monomer remains as it is. The obtained cured product is crushed to a desired size using, for example, a ball mill.

The photopolymerization initiator (C) blended in the photocurable composition of the present invention comprises an α-ketocarbonyl compound (C ₁ ) and an amine or an aromatic nitrogen-containing condensed ring compound (C ₂ ). Examples of the α-ketocarbonyl compound include α-diketone, α-ketoaldehyde, α-ketocarboxylic acid and α-ketocarboxylic acid.
Examples thereof include ketocarboxylic acid ester.
More specifically, diacetyl, 2,3-pentadione,
2,3-hexadione, benzyl, 4,4'-dimethoxybenzyl, 4,4'-diethoxybenzyl, 4,4'-oxybenzyl, 4,4'-dichlorobenzyl, 4-nitrobenzyl, α-naphthyl , Β-naphthyl, camphorquinone,
Α-diketones such as 1,2-cyclohexanedione, α-diketones such as methylglyoxal and phenylglyoxal
Examples thereof include ketoaldehyde pyruvic acid, benzoylformic acid, phenylpyruvic acid, methyl pyruvate, ethyl benzoylformate, methyl phenylpyruvate, and butyl phenylpyruvate. Among these α-ketocarbonyl compounds, α-diketones are preferably used in terms of stability and the like. Among the α-diketones, diacetyl, benzyl and camphorquinone are preferable.

The amine compounded as one component of the photopolymerization initiator in the photocurable composition of the present invention may be either an aliphatic amine or an aromatic amine, but an aromatic amine is preferred.
Particularly suitable aromatic amines have the general formula [I] [In the formula, R ¹ represents a hydrogen atom, an alkyl group or a hydroxyalkyl group, R ² represents a hydrogen atom, an alkyl group, a hydroxyalkyl group or an aryl group, R ³ represents an acyl group, a carboxyl group, an alkoxycarbonyl group, A substituted aromatic amine represented by a hydroxyacyl group, a carbamoyl group which may have a substituent, a cyano group, a nitro group, or a halogen atom]. Specific examples of the substituted aromatic amine include 4-dimethylaminobenzaldehyde, 4-diethylaminobenzaldehyde, 4- (methylhexylamino) benzaldehyde, 4- (methylphenylamino) benzaldehyde and 4- (β-hydroxyethylmethylamino). ) Benzaldehyde, 4-dimethylaminobenzoic acid, 4-diethylaminobenzoic acid, 4-
(Methylhexylamino) benzoic acid, 4- (methylphenylamino) benzoic acid, 4- (β-hydroxyethylamino) benzoic acid, methyl 4-dimethylaminobenzoate,
Methyl 4-diethylaminobenzoate, methyl 4-dipropylaminobenzoate, methyl 4- (methylhexylamino) benzoate, methyl 4 (methylphenylamino) benzoate, 4- (β-hydroxyethylmethylamino) benzoic acid Propyl, hexyl 4-dimethylaminobenzoate,
Phenyl 4-dimethylaminobenzoate, 4-dimethylaminophthalic acid, 4-dimethylaminophthalic acid, dimethyl 4-dimethylaminoisophthalate, N, N-dimethyl-o
-Cyanoaniline, N, N-dimethyl-o-nitroaniline, N, N-dimethyl-o-chloroaniline, N, N-dimethyl-o-bromoaniline, N, N-dimethyl-o-iodoaniline, N, N-dimethyl-m-cyanoaniline, N, N-
Dimethyl-m-nitroaniline, N, N-dimethyl-m-
Chloraniline, N, N-dimethyl-m-bromoaniline, N, N-dimethyl-p-cyanoaniline, N, N-dimethyl-p-nitroaniline, N, N-dimethyl-p-chloroaniline, N, N -Dimethyl-p-bromoaniline, N, N-
Diethyl-o-cyanoaniline, N, N-diethyl-m-
Cyanoaniline, N, N-diethyl-p-cyanoaniline, N, N-diethyl-p-chloroaniline, N, N-dipropyl-p-cyanoaniline, N, N-dibutyl-p-cyanoaniline, N, N -Methylphenyl-p-cyanoaniline, N, N-β-hydroxyethylmethyl-p-chloroaniline, N, N-dimethyl-2,4-dicyanoaniline, N, N
-Dimethyl-2,4-dinitroaniline, N, N-dimethyl-
2,4-dichloroaniline and the like can be exemplified.
Among these substituted aromatic amines, 4-dialkylaminobenzaldehyde, 4-dialkylaminobenzoic acid, 4-dialkylaminobenzoic acid ester and N, N-dialkyl-p-cyanoaniline are preferable, and 4-diethylaminobenzoic acid is preferable. Particularly preferred.

Further, as the aromatic nitrogen-containing condensed ring compound to be blended as one component of the photopolymerization initiator in the photocurable composition of the present invention, a compound represented by the general formula [II] [In the formula, X represents> NR ² , an oxygen atom or a sulfur atom,
Y represents a hydrogen atom, -SR ³ or 1 to trivalent metal, R ¹ is an alkyl group, an aryl group, an aralkyl group, a halogen atom, n represents an integer of 0 to 4, n is 2 or more In some cases, R ¹ may be different groups, R ^1
2 represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and R ³ represents an alkyl group, an aryl group or the general formula [III]. (In the formula, X, R ¹ and n are the same as the above), which is an aromatic nitrogen-containing condensed ring compound. Specific examples of the aromatic nitrogen-containing condensed ring compound include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercaptomethylbenzimidazole, 2-mercaptomethylbenzoxazole, and 2-mercapto. Methylbenzothiazole, dibenzoxazyldisulfide, dibenzothiazyldisulfide, 2- (phenylthio) benzothiazole, 2-mercaptobenzimidazole sodium salt, 2-mercaptobenzimidazole zinc (II)
A salt, a copper (II) salt of 2-mercaptobenzimidazole,
2-Mercaptobenzimidazole copper (II) salt, 2-
Nickel (II) salt of mercaptobenzimidazole, 2
-Zinc (II) salt of mercaptobenzothiazole, Copper (II) salt of 2-mercaptobenzothiazole, Zinc (II) salt of 2-mercaptomethylbenzimidazole, Zinc (II) salt of 2-mercaptomethylbenzothiazole, 2 -Mercapto dimethyl benzimidazole, 2-mercapto dimethyl benzoxazole, 2-mercapto dimethyl benzothiazole etc. can be illustrated. Among these sulfur compounds, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercaptomethylbenzothiazole, dibenzothiazyldisulfide, and zinc (II) of 2-mercaptobenzimidazole. Salt, 2-mercaptobenzothiazole zinc (II) salt, and zinc (II) salt of 2-mercaptomethylbenzothiazole are preferable, and particularly zinc (2-mercaptobenzothiazole, 2-mercaptomethylbenzothiazole, and zinc 2-mercaptobenzothiazole ( II) salts and zinc (II) salts of 2-mercaptomethylbenzothiazole are preferred.

In the photocurable composition of the present invention, the mixing ratio of the radical polymerizable monomer (A), the composite filler (B) and the photopolymerization initiator is 100 parts by weight of the radical polymerizable monomer. The composite filler (B) is usually 20 to 9
The amount is 00 parts by weight, preferably 50 to 800 parts by weight. In addition, the mixing ratio of the photopolymerization initiator (C) is such that the amount of α is 100 parts by weight of the radical-polymerizable monomer.
The ketocarbonyl compound (C ₁ ) is usually 0.01 to 15
The amount is preferably 0.05 to 10 parts by weight, and the blending ratio of the amines or the aromatic nitrogen-containing condensed ring compound (C ₂ ) is the radical polymerizable monomer (A).
It is usually 0.01 to 15 parts by weight, preferably 0.05 to 10 parts by weight, relative to 100 parts by weight.

The photocurable composition of the present invention may further contain other components, such as a powdered inorganic filler, an organic polymer, a tackifier, a photosensitizer, a polymerization regulator, a polymerization inhibitor and the like, if necessary. It can also be blended. Specific examples of the powdery inorganic filler include kaolin, talc, clay, calcium carbonate, silica, silica-alumina, alumina, titanium oxide, calcium phosphate, glass powder and quartz powder. The organic polymer is wax, ethylene.
Examples thereof include vinyl acetate copolymer, polymethyl acrylate, polymethyl methacrylate and copolymers thereof. The mixing ratio of these components is appropriate.

By irradiating the photocurable composition of the present invention with light, polymerization occurs and the composition is cured. The light beam may be a natural light beam or an artificial light beam, and a light beam from the ultraviolet region to the visible region can be adopted. As the artificial light ray, a high pressure mercury lamp, a medium pressure mercury lamp, a low pressure mercury lamp, a halogen lamp, a tungsten lamp or the like can be used. The temperature at the time of photocuring is usually 0 to 80 ° C, preferably 5 to 50 ° C, and the time of light irradiation is usually 1
Seconds to 5 minutes.

〔Example〕

 Next, the present invention will be specifically described with reference to examples.

The evaluation of the photocurable composition of the present invention is shown below, and a production example of the composite filler (B) is shown in Reference Examples. The following abbreviations used in the following Examples and Comparative Examples respectively represent the following compounds.

TEGMA …… triethylene glycol dimethacrylate, RDMA …… 1,3-dimethacryloxyethoxybenzene, UDMA …… 2,2,4-trimethylhexamethylenediamine, 1 mol of diisocyanate and 2 mol of 2-hydroxyethyl methacrylate Adduct of CQ …… camphorquinone, DEABA …… 4-diethylaminobenzoic acid, DMABA …… 4-dimethylaminobenzoic acid, DMABA …… 4-methyldimethyldimethylbenzoate, DMPT …… N, N-dimethyl- p-Toluidine, MBZTZ ... 2-Mercaptobenzothiazole, RM-50 ... Fine powder silica (average particle size 40mμ) manufactured by Nippon Aerosil Co., Ltd., FS-90 ... Fused silica manufactured by Toshiba Ballotini Co., Ltd. ( Average particle size 13 μ), [Evaluation method] Table 1 shows the test items and their evaluation methods.

[Manufacturing Method of Composite Filler] Reference Example 1 A solution prepared by dissolving 0.1 g of benzoyl peroxide in 10 g of trimethacrylate of trimethylolpropane was placed in a mortar and pestle, and further hydrophobic fine silica (Aerosil R972 manufactured by Nippon Aerosil Co., Ltd., Average particle size 16m
μ) was added little by little and mixed. When the viscosity gradually increased and became dull, the mixture was hung on a small rubber roll, and silica powder was intermittently added to give a final addition amount of fine silica powder of 9.5 g. Remove the obtained paste from the roll and press 1 at a mold temperature of 110 ℃.
It was heat-cured at a pressure of 50 kg / cm ² to 200 kg / cm ² for 10 minutes. The cured product was crushed with a ball mill to obtain 18.0 g of a composite filler that passed through a 230 mesh sieve. The average particle size of this composite filler was 11μ.

When the trimethacrylate cured product constituting the composite filler was analyzed by an infrared spectrophotometer, absorption at 1640 cm ^-1 was observed and it was found that the double bond remained.

Reference Example 2 In Reference Example 1, R-972 was used as the hydrophobic finely divided silica.
A composite filler was produced by the method described in Reference Example 1 except that OX-50 (manufactured by Nippon Aerosil Co., Ltd., Aerosil OX-50, average particle size 40 mμ) was used in place of The average particle size of this composite filler was 13μ.

Example 1 Triethylene glycol dimethacrylate 15 g, 1,3
15 g of dimethacryloxyethoxybenzene, reference example 1
70 g of the composite filler described above and 4 mg of hydroquinone monomethyl ether were kneaded at 35 ° C. with a two-roll mill to prepare a composition. A photocurable composition was prepared by thoroughly mixing 10 g of this composition with 45 mg of camphorquinone and 45 mg of 4-diethylaminobenzoic acid with a spatula. The test piece to be subjected to the test is filled with the paste in a mold, covered with cellophane paper, and then a visible light irradiator (Kulzer,
Translux) using visible light (wavelength 350-700nm)
Was irradiated for 30 seconds (when the test piece was larger than the irradiation port, the irradiation port was shifted and irradiation was repeated) to prepare a cured product. The results are shown in Table 2.

Example 2 18.7 g of triethylene glycol dimethacrylate, 18.7 g of 1,3-dimethacryloxyethoxybenzene in Example 1, 47.6 g of the composite filler described in Reference Example 1 and fine powder silica RM-50 (Nippon Aerosil Co., Ltd.) The photocurable composition and each test piece were prepared by the method described in Example 1 except that 15 g of finely powdered silica having an average particle size of 40 mμ) was used. The results are shown in Table 2.

Examples 3 to 9 and Comparative Example 1 In Example 2, except that the radical polymerizable monomer, the filler and the photopolymerization initiator described in Table 2 were used in the composition described in Table 2, The photocurable composition and each test piece were produced by the method described in 2. The results are shown in Table 2.

Claims (1)

[Claims] 1. A composite filler comprising (A) a radical-polymerizable monomer, (B) a fine-particle inorganic filler, the surface of which is polymerized with a radical-polymerizable polyfunctional (meth) acrylate-based monomer, and ( C) A photocurable composition comprising a photopolymerization initiator