JPH0425247B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a dental composition containing an organic composite filler. For dental materials whose main constituent is organic resin, various physical properties such as hardness, compressive strength, abrasion resistance, and water absorption are important, and inorganic fillers are blended into the resin to improve these properties. , so-called composite resins are being developed. However, in this case, since the inorganic filler and the organic resin have significantly different properties, they often lack interfacial compatibility such as compatibility and adhesion, and cannot exhibit sufficient improvement effects. In order to improve this point, for example, dental materials have been proposed in which a filler treated with a silane coupling agent is added to the glass surface, but a sufficient improvement has not yet been achieved. The present invention solves the above problems, and includes:
The present invention is based on the following general formula (In the formula, R ₁ is H, an alkyl group having 1 to 20 carbon atoms,
X is -CONH,

[Formula] -COO (CH ₂ ) _n or -(CH ₂ ) _o , R ₂ and R ₃ are each H or an alkyl group having 1 to 15 carbon atoms, and R ₄ is an alkylene group having 1 to 15 carbon atoms. , m is an integer of 1 to 20, n is an integer of 0 to 20, Y is H, NH ₄ or an alkali metal atom) and at least one radically polymerizable sulfonic acid monomer or sulfonate monomer. The object of the present invention is to provide a dental composition comprising a vinyl compound and an organic composite filler obtained by polymerizing a vinyl monomer in a polymerization system in which an inorganic compound is dispersed. The composition of the present invention is characterized by an inorganic compound obtained by polymerizing a sulfonic acid monomer or a sulfonate monomer represented by the general formula [] and a vinyl monomer in the presence of an inorganic compound, and an organic polymer. By using a strongly integrated organic composite filler together with a vinyl compound, it is possible to significantly improve the hardness, mechanical strength, appearance, and other properties of the dental molded cured product obtained by using it. The organic composite filler constituting the composition of the present invention is obtained by polymerizing a sulfonic acid monomer or a sulfonate monomer and one or more other polymerizable vinyl monomers in a polymerization system in which an inorganic compound is dispersed. The manufacturing method is not particularly limited. To give an example of a preferred production method, under temperature conditions within a range that does not cause a thermal polymerization reaction,
After suspending and dispersing the vinyl monomer and inorganic compound in an aqueous medium, by adding a sulfonic acid monomer or a sulfonate monomer and stirring,
Examples include a method in which an aqueous heterogeneous polymerization reaction is caused and the polymerization is carried out for a predetermined period of time. The specific sulfonic acid monomer or sulfonate monomer represented by the above general formula [] used for forming the organic composite filler of the present invention has a sulfonic acid group as an active site that brings about polymerization activity, and The presence of a double bond as an active site that expresses strong union between the polymer and the inorganic compound is essential, and any compound having a structural formula containing these functional groups can be applied. Acrylamido-2-methylpropanesulfonic acid (hereinafter referred to as AMPS), sodium 2-methacrylethanesulfonate (hereinafter referred to as
SEM・Na), 3-sodium methacrylicpropanesulfonate (hereinafter abbreviated as SPS), 2
-Sodium propenesulfonate (hereinafter referred to as NaAS)
(hereinafter referred to as "NaMS"), sodium 2-methyl-2-propenesulfonate (hereinafter referred to as "NaMS"), etc., but AMPS containing an amide bond, SEM/Na containing an ester bond, and SPS are particularly notable for secondary aggregation. It is preferable because it exhibits performance and has extremely high polymerization activity. In addition, the inorganic compounds used in the production of the organic composite filler of the present invention include those according to the periodic law,
, group metals, transition metals and their oxides, hydroxides, chlorides, sulfates, sulfites, carbonates, phosphates, silicates, and mixtures and complex salts of these metals, among which barium sulfate , silicon dioxide, aluminum oxide, titanium oxide, talc, quartz powder, glass powder, glass beads, glass fiber, barium salt, glass filler containing lead salt, silica gel, carbon fiber, zirconium oxide, tin oxide, vinyl The activation of the monomer and the strong coalescence effect with the polymer are particularly remarkable and preferred. One of the major features of the present invention is that it can be applied to inorganic compounds for which ordinary coupling treatment is not effective, and the shape and size of the inorganic compound can also be selected. Further, as the vinyl monomer used in the production of the organic composite filler of the present invention, any ordinary vinyl monomer that can be radically polymerized can be used.
Among them, methyl methacrylate is particularly preferable because it has a specifically high polymerizability and good cohesiveness between the produced polymer and the inorganic compound. When using a mixture of two or more types of monomers, using methyl methacrylate as one component can be said to be a preferable application method, especially from the viewpoint of polymerization activity. Incidentally, during the polymerization, a radical polymerization initiator such as benzoyl peroxide, azobisisobutyronitrile, potassium persulfate, etc. can be used as necessary. The concentration of the sulfonic acid monomer or sulfonate monomer when obtaining the organic composite filler is approximately 0.05 to 0.05 based on the total weight of the inorganic compound and vinyl monomer.
It is used in an amount of 100% by weight, preferably from 0.1 to 50% by weight, particularly preferably from 0.5 to 30% by weight. In most cases, it is preferred to increase the amount of sulfonic acid or sulfonate monomer as the vinyl monomer content increases. The weight ratio of vinyl monomer or mixture thereof to inorganic compounds used can vary within a wide range and is from about 500:1 to 1:5, preferably from about 50:1 to about 1:1. The amount of water is about 1% to several hundred times, preferably about 10 times, based on the total weight of the inorganic compound and vinyl monomer.
%~10 times. The reaction is preferably carried out under an atmosphere of an inert gas, such as nitrogen, at a temperature of about 10 to
It is carried out at 100°C, preferably 20-80°C. The specific reaction temperature here is selected as appropriate depending on the vinyl monomer used, but it is important to carry out the reaction at a temperature that suppresses thermal polymerization to a negligible level, and does not cause extreme thermal polymerization. When carried out at high temperatures, the integrity and uniformity of the resulting composite filler is inhibited. Reaction time is 30 minutes to about 15 hours. The produced organic composite filler has a temperature of about 10 to 300℃, preferably about 50℃.
Can be dried at a temperature range of ~200℃. still,
The interaction between the surface of the inorganic compound and the polymer applied by the method of the invention goes beyond simple adsorption or adhesion in the physical sense of van der Waalska et al. This is clear from the fact that a large amount of unextracted polymer is observed even after extraction with a good solvent for vinyl polymer. The vinyl compound blended with the organic composite filler to form the composition of the present invention may be a monofunctional vinyl compound or a polyfunctional vinyl compound. Examples of monofunctional vinyl compounds include styrene, acrylonitrile, vinyl acetate, methyl acrylate and methacrylate, ethyl acrylate and methacrylate,
Examples include butyl acrylate and methacrylate, hydroxyethyl acrylate and methacrylate, methoxyethyl acrylate and methacrylate, glycidyl acrylate and methacrylate, methacryloyloxyethyl trimellitic acid and its acid anhydride. In addition, examples of polyfunctional vinyl compounds include the following general formula: (In the formula, R ₅ is a hydrogen atom or a methyl group, and P is an integer of 1 to 20.) Acrylates and methacrylates, 1,4-butanediol diacrylate and methacrylate, 1,3-butanediol diacrylate and methacrylate, 1,6-hexanediol diacrylate and methacrylate, glycerin diacrylate and methacrylate, and the following general formula (In the formula, R ₅ is a hydrogen atom or a methyl group, and p is an integer of 1 to 20.) , pentaerythritol tetraacrylate and methacrylate, bisphenol A diacrylate and methacrylate, and the like. These acrylates and methacrylates are
One type thereof may be used or two or more types may be used in combination. Furthermore, it is preferable that these vinyl compounds be blended in an amount of 0.001 to 100 times (by weight) the amount of the above-mentioned composite filler. If the amount of the vinyl compound used is outside the above range, it will be difficult to form a dental composition successfully. The dental composition of the present invention is composed of a mixture of an organic composite filler obtained by using the sulfonic acid monomer or sulfonate monomer as a polymerization initiator and a vinyl compound that is a raw material for producing a matrix resin. Used as dental material,
In obtaining a desired cured molded product, it is preferable to use a polymerization initiator for polymerizing and curing the vinyl compound, although it depends on the type of vinyl compound used. As the polymerization initiator, any known compound can be used, but in the case of heat curing, substances that can decompose at high temperatures and initiate polymerization, such as benzoyl peroxide, cumene hydroperoxide, t-butyl These include hydroperoxide, dicumyl peroxide, acetyl peroxide, lauroyl peroxide, and azobisisobutyronitrile.
Further, in the case of polymerization and curing at room temperature, for example, a combination of peroxide and amines, peroxide and sulfinic acids, or peroxide and cobalt compounds can be used. When using a combination of polymerization initiators, the composition of the present invention can be divided into two parts, one containing peroxide and the other containing amines, sulfinic acids, or cobalt compounds. . When using a combination of polymerization initiators, the composition of the present invention can be divided into two parts, one containing the peroxide, and the other containing amines, sulfinic acids, or cobalt compounds. The composition of the present invention may also be prepared by using a photosensitizer such as benzoimethyl ether, benzoiethyl ether, benzoipropyl ether, etc.
It can also be cured by ultraviolet irradiation. The amount of polymerization initiator used to cure the composition of the present invention is 0.05 to 10% by weight based on the vinyl monomer.
It is. The composition of the present invention may also contain colorants, polymerization inhibitors, ultraviolet absorbers, oxidation stabilizers, and the like, if necessary. The composition for dental materials according to the present invention contains an organic composite filler in which an inorganic compound and an organic polymer are strongly integrated, so that the interfacial affinity between the inorganic filler and the organic resin is improved. Due to this remarkable improvement, the cured product obtained by curing this material has high hardness, mechanical properties, and excellent appearance that cannot be obtained with conventional dental materials. Next, the present invention will be explained in more detail with reference to Examples. Note that parts in the examples indicate parts by weight. Example 1, Comparative Examples 1 and 2 Silicon dioxide powder (manufactured by Fuji Davison Chemical Co., Ltd., 38.7 g of Cyroid (trade name: 266) was suspended and dispersed in 270 ml of deionized water, and the mixture was purged with nitrogen for 30 minutes. Next, 30.0 g of methyl methacrylate as a vinyl monomer was added under nitrogen flow and vigorous stirring. Next, add the above reaction solution in a hot water bath.
After raising the temperature to 50°C and confirming that the added monomer was uniformly dispersed, a solution of 6.5 g of SEK/Na dissolved in 10 ml of deionized water as a sulfonate monomer was gradually added, and the mixture was heated at the same temperature for 8 hours. A polymerization reaction was carried out. After the reaction was completed, the product was filtered under reduced pressure, thoroughly washed with deionized water, and then dried with hot air at 100°C to remove moisture, yielding 67.7 g of an organic composite filler. This composite filler has a polymer content of 41% as measured by a calcination method, and when a 50-hour Soxhlet extraction test was conducted using hot benzene as an extraction solvent, the polymer content after the extraction process was 32%.
%, it was found that the surface of the silicon dioxide powder and most of the polymer composited by this method were extremely strongly integrated. The thus obtained composite filler, a mixed solution of polymethyl methacrylate powder (manufactured by Mitsubishi Rayon Co., Ltd., trade name Acrycon AC) and methyl methacrylate monomer (weight ratio = 2:1), triethylene glycol dimethacrylate and Benzoyl peroxide was blended in the proportions shown in Table 1, the mixture was mixed mechanically, filled into a plaster mold, and dry cured at 60°C for 3 hours and then at 100°C for 1 hour. After curing, 24
After being stored in water at 37°C for an hour, it was used as a sample for measuring physical properties. Table 1 shows the compressive strength and indirect tensile strength of the cured product. For comparison, when silicon dioxide powder was treated with a silane coupling agent (with 3-methacryloyloxypropyltrimethoxysilane) instead of the composite filler according to the present invention, the untreated silicon dioxide powder was Similar evaluations were also conducted for the case where the compounds were blended.

[Table] As is clear from Table 1, the composite filler according to the present invention has superior mechanical properties compared to dental materials made of conventionally used silane-treated fillers and untreated fillers. It can be seen that a cured product having the following properties can be obtained. In addition, the composite filler according to the present invention has extremely good wettability with the liquid resin, so it is easy to composite, and the appearance of the prepared cured test piece is
It was significantly cleaner than the comparative example. Example 2, Comparative Examples 3 to 4 In Example 1, polymethyl methacrylate-
Powder-liquid polymerization was carried out in the same manner as in Example 1, except that bisphenol A diglycidyl methacrylate was used instead of the methyl methacrylate monomer mixture, and the compressive strength and indirect tensile strength of the resulting composition were measured. The results are shown in Table 2.

[Table] As is clear from Table 2, the untreated filler shown in Comparative Example 4 cannot be used to produce cured specimens, and the conventionally used silanized filler shown in Comparative Example 3 cannot be used. While the strength properties are at extremely low levels, the composite filler produced by the method of the present invention has
It can be seen that the cured product for dental materials has a remarkable strength-improving effect and has excellent mechanical properties. Example 3, Comparative Example 5 38.7 g of aluminum oxide powder (special grade reagent) as an inorganic compound was subjected to an aqueous heterogeneous polymerization reaction in the same manner as in Example 1 to obtain 63.5 g of an organic composite filler. Such composite fillers have a polymer content of 28%
The polymer content after extraction treatment was 23%. The composite filler thus obtained was blended in the same manner as in Example 2, and the mechanical strength of the cured product was measured. The results are shown in Table 3.

[Table] As is clear from Table 3, the strength properties of the untreated filler shown in Comparative Example 5 are at extremely low levels, whereas the composite filler obtained by the method of the present invention has Provides a cured material for dental materials that has a remarkable strength improvement effect and excellent mechanical properties. Furthermore, the composite filler according to the present invention has extremely good wettability with the liquid resin, so it is easy to form a composite, and the appearance of the prepared cured test pieces was significantly cleaner than that of the comparative example. Example 4, Comparative Example 6 38.7 g of barium sulfate powder (special grade reagent) as an inorganic compound was subjected to an aqueous heterogeneous polymerization reaction in the same manner as in Example 1 to obtain 65.0 g of an organic composite filler. Such a composite filler has a polymer content of 29%
The polymer content after extraction treatment was 25%. The thus obtained composite filler was blended in the same proportion as in Example 3, and the mechanical strength of the cured product was measured. The results are shown in Table 4.

[Table] As is clear from Table 4, the untreated filler shown in Comparative Example 6 cannot produce cured test pieces, whereas the cured test pieces of the composite filler according to the present invention are extremely clean. A cured product for dental materials which has a good appearance and excellent mechanical properties was obtained. Example 5 A cured product was obtained in the same manner as in Example 1 except that SPS was used instead of SEM.Na as the sulfonic acid monomer. Compressive strength of cured product is 1895Kg
f/cm ² , and the indirect tensile strength was 445 Kgf/cm ² . Moreover, the appearance of the cured test piece was significantly cleaner than those of Comparative Examples 1 and 2. Example 6 A cured product was obtained in the same manner as in Example 1 except that AMPS was used instead of SEM.Na as the sulfonic acid monomer. Compressive strength of cured product is 1860
Kgf/cm ² , and the indirect tensile strength was 440 Kgf/cm ² . Moreover, the appearance of the cured test piece was significantly cleaner than that of Comparative Examples 1 and 2.

Claims (1)

[Claims] 1. The following general formula (In the formula, R ₁ is H, an alkyl group having 1 to 20 carbon atoms,
X is -CONH-, [Formula] -COO (CH ₂ -) _n , or -(CH ₂ )- _o , R ₂ and R ₃ are each H or an alkyl group having 1 to 15 carbon atoms, R ₄
is an alkylene group having 1 to 15 carbon atoms, m is an integer of 1 to 20, n is an integer of 0 to 20, and Y is H, NH ₄ or an alkali metal atom). A dental composition comprising a vinyl compound and an organic composite filler obtained by polymerizing a monomer and at least one other radically polymerizable vinyl monomer in a polymerization system in which an inorganic compound is dispersed. 2. Claims characterized in that the sulfonic acid monomer or sulfonate monomer is 2-acrylamido-2-methylpropanesulfonic acid, sodium 2-methacrylethanesulfonate, or sodium 3-methacrylpropanesulfonate The dental composition according to item 1. 3. The dental composition according to claim 1, wherein the vinyl monomer is mainly composed of methyl methacrylate.