JPH0322842B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a composite filling material, particularly a composite filling material suitable for use in a dental composite restorative material. More specifically, it has excellent surface smoothness and high surface hardness.
The present invention relates to a composite filler used in a composite restorative material with a small coefficient of thermal expansion. Conventional composite fillers are, for example, disclosed in Japanese Patent Application Laid-Open No.
The particle size is 20 mμ as described in No. 107189.
It is obtained by polymerizing and pulverizing a mixture of the following ultrafine particle silica and a known vinyl monomer. Since the particle diameter of this ultrafine silica particle is 20 mμ or less, the mixing ratio with the vinyl monomer must be as low as 30% by weight or less. As a result, when conventional composite fillers are used in composite restorative materials, they have the disadvantage of low surface hardness and large coefficient of thermal expansion. In order to solve the above drawbacks, the present inventors have conducted extensive research and have developed a composite filler made of a vinyl polymer containing an inorganic oxide with a particle size ranging from 0.1 μm to 1.0 μm and a spherical shape. It has been found and already proposed that by using the present invention in a composite restorative material, it is possible to obtain a composite restorative material that has excellent surface smoothness, high surface hardness, and a small coefficient of thermal expansion. The present invention proposes a composite filler whose surface is treated with an acid halide compound having an ethylenically unsaturated bond. The inorganic oxide used in the present invention has at least one metal oxide selected from the group consisting of Groups 1, 2, 3, and 3 of the periodic table, and silica as main components, Particle size is 0.1~1.0μm
and is spherical in shape. The particle size distribution of the inorganic oxide used in the present invention is not particularly limited, but a sharp one in which the standard deviation of the distribution is within 1.30 is best suited for the purpose of the present invention. Both the particle size and the particle shape are very important factors, and the object of the present invention cannot be achieved if any of the conditions are absent. For example, the particle size of inorganic oxide
If it is smaller than 0.1 μm, the viscosity will increase significantly when it is kneaded with a polymerizable vinyl monomer to form a paste mixture, and if you try to prevent the increase in viscosity by increasing the blending ratio, the operability will deteriorate. Therefore, it cannot be used as a material for practical use. Further, if the particle size is larger than 1.0 μm, it is not preferable because there are defects such as a decrease in the smoothness of the surface of the resin after polymerization and curing of the vinyl monomer, and further a decrease in surface hardness. In addition, if the standard deviation value of the particle size distribution becomes larger than 1.30, the operability of the composite composition may deteriorate, so generally, it is preferable to use a particle size distribution with a standard deviation value of 1.30 or less. is preferred. Furthermore, even if the inorganic oxide has a particle size in the range of 0.1 to 1.0 μm and the standard deviation value of the particle size distribution is within 1.30, if the shape of the particle is spherical, the present invention as described above is not possible. However, the effects, especially in terms of surface smoothness, surface hardness, etc., cannot be satisfactory. The method for producing the inorganic oxide is not particularly limited, and any method may be employed, but the following method is generally suitably employed. A mixed solution containing a hydrolyzable organosilicon compound and a hydrolyzable organic compound of at least one metal selected from the group consisting of metals of Groups 1, 2, 3 and 3 of the periodic table. The organosilicon compound and the organic compounds of metals of Groups 1, 2, 3 and 3 of the periodic table are dissolved in an alkaline solvent, but the reaction product is not substantially dissolved, and the reaction product is hydrolyzed by adding it to an alkaline solvent. An inorganic oxide whose main constituents are at least one metal oxide selected from the group consisting of metal oxides of Groups 1, 2, 3 and 3 of the periodic table obtained by precipitating silica. A method for manufacturing a product is preferably employed.
In general, it is preferable to reduce the number of silanol groups on the surface of industrially obtained inorganic oxides in order to maintain surface stability. For this purpose, a method of drying the spherical inorganic oxide and then firing it at a temperature of 500 to 1000°C is often suitably employed. During the firing, some of the inorganic oxides may sinter and aggregate, so
Usually, it is preferable to use a crusher, vibrating ball mill, jet pulverizer, etc. to loosen the aggregated particles.
Generally, in order to maintain stability, the fired inorganic oxide is most preferably used after surface treatment using an organic silicon compound. The surface treatment method described above is not particularly limited and may be performed by any known method, such as using an inorganic oxide and a known organosilicon compound such as γ-methacryloxypropyltrimethoxysilane or vinyltriethoxysilane in a mixed solvent of alcohol/water. A method is adopted in which the solvent is removed after contacting for a period of time. The particle size and shape of the inorganic oxide used in the present invention can be confirmed by taking a microscopic photograph, and the standard deviation value of the particle size distribution can be determined within the unit area of the microscopic photograph or unit field of view of the microscope. It can be calculated from the number of particles existing in and the diameter of each particle using the calculation formula described below. The above-mentioned microscopic photograph may be any photograph as long as the particle shape of the inorganic oxide can be observed, but in general, scanning electron micrographs, transmission electron micrographs, etc. are suitable. As mentioned above, spherical particles are used as the inorganic oxide used in the present invention, but whether or not the particles are spherical can be confirmed by measuring the specific surface area of the inorganic oxide in addition to the above-mentioned microscope. I can do it. For example, if the specific surface area of an inorganic oxide having a particle size in the range of 0.1 to 1.0 μm is about 4.0 to 40.0 m ² /g, it almost matches the specific surface area calculated assuming a perfect spherical shape. Therefore, the inorganic oxide used in the present invention preferably has a specific surface area of 4.0 to 40.0 m ² /g. The vinyl polymer used in the present invention is obtained by polymerizing a polymerizable vinyl monomer. The polymerizable vinyl monomer is not particularly limited,
Known monomers are used. Specific examples of these typical examples are as follows. (i) Monofunctional vinyl monomers Methyl methacrylate; Ethyl methacrylate; Isopropyl methacrylate; Hydroxyethyl methacrylate; Tetrahydrofurfuryl methacrylate; Glycidyl methacrylate; and these acrylates Difunctional vinyl monomers (i) Aromatic compounds 2,2- Bis(methacryloxyphenyl)
Propane; 2,2-bis[4-(3-methacryloxy)-2-hydroxypropoxyphenyl)propane; 2,2-bis(4-methacryloxyethoxyphenyl)propane; 2,
2-bis(4-methacryloxydiethoxyphenyl)propane; 2,2-bis(4-methacryloxytetraethoxyphenyl)propane; 2,2-bis(4-methacryloxypentaethoxyphenyl)propane; 2 , 2-bis(4-methacryloxydipropoxyphenyl)propane; 2(4-methacryloxyethoxyphenyl)-2(4-methacryloxydiethoxyphenyl)propane; 2(4-methacryloxydiethoxyphenyl) )-2(4-methacryloxytriethoxyphenyl)propane; 2(4-methacryloxydipropoxyphenyl)-2(4-methacryloxytriethoxyphenyl)propane; 2,2-bis(4-methacryloxypropoxyphenyl) 2,2-bis(4-methacryloxyisopropoxyphenyl)propane and their acrylates (ii) Aliphatic compounds Ethylene glycol dimethacrylate; diethylene glycol dimethacrylate; triethylene glycol dimethacrylate; butylene glycol Dimethacrylate; Neopentyl glycol dimethacrylate; Propylene glycol dimethacrylate; 1,3-butanediol dimethacrylate; 1,4-butanediol dimethacrylate; 1,6-hexanediol dimethacrylate and these acrylates Trifunctional vinyl monomers Trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol trimethacrylate, trimethylolmethane trimethacrylate and these acrylates Tetrafunctional vinyl monomers Pentaerythritol tetramethacrylate, pentaerythritol tetraacrylate and urethanes having the structural formula shown below monomer of the system The proportion of inorganic oxide in the composite filler made of vinyl polymer containing inorganic oxide of the present invention varies depending on the type of inorganic oxide, the type of vinyl monomer, etc., and cannot be determined unconditionally. It may be determined and used as appropriate. In general, inorganic oxides
It is preferable to select the amount within the range of 50 to 9% by weight. When a composite filler using the above-mentioned inorganic oxide, especially a composite filler whose ratio is within the above range, is used as a composite repair material, it has good surface smoothness, surface hardness, and coefficient of thermal expansion. You can get something. In the present invention, the method for producing the vinyl polymer containing the above-mentioned inorganic oxide is not particularly limited.
For example, a method of mixing and polymerizing a polymerizable vinyl monomer and an inorganic oxide that are polymerized to form a vinyl polymer as described above, and a vinyl polymer that is polymerized by the method described above and then polymerized with a separate polymerizable vinyl monomer. or, after polymerization by the method described above, mixing an inorganic oxide therewith. Among the above methods, the method of mixing and polymerizing a polymerizable vinyl monomer and an inorganic oxide will be described below. In order to polymerize the polymerizable vinyl monomer, it is preferable to use a polymerization initiator. The polymerization initiator is not particularly limited, and any known radical generator can be used without any restrictions. For example, benzoyl peroxide, parachlorobenzoyl peroxide, 2,
4-dichlorobenzoyl peroxide, acetyl peroxide, lauroyl peroxide,
Organic peroxides such as tertiary butyl hydroperoxide, cumene hydroperoxide, 2,5-dimethylhexane 2,5-dihydroperoxide, methyl ethyl ketone peroxide, tertiary butyl peroxybenzoate,
Azo compounds such as azobisisobutyronitrile, organometallic compounds such as tributylboric acid, and the like are suitable. Furthermore, a photosensitizer can be used as a polymerization initiator. Examples of the photosensitizer include benzoin, benzoin methyl ether, benzoin ethyl ethyl, acetoin benzophenone, P-chlorobenzophenone, P-
Examples include methoxybenzophenone. The amount of the polymerization initiator added may be selected from the range of 0.1 to 3% by weight based on the polymerizable vinyl monomer. Generally, polymerization can also be carried out under an inert gas atmosphere such as nitrogen or argon to prevent discoloration of the polymer. Although polymerization under atmospheric pressure is generally sufficient, it can also be carried out under increased pressure if necessary. Further, the polymerization temperature is appropriately selected depending on the decomposition temperature of the polymerization initiator, and can usually be appropriately selected from the range of 20 to 200°C. Next, the particle size and average particle size of the composite filler of the present invention are selected within a practically appropriate range. Normal particle size is 0.1μm
range from 150μm, average particle size from 1μm to 40μm
It is preferable that it is in the range of . The composite filler having the above particle size range can be obtained by polymerization using the method described above, but once it has been polymerized as a block-shaped vinyl polymer containing an inorganic oxide,
It can also be obtained by grinding the polymer. The method of pulverizing is not particularly limited, but in general, a method using a machine such as a ball mill, a crusher, a vibrating ball mill, a jet pulverizer, or a device such as a mortar is suitable. Also, when crushing the above,
It can also be carried out in an inert gas atmosphere or in a solvent such as alcohol or benzene to prevent the pulverized material from being oxidized and colored. Also, antioxidants such as 2,5-ditertiary-butyl-4
- Pulverization can also be carried out using known phenol compounds such as methylphenol and hydroquinone monomethyl ether. The composite filler of the present invention is further surface-treated with an acid halide compound having ethylenically unsaturated bonds. By using a composite filler surface-treated with the above acid halide compound, the compressive strength and bending strength of the cured composite restorative material are improved. Examples of the ethylenically unsaturated bond include a vinyl group, an allyl group, an acryloyl group, and a methacryloyl group. As the acid halide compound having such an ethylenically unsaturated bond, known compounds can be used without particular limitation. Among the above-mentioned acid halide polymers, those having an ethylenically unsaturated bond at one end of the molecule and an acid halide group at the other end are preferable in order to better exhibit the effect of surface treatment. Examples of such acid halide compounds include those represented by the following structural formula. However, R ₁ = -H or -CH ₃ , R ₂ is -
CH ₂ CH ₂ O−,

[Formula] −CH ₂ CH ₂ CH ₂ O− or −CH ₂ CH ₂ CH ₂ CH ₂ O−,
n is an integer from 1 to 10, R ₃ is -CH=CH- or -
Represents CH ₂ CH ₂ −. X is -F, -Cl, -Br or -I. Among the acid halide compounds represented by the above structural formula, acid chloride compounds are most preferably used because of their ease of reaction with the composite filler surface and ease of handling. As a method for surface treatment of composite fillers with the above acid halide compound having ethylenically unsaturated bonds,
A known method is employed. For example, the composite filler is brought into contact with an acid halide compound having an ethylenically unsaturated bond in an inert solvent that does not react with the acid halide compound, such as benzene, toluene, cyclohexane, methylene chloride, chloroform, tetrahydrofuran, dioxane, or ethyl ether. There are several methods. The temperature at which the two are brought into contact may be selected within the range from room temperature to the boiling point of the solvent used. The amount of acid halide compound used is
It is preferable to select from the range of 0.1 to 10 parts by weight per 100 parts by weight. When the above acid halide compound and composite filler are brought into contact, the acid halide compound reacts with the composite filler and generates hydrogen halides such as hydrogen chloride and hydrogen fluoride, so triethylamine is used as a trapping agent. It is preferable to add such tertiary amines. When a composite filler surface-treated with an acid halide compound having an ethylenically unsaturated bond is used as a component of a composite restorative material, the various performances of the composite restorative material are improved for the following reasons. The hydroxyl groups present on the surface of the composite filling material react with the acid halide groups of the acid halide compound, and on the other hand, the polymerizable vinyl monomer, which is a component of the composite restorative material, and the ethylenically unsaturated bonds of the acid halide compound undergo a polymerization reaction. do. Therefore, it is considered that the acid halide compound plays a role in bonding the composite filler in the composite restorative material and the vinyl polymer obtained by polymerizing the polymerizable vinyl monomer. By using the surface-treated composite filler of the present invention as described above, various performances of the composite restorative material are improved. That is, the surface smoothness (represented by surface roughness) of the composite restorative material is extremely smooth, the surface hardness is high, and the coefficient of thermal expansion is small. Moreover, a composite repair material with high compressive strength and high bending strength can be obtained. Therefore, a composite restorative material using the surface-treated composite filler of the present invention is an extremely suitable material, for example, as a dental composite restorative material. Moreover, the operability for applying the composite restorative material to a dental material is improved. The method for evaluating the operability will be described in detail later, but it can be expressed by the maximum stringy length of the paste-like composite restorative material. The shorter the maximum string length, the better the operability, and the longer the maximum length, the worse the operability. Usually, the maximum string length is preferably in the range of 0 to 20 cm. As described above, the surface-treated composite filling material of the present invention can provide an extremely ideal composite restorative material, and its usefulness is extremely large. EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples. The physical properties of the inorganic oxides (particle size, standard deviation of particle size distribution, specific surface area) shown in the examples below were measured, and the physical properties of the cured composite restorative material (compressive strength, surface roughness, surface hardness) were measured. , coefficient of thermal expansion) and the maximum stringy length of the paste were measured according to the following method. (1) Standard deviation value of particle size and particle size distribution Take a scanning electron micrograph of a powder, and calculate the number of particles observed within a unit field of view of the photograph (n),
and the particle diameter (diameter X _i ), which is calculated using the following formula. Standard deviation value = +σ _o-1 /X However (2) Specific surface area Shibata Chemical Equipment Co., Ltd. Rapid surface measuring device SA−
1000 was used. The measurement principle is the BET method. (3) Paste preparation and curing method for composite restorative material First, the composite filler and vinyl monomer were placed in a predetermined ratio in an agate mortar and sufficiently kneaded until a uniform paste was obtained. Next, the paste was divided into two equal parts, and a polymerization accelerator was further added to one paste and thoroughly mixed (this was referred to as paste A).
Further, an organic peroxide catalyst was added to the other paste and thoroughly mixed (this is referred to as paste B).
Next, equal amounts of paste A and paste B were kneaded for about 30 seconds, filled into a mold, and hardened. (4) Compressive strength Paste A and paste B were mixed, polymerized for 30 minutes at room temperature, and then immersed in water at 37°C for 24 hours to prepare test pieces. Its size and shape are cylindrical with a diameter of 6 mm and a height of 12 mm. This test piece was tested on a test machine (Toyo Baudouin UTM-
5T), crosshead speed 10mm/
Compressive strength was measured at min. (5) Surface roughness Mix paste A and paste B and
After polymerizing for 30 minutes, the sample was immersed in water at 37°C for 24 hours. Its size and shape are 1.5
It is a plate-shaped piece measuring 10 x 10 mm. Loading the specimen
After being abraded for 1500 m with a toothbrush of 400 g, the 10-point average roughness was determined using a surface roughness meter (Surfcom A-100). (6) Surface hardness Mix paste A and paste B and heat at room temperature.
After polymerizing for 30 minutes, the test piece was immersed in water at 37°C for 24 hours. Its size and shape are
It is disc-shaped, measuring 2.5 x 10 mm. The measurement used a micropurinelle hardness test. (7) Coefficient of thermal expansion Mix paste A and paste B and mix at room temperature.
After polymerizing for 30 minutes, the test piece was left at 37°C for 24 hours. Its size is 4mmφ×12mm
It is cylindrical. The measurement was performed using a thermal expansion measurement device (TM-12) manufactured by Rigaku Denki, and the measurement temperature range was 20°C to 50°C. (8) Maximum length of stringing Place approximately 10 g of paste in a cylindrical glass container with a depth of 10 mm and a diameter of 30 mm, and smooth the surface of the paste. Insert a glass rod with a diameter of 5 mm and a length of 100 mm into the smooth surface of the paste at a 45° angle to a depth of 5 mm. Fix the container and pull the glass rod vertically at a constant speed (10 cm/sec) to cause the paste to become stringy. The length of the string until it breaks is the maximum length of the string. (9) Bending strength Mix paste A and paste B and
After polymerizing for 30 minutes, the test piece was immersed in water at 37°C for 24 hours. Its size and shape are 2
It has a prismatic shape with dimensions of 2 x 25 mm. The bending test was conducted using a bending test device with a distance between fulcrums of 20 mm attached to Toyo Baudouin's UTM-5T, and a cross speed of 0.5 mm/min. The abbreviations used in the examples are as follows unless otherwise specified. Bis-GMA; 2,2-bis(4-(2-hydroxy-3-methacryloxyphenyl)propane) Bis-MPP; di(4-methacryloxyethoxyphenyl)propane TEGDMA; triethylene glycol dimethacrylate DEGDMA; diethylene glycol Dimethacrylate TMPT; Trimethylolpropane triacrylate TMM-3M; Pentaerythritol trimethacrylate TMM-4M; Pentaerythritol tetramethacrylate MMA; Methyl methacrylate NPG; Neopentyl glycol dimethacrylate IPA; Isopropyl alcohol MeCH; Methyl alcohol EtOH; Ethyl alcohol MAE: Maleic acid chloride mono[acryloyloxyethyl] ester MMAE: Maleic acid chloride mono[methacryloyloxyethyl] ester MAD: Maleic acid chloride mono[acryloyloxydiethylene glycol] ester MAT: Maleic acid chloride mono[acryloyloxytriethylene glycol] ester SAE; Succinic acid chloride mono[acryloyloxyethyl] ester SAP; Succinic acid chloride mono[acryloyloxypropylene glycol] ester TAE; Trimellitic acid chloride mono[acryloyloxyethyl] ester PAE; Pyromellitic acid chloride mono[acryloyloxyethyl] ester PHAE ; Phthalic acid chloride mono[acryloyloxyethyl] ester MMAD; Maleic acid chloride mono[methacryloyloxydiethylene glycol] ester MMAT; Maleic acid chloride mono[methacryloyloxytriethylene glycol]
Ester SMAE; Succinic acid chloride mono[methacryloyloxyethyl] ester TMAE; Trimellitic acid chloride mono[methacryloyloxyethyl] ester PMAE; Pyromellitic acid chloride mono[methacryloyloxyethyl] ester Example 1 Production method of inorganic oxide 0.1% hydrochloric acid 4.0 g and tetraethyl silicate 158
g (Si(OC ₂ H ₅ ) ₄ , manufactured by Nihon Colcoat Chemical Co., Ltd., product name: ethyl silicate 28) and methanol 1.2
The solution was hydrolyzed with stirring at room temperature for about 2 hours. Thereafter, this was converted into tetrabutyl titanate (Ti(O-nC ₄ H ₉ ) ₄ , manufactured by Nippon Soda) 40.9
g was added to a solution dissolved in 0.5 isopropanol with stirring to prepare a mixed solution of tetraethyl silicate hydrolyzate and tetrabutyl titanate. Next, introduce 2.5 methanol into a glass reaction vessel with an internal volume of 10 and a stirrer, add 500 g of ammonia aqueous solution (concentration 25 Wt%) to prepare an ammonia alcohol solution, and make silica seeds in this. A solution of 4.0 g of tetraethyl silicate dissolved in 100 ml of methanol was added over about 5 minutes as an organosilicon compound solution for
Five minutes after the completion of the addition, when the reaction solution was slightly milky white, the above mixed solution was added over a period of about 2 hours while maintaining the temperature of the reaction vessel at 20° C. to precipitate the reaction product. Thereafter, a solution of 128 g of tetraethyl silicate dissolved in 0.5 methanol was added over about 2 hours to the system in which the reaction product had precipitated. After the addition was completed, stirring was continued for an additional hour, and then the solvent was removed from the milky white reaction liquid using an evaporator, and the mixture was further dried at 80°C under reduced pressure to obtain a milky white powder. Further, this milky white powder was fired at 900°C for 4 hours and then dispersed in an agate mortar to obtain an inorganic oxide whose main components were silica and titania. Observation using a scanning electron microscope reveals that the particle size of this inorganic oxide is in the range of 0.10 to 0.20 μm, with an average particle size of
The particle size was 0.13 μm, and the shape was a perfect sphere. Furthermore, the standard deviation value of the particle size distribution was 1.08, and the specific surface area was 20 m ² /g. The obtained inorganic oxide was further surface-treated with γ-methacryloxypropyltrimethoxysilane. Surface treatment involves adding 8% by weight of γ-methacryloxypropyltrimethoxysilane to the inorganic oxide, refluxing in a water-ethanol solvent at 80°C for 2 hours, removing the solvent with an evaporator, and drying in vacuum. I went to bed. Next, a method for producing a composite filler using the above inorganic oxide will be described. Manufacturing method of composite filler Bis-GMA is added to the above surface-treated inorganic oxide.
A mixture of vinyl monomers with TEGDMA (mixing ratio: Bis-GMA 60% by weight, TEGDMA 40% by weight),
A paste was obtained by thoroughly kneading azobisisobutyronitrile (0.5 parts by weight per 100 parts by weight of the vinyl monomer mixture) and ethanol (15 parts by weight per 100 parts by weight of the vinyl monomer mixture). The paste was placed under vacuum to remove air bubbles and ethanol. The loading amount of inorganic oxide in the paste after removing air bubbles and ethanol was 78.0% by weight. Thereafter, this paste was polymerized under a nitrogen pressure of 5 kg/cm ² at a polymerization temperature of 120°C and a polymerization time of 1 hour.
A polymer was obtained. This polymer was crushed in a mortar to a size of 5 mm or less in diameter, and then further crushed in a grinder for 1 hour. After crushing, a composite filler that passed through a 250 mesh sieve was obtained. The composite filler had a specific gravity of 2.21 and a surface hardness of 72. Next, 2.5 parts by weight of methacrylic acid chloride, 5.0 parts by weight of triethylamine, and 250 parts by weight of toluene were mixed with 100 parts by weight of the composite filler in a tightly closed Erlenmeyer flask, and the mixture was stirred for 12 hours. next,
The mixed solution in the Erlenmeyer flask was filtered, further washed with methanol, and dried under reduced pressure at room temperature to obtain a surface-treated composite filler. Next, 10 g of a filler mixture of the above-mentioned surface-treated composite filler and the above-mentioned surface-treated inorganic oxide (mixing ratio: 50% by weight of composite filler, 50% by weight of inorganic oxide), Bis-GMA and TEGDMA were added. vinyl monomer mixture (mixing ratio: Bis-GMA 60% by weight,
TEGDMA (40% by weight), 3.2 g of benzoyl peroxide (2.0 parts by weight based on 100 parts by weight of the vinyl monomer mixture), and 2,5-ditertiary
Butyl-4-methylphenol (0.1 parts by weight per 100 parts by weight of the vinyl monomer mixture) was mixed to obtain a paste. (This paste is referred to as paste B) 10 g of the same filler mixture as above, 3.2 g of the above vinyl monomer mixture, N,N-bis-(2-hydroxyethyl)-4-methylaniline (1.2 g of the above vinyl monomer mixture) weight%) and 2,5-
A paste was obtained by mixing ditertiary-butyl-4-methylphenol (0.02% by weight in the above vinyl monomer mixture). (This paste is called paste A.) Take equal amounts of paste B and paste A,
As a result of measuring the physical properties of the composite restorative material that was kneaded and cured at room temperature for 30 seconds, the compressive strength was 3840 Kg/cm ² and the surface roughness was
Paste B had a surface hardness of 62, a bending strength of 1230 Kg/cm ² , a coefficient of thermal expansion of 31×10 ⁻⁶ /° C., and a maximum stringing length of 5 cm. Example 2 Method for producing inorganic oxide Tetraethyl silicate (Si(OC ₂ H ₅ ) ₄ ) distilled with 1.8 g of 0.5% hydrochloric acid, manufactured by Nippon Colcourt Chemical Co., Ltd.
Product name Ethyl silicate 28) 104g in methanol
0.2 and the solution was hydrolyzed at room temperature with stirring for about 1 hour. After that, tetrabutyl titanate (Ti(O-nC ₄ H ₉ ) ₄ , manufactured by Nippon Soda) was added to this.
A mixed solution (A) of tetraethyl silicate hydrolyzate and tetrabutyl titanate was prepared by adding 17.0 g to a solution dissolved in isopropanol 1.0 with stirring. Next, 7.8 g of barium bisisopentoxide and 104 g of tetraethyl silicate.
and aluminum trisec-butoxide (0.2 g) were dissolved in methanol (1.0 g), and the solution was refluxed at 90° C. for 30 minutes under a nitrogen atmosphere. Thereafter, the temperature was returned to room temperature, and this was used as a mixed solution (B). Further mixed solution (A)
and mixed solution (B) are mixed at room temperature, and this is mixed with the mixed solution (B).
It was set as (C). Next, fill a glass reaction vessel with an internal volume of 10 with a stirrer with 2.5 methanol, add 500 g of ammonia aqueous solution (concentration 25 wt%) to prepare an ammonia alcohol solution, and add the previously prepared mixture to this solution. Solution (C) was added over about 4 hours while maintaining the temperature of the reaction vessel at 20°C. A few minutes after the addition started, the reaction solution became milky white. 1 more after addition
After continuing to stir for an hour, the solvent was removed from the milky white reaction liquid using an evaporator, and the mixture was further dried under reduced pressure at 80°C to obtain a milky white powder. Further, this milky white powder was calcined at 900° C. for 4 hours, and then the agglomerates were loosened using a crusher to obtain an inorganic oxide whose main components were silica, titania, and barium oxide. As a result of observation using scanning electron microscopy, the shape of this inorganic oxide is spherical, and its particle size is 0.12~
It is in the range of 0.26μm, and the standard deviation value of the particle size is
It was 1.06. Also, the specific surface area by BET method is 30
m ² /g. According to X-ray analysis, approximately 2θ=
A gentle mountain-shaped absorption was observed around 25', confirming that it had an amorphous structure. Further, this milky white powder was calcined at 900° C. for 4 hours, and then the agglomerates were loosened using a crusher to obtain an inorganic oxide whose main components were silica, titania, and barium oxide. This inorganic oxide is further γ-
The surface was treated with methacryloxypropyltrimethoxysilane in the same manner as in Example 1. Method for manufacturing composite filler The above surface-treated inorganic oxide is coated with TMM-
A mixture of vinyl monomers of 3M and TMM-4M (mixing ratio is 30% by weight of TMM-3M, TMM-
4M70% by weight), lauroyl peroxide (0.2 parts by weight per 100 parts by weight of vinyl monomer mixture)
and ethanol (10 parts by weight per 100 parts by weight of the vinyl monomer mixture) were blended and sufficiently kneaded to obtain a paste. The paste was placed under vacuum to remove air bubbles and ethanol. After removing air bubbles and ethanol, the inorganic oxide loading in the paste was 76% by weight. Then add this paste 3
Polymerization was carried out at 90°C for 11 hours under argon pressure of Kg/ ^cm2 ,
A polymer was obtained. This polymer was ground in a ball mill for 5 hours and then further ground in a grinder for 1 hour. After crushing
A composite filler passing through a 400 mesh sieve was obtained.
The composite filler had a specific gravity of 2.40 and a surface hardness of 65. Next, 1.2 parts by weight of methacrylic acid fluoride, 2.5 parts by weight of triethylamine, and 250 parts by weight of benzene were mixed with 100 parts by weight of the above composite filler in an Erlenmeyer flask equipped with a reflux device purged with dry nitrogen, and stirred for 2 hours. did. Next, the mixed solution in the Erlenmeyer flask was filtered, further washed with methanol, and dried under reduced pressure at 50°C to obtain a surface-treated composite filler. Next, 10 g of a filler mixture of the above-mentioned surface-treated composite filler and the above-mentioned surface-treated inorganic oxide (the mixing ratio is 60% by weight of the composite filler and 40% by weight of the inorganic oxide), Bis-GMA and TEGDMA were added. Vinyl monomer mixture with TMPT (mixing ratio is Bis-
GMA42% by weight, TEGDMA21% by weight, TAPT30
3.5 g of benzoyl peroxide (2.0 parts by weight per 100 parts of the vinyl monomer mixture) and 2,5-ditertiary-butyl-4-
A paste was obtained by mixing methylphenol (0.1 parts by weight per 100 parts by weight of the vinyl monomer mixture). (This paste is referred to as paste B.) 10 g of the same filler mixture as above, Bis-GMA
and a vinyl monomer mixture of TEGDMA and TMPT (mixing ratio: Bis-GMA 42% by weight,
TEGDMA21wt%, TAPT30wt%) 3.2g,
N,N-bis-(2-hydroxyethyl)-4-methylaniline (1.2% by weight based on 100 parts by weight of the above vinyl monomer mixture) and hydroquinone momethyl ether (based on 100 parts by weight of the above vinyl monomer mixture)
0.02 parts by weight per 100 parts by weight) to obtain a paste. (This paste is referred to as Paste A.) As a result of measuring the physical properties of a cured composite restorative material obtained by mixing equal amounts of Paste A and Paste B in the same manner as in Example 1, the compressive strength was 3990.
Kg/ ^cm2 , surface roughness 0.6μm, surface hardness 63, bending strength
It had a weight of 1310Kg/cm ² and a coefficient of thermal expansion of 30×10 ^-6 /°C.
The maximum stringing length of Paste B was 5 cm. Example 3 Production method of inorganic oxide 52 g of tetraethyl silicate similar to that used in Example 1 and 15.6 g of zirconium tetrabutoxide (Zr(OC ₄ H ₉ ) ₄ ) were dissolved in 0.2 g of isopropyl alcohol, and this solution was dissolved in 0.2 g of isopropyl alcohol. ℃ and refluxed for 30 minutes under nitrogen atmosphere. Thereafter, the temperature was returned to room temperature, and this was used as a mixed solution (A). Next, 52 g of tetraethyl silicate and 6.1 g of strontium bismethoxide were added to 0.2 g of methanol, and this solution was refluxed at 80° C. for 30 minutes under a nitrogen atmosphere. Thereafter, the temperature was returned to room temperature, and this was used as a mixed solution (B). The mixed solution (A) and the mixed solution (B) were mixed at room temperature to form a mixed solution (C). Next, a glass reaction vessel with an internal volume of 10 and equipped with a stirrer was filled with 2.4 methanol, and 500 g of ammonia water (concentration 25% by weight) was added to prepare an ammoniacal alcohol solution. While keeping the reaction container at 20℃, mix the mixed solution (C).
The reaction product was added over about 4 hours to precipitate the reaction product. Subsequently, a solution consisting of 0.5 g of methanol containing 50 g of tetraethyl silicate was added to the system in which the reaction product had precipitated over a period of about 2 hours. After the addition was completed, stirring was continued for an additional hour, and then the solvent was removed from the milky white reaction liquid using an evaporator, followed by drying under reduced pressure to obtain a milky white powder. Further, this milky white powder was calcined at 900°C for 3 hours and then loosened using a crusher to obtain an inorganic oxide whose main components were silica, zirconia, and strontium oxide. From observation using a scanning electron microscope, this inorganic oxide has a particle size in the range of 0.10 to 0.25 μm, an average particle size of 0.17 μm, and a spherical shape.
Further, the standard deviation value of the particle size distribution was 1.25, and the specific surface area was 26 m ² /g. This inorganic oxide was further surface-treated with γ-methacryloxypropyltrimethoxysilane in the same manner as in Example 1. Manufacturing method of composite filler Bis−
Vinyl monomer mixture of GMA and TEGDMA (mixing ratio: Bis-GMA 70% by weight, TEGDMA 30% by weight), methyl ethyl ketone peroxide (1.0 parts by weight per 100 parts by weight of vinyl monomer mixture)
and methanol (20 parts by weight per 100 parts by weight of the vinyl monomer mixture) were mixed and sufficiently kneaded to obtain a paste. The paste was placed under vacuum to remove air bubbles and methanol. After removing air bubbles and methanol, the inorganic oxide loading in the paste was 80% by weight. Then add this paste 2
Polymerization was carried out at 120° C. for 4 hours under nitrogen pressure of Kg/cm ² to obtain a polymer. This polymer was ground in a ball mill for 6 hours and then further ground in a grinder for 1 hour. After crushing
A composite filler passing through a 200 mesh sieve was obtained.
The composite filler had a specific gravity of 2.51 and a surface hardness of 75. Next, 5 parts by weight of acrylic acid chloride and triethylamine were added to 100 parts by weight of the above composite filler.
5.0 parts by weight and 200 parts by weight of methylene chloride were mixed in a tightly closed Erlenmeyer flask and stirred for 12 hours. next,
The mixed solution in the Erlenmeyer flask was filtered, further washed with methanol, and dried under reduced pressure at room temperature to obtain a surface-treated composite filler. Next, paste A and paste B were prepared in the same manner as in Example 2 except that the above-mentioned surface-treated composite filler and the above-mentioned surface-treated inorganic oxide were used. As a result of measuring the physical properties of a cured composite restorative material obtained by mixing equal amounts of paste A and paste B in the same manner as in Example 1, the compressive strength
4.120 Kg/cm ² , surface hardness 60, surface roughness 0.6 μm, bending strength 1210 Kg/cm ² , and thermal expansion coefficient 32×10 ⁻⁶ /°C. The maximum stringing length of Paste B was 6 cm. Example 4 Production method of inorganic oxide 4.0 g of 0.1% hydrochloric acid water and 158 g of tetraethyl silicate similar to that used in Example 1 were mixed with 1.2 g of methanol.
The solution was hydrolyzed with stirring at room temperature for about 1 hour. Thereafter, this was added to a solution of 40.9 g of tetrabutyl titanate dissolved in 0.5 g of isopropanol with stirring to prepare a mixed solution (A) of a hydrolyzate of tetraethyl silicate and tetrabutyl titanate. On the other hand, a solution prepared by dissolving 0.2 g of sodium methylate in 0.5 g of methanol was mixed with the mixed solution (A) to form a mixed solution (B). Next, 2.5 liters of isopropanol was introduced into a glass reaction vessel with an internal volume of 10, equipped with a stirrer;
An ammoniacal alcohol solution was prepared by adding 500 g of ammonia aqueous solution (concentration 25% by weight). Add 5.0g of tetraethyl silicate to this in methanol.
Add the solution dissolved in 100ml over about 10 minutes,
Immediately after the addition was completed, the mixed solution (B) prepared earlier was added over about 6 hours while maintaining the temperature of the reaction vessel at 20°C to precipitate the reaction product. Thereafter, a solution of 128 g of tetraethyl silicate and 0.1 g of sodium methylate dissolved in 0.5 methanol was added over about 3 hours to the system in which the reaction product had precipitated. After the addition was completed, stirring was continued for an additional hour, and the solvent was removed from the milky white reaction liquid using an evaporator, followed by further drying at 100°C under reduced pressure to obtain a milky white powder. Further, this milky white powder was calcined at 1000° C. for 1 hour and then loosened using a crusher to obtain an inorganic oxide whose main components were silica, titania and sodium oxide. From observation using a scanning electron microscope, the particle size of this inorganic oxide is in the range of 0.20 to 0.40 μm.
The average particle size is 0.28 μm, the shape is spherical, the standard deviation value of the particle size distribution is 1.25, and the specific surface area is
It was 15m ² /g. The obtained inorganic oxide was further surface-treated using γ-methacryloxysilane in the same manner as in Example 1. Manufacturing method of composite filler Bis−
Vinyl monomer mixture of GMA, TEGDMA and TMPT (mixing ratio Bis-GMA 42% by weight,
TEGDMA (18% by weight, TMPT (30% by weight)) and benzoyl peroxide (0.1 parts by weight per 100 parts by weight of the vinyl monomer mixture) were blended and sufficiently kneaded to obtain a paste. The paste was placed under vacuum to remove air bubbles. The filling amount of inorganic oxide in the paste from which air bubbles were removed was 65% by weight. Thereafter, this paste was polymerized at 90° C. for 4 hours under a nitrogen pressure of 5 kg/cm ² to obtain a polymer. This polymer was pulverized for 1 hour using a vibrating ball mill, and then further pulverized for 1 hour using a crusher in an ethanol solvent. Thereafter, it was washed with ethanol and filtered to obtain a composite filler that passed through a 250-mesh sieve. Add this to 80 more
It was vacuum dried at ℃ for 8 hours. The dried composite filler had a specific gravity of 2.10 and a surface hardness of 70. Next, 1.0 parts by weight of methacrylic acid bromide, 2.0 parts by weight of triethylamine, and 300 parts by weight of dioxane were mixed with 100 parts by weight of the composite filler in a tightly closed Erlenmeyer flask and stirred for 8 hours. Next, the mixed solution in the Erlenmeyer flask was filtered, further washed with methanol, and dried under reduced pressure at room temperature to obtain a surface-treated composite filler. Next, paste A and paste B were prepared in the same manner as in Example 1 except that the above-mentioned surface-treated composite filler and the above-mentioned surface-treated inorganic oxide were used. As a result of measuring the physical properties of a cured composite restorative material obtained by mixing equal amounts of paste A and paste B in the same manner as in Example 1, the compressive strength was 3840.
Kg/cm ² , surface roughness 0.6μm, surface hardness 61, bending strength
It had a weight of 1300Kg/cm ² and a coefficient of thermal expansion of 31×10 ^-6 /°C.
The maximum stringing length of Paste B was 2 cm. Example 5 A surface-treated inorganic oxide was obtained in the same manner as in Example 1 except that the raw material composition of the mixed solution shown in Table 1 was used. Next, a composite filler was obtained which was surface-treated in the same manner as in Example 1 except that this inorganic oxide and the vinyl monomer mixture shown in Table 1 were used. Next, paste A and paste B were prepared in the same manner as in Example 1 except that the above-mentioned surface-treated composite filler and the above-mentioned surface-treated inorganic oxide were used. Table 1 shows the results of measuring the physical properties of a cured composite restorative material obtained by mixing equal amounts of paste A and paste B in the same manner as in Example 1.

【table】

[Table] Example 6 A surface-treated inorganic oxide was obtained in the same manner as in Example 1 except that the raw material composition of the mixed solution shown in Table 2 was used. Next, a composite filler was obtained which was surface-treated in the same manner as in Example 2 except that this inorganic oxide, the vinyl monomer mixture shown in Table 2, and the acid halide compound were used. Next, paste A and paste B were prepared in the same manner as in Example 2 except that the above-mentioned surface-treated composite filler and the above-mentioned surface-treated inorganic oxide were used, and both pastes were mixed in equal amounts. The physical properties of the cured composite restorative material were measured. The results are shown in Table 2.

【table】

[Table] Example 7 A surface-treated inorganic oxide was obtained in the same manner as in Example 3 except that the composition in the mixed solution shown in Table 3 was used. Next, a composite filler was obtained which was surface-treated in the same manner as in Example 3 except that this inorganic oxide, the vinyl monomer mixture shown in Table 3, and the acid halide compound were used. Next, paste A and paste B were prepared in the same manner as in Example 3 except that the above-mentioned surface-treated composite filler and the above-mentioned surface-treated inorganic oxide were used, and both pastes were mixed in equal amounts. The physical properties of the cured composite restorative material obtained by mixing were measured. The results are shown in Table 3.

【table】

【table】

【table】

【table】

Claims (1)

[Claims] 1 The main constituents are silica and at least one metal oxide selected from the group consisting of Groups of the Periodic Table, Groups of the Periodic Table, Groups of the Periodic Table, and Groups of the Periodic Tables that can bond with silica, and have a particle size of 0.1 A composite filler made of a vinyl polymer containing an inorganic oxide with a size of ~1.0 μm and a spherical shape, the surface of which is treated with an acid halide compound having an ethylenically unsaturated bond.