JP5722139B2 - Method for producing polymerizable composition - Google Patents

Description

  The present invention relates to a method for producing a polymerizable composition in which a powdery filler and a liquid monomer are kneaded to produce a dental restoration material or the like.

For restoration of teeth damaged by caries, fractures, etc., a dental restoration made of a mixture of liquid monomer and powdered filler, called composite resin, is widely used due to its ease of operation. . In the restoration of a tooth by such a dental restoration material, in order to obtain high aesthetics, the surface of the restoration portion by the dental restoration material can be colored using a color tone adjusting material and color-matched with surrounding teeth. is there. Here, the color tone adjusting material is a composition in which a pigment is blended so that a desired coloring can be applied to a dental restoration material composed of a kneaded product of the liquid monomer and the powder filler. In addition, in order to reduce the viscosity so that it can be easily applied, the amount of liquid monomer added is increased with respect to the powdery filler.
By the way, the color tone of a tooth has various individual differences, and in order to express this, it is necessary to prepare many types of the color tone adjusting material by changing the type and amount of the pigment to be blended. Since the amount used for each individual color tone is extremely small, in order to produce these efficiently, a kneaded product with a liquid monomer having a high content of powdery filler is first produced as a kneading base material for dilution, and this is used. It is preferable to distribute the required color tones and add and mix the desired pigment and the liquid monomer required for viscosity reduction into each distribution and knead to dilute each color adjusting material having a different color.

Thus, the kneading of the liquid monomer and the powdery filler is often performed using a “propeller-type stirrer” which is a general-purpose kneader. In other words, if a powdered filler and a liquid monomer are put into a propeller-type stirrer and kneaded to produce a kneading base material for dilution, it is difficult to obtain a desired high content all at once by preparing the initial powdery filler. Therefore, it is manufactured by repeatedly adding filler during kneading. Similarly, it is difficult to dilute to the desired viscosity at the initial charge of the liquid monomer in the production of the color tone adjusting material from the distribution of the kneading base material for dilution, so the monomer is repeatedly added during kneading. To manufacture.
However, the kneading base material for dilution with a high content of powdery filler is a considerably hard paste, and it takes a long kneading time to disperse the liquid monomer again. Propeller-type stirrers are suitable for stirring large-capacity kneaded materials, but not suitable for stirring small-capacity materials. It is not suitable for cases where the amount of use is extremely small and it is necessary to make many kinds of different colors. From these, the process of manufacturing each color tone adjusting material from the dilution kneading base material has a problem in productivity.

On the other hand, in Patent Document 1, a material to be kneaded such as a solder paste, a dental impression material, a paint or a powdery drug is held in a container holder in a state where the container is held, and the container is rotated and rotated. It is disclosed that stirring and defoaming is performed by a stirring and defoaming apparatus including:
That is, in this type of stirring and defoaming device, centrifugal force acts on the material to be kneaded in the storage container due to the revolution of the storage container, the material to be kneaded is pressed against the inner wall of the container by the centrifugal force, and further defoamed. The material to be kneaded in the storage container is stirred by the rotation of the storage container.
However, there is no known example in which such a stirring and defoaming apparatus is used for kneading a liquid monomer and a powder filler, and it is further applied to diluting a polymerizable composition containing a high concentration additive. It was also not known.

Japanese Patent No. 3896449

  The present invention has been made in view of such circumstances, and provides a method for efficiently producing a polymerizable composition having a desired filler concentration by kneading a powdery filler and a liquid monomer. With the goal.

In order to achieve the above object, a method for producing a polymerizable composition of the present invention includes a first charging step of charging a liquid monomer and a powdery filler into a first stirring vessel, and a first stirring vessel. The first kneading step of rotating the stirring blade to knead the monomer and filler to obtain the dilution kneading base material containing bubbles, and the dilution kneading base material obtained by the first kneading step A second charging step of collecting the dilution kneading base material and a required amount of liquid monomer into the second stirring container, and rotating and revolving the second stirring container. by kneading Te, saw including a second mixing step of obtaining a kneaded material having a desired filler concentration, the first dilution is obtained by kneading step kneading preform, the bubbles therein from 0.01 to 0. It was containing useless in the content of 2cm ³ / g.
In the first mixing step of the method of manufacturing the above SL polymerizable composition into the stirred vessel during kneading it is preferably carried out while repeating the additional filler.
Furthermore, the filler concentration of the kneading base material for dilution obtained by the first kneading step of the method for producing the polymerizable composition is 50 to 90% by mass with respect to 100% by mass of the monomer and filler in total. Is preferred.
Further, when the filler concentration of the kneading base material for dilution is 50 to 90% by mass with respect to the total of 100% by mass of the monomer and filler, the filler concentration of the kneaded material obtained by the second kneading step is The total amount of the monomer and filler is preferably 5 to 85% by mass (however, it is less than the filler concentration of the dilution kneading base material obtained by the first kneading step).
Furthermore, the polymerizable composition produced by the above production method is preferably a dental restoration material.
In addition, in the second charging step of the method for producing the polymerizable composition, the dental restorative material is a color tone adjusting material by adding a pigment in addition to the kneading base material for dilution and the necessary amount of monomer. Preferably there is.
Further, when the color tone adjusting material is manufactured, in the second charging step of the method for manufacturing the polymerizable composition, the dilution kneading base material is divided into a plurality, and the distribution kneading base material is different for each distributed kneading base material. It is preferable that a plurality of kinds of color tone adjusting materials having different color tones are produced by introducing kinds and / or amounts of pigments.

According to the method for producing a polymerizable composition of the present invention, the first charging step of charging the liquid monomer and the powdery filler into the first stirring vessel, and the stirring blade of the first stirring vessel are rotated. A first kneading step of kneading the monomer and filler to obtain a dilution kneading base material containing bubbles, and the dilution kneading base material obtained by the first kneading step from the first stirring vessel A second charging step of collecting and adding the dilution kneading base material and the required amount of liquid monomer to the second stirring vessel, and rotating and revolving the second stirring vessel to knead and knead containing saw including a second mixing step of obtaining a kneaded material of the filler concentration, the first mixing step dilution kneading the base material obtained by the, the voids inside the 0.01~0.2cm 3 / ^g since an amount to disperse the filler in the kneading member in the second kneading step DOO Ri Na to be able in a short time, in particular, the first mixing step, dilution kneading preform obtained, the voids inside to include in a content of 0.01~0.2cm 3 / ^g By carrying out, the dispersion of the filler in the kneading material in the second kneading step can be further shortened.
Further, in the first kneading step of the method for producing the polymerizable composition, by repeating the addition of the filler in the stirring vessel during kneading, the filler has a high content in the first kneading step. The kneading base material for dilution can be manufactured smoothly.
If the filler concentration is 50 to 90% by mass with respect to the total of 100% by mass of the monomer and the filler, this diluted kneading base material is useful as a base material for producing a dental restoration material.
Furthermore, in the second kneading step, the dilution kneading base material obtained by the first kneading step has a filler concentration less than the filler concentration of the dilution kneading base material obtained by the first kneading step, If it is 5 to 85 mass% with respect to 100 mass% of a total of a monomer and a filler, the dilution can be implemented reliably.
According to such a method for producing a polymerizable composition of the present invention, a dental restorative material can be produced efficiently. In particular, in the second charging step, a color adjusting material can be efficiently produced by adding a pigment in addition to the kneading base material for dilution and the required amount of monomer.
In the second charging step, the color tone adjusting material is produced by distributing the dilution kneading base material into a plurality of parts, and supplying different types and / or amounts of pigment for each of the diluted kneading base materials. Since a plurality of kinds of color tone adjusting materials having different color tones can be easily produced at a time, it is extremely advantageous from the viewpoint of industrial production.

It is the perspective view which looked at the stirring blade of the planetary motion type stirrer used for the manufacturing method of the polymeric composition by embodiment of this invention from diagonally downward. It is a top view of the container for stirring which shows the stirring state of the stirring blade in the planetary motion type stirrer of FIG. It is a schematic sectional drawing of the centrifugal motion type stirrer used for the manufacturing method of the polymeric composition by embodiment of this invention. It is a perspective view which shows the arrangement | positioning state of the rotation container in the centrifugal motion type stirrer of FIG. It is a flowchart of the manufacturing method of the polymeric composition by embodiment of this invention. It is a flowchart of the manufacturing method of the polymeric composition by a comparative example.

  In the production method of the present invention, first, a liquid monomer and a powdery filler are charged into a first stirring vessel (first charging step). The first stirring vessel is a stirrer equipped with a rotatable stirring blade, and the charged monomer and filler are kneaded by rotation of the stirring blade in the stirring vessel (first kneading step). Next, in the production method of the present invention, after the dilution kneading base material obtained in the first kneading step is recovered from the first stirring vessel, the necessary amount of liquid monomer is added to the second stirring vessel. Input (second input step). The second stirring vessel is a stirrer in which the charged material is kneaded by rotation and revolution, and the charged kneading base material and monomer are kneaded by the movement of the vessel to knead with a desired filler concentration. A material is obtained (second kneading step).

  According to such a method, in the second kneading step, the dilution kneading base material obtained in the first kneading step can be diluted uniformly in an extremely short time. More specifically, the dilution kneading base material obtained in the first kneading step is the same as the stirrer used in the first kneading step in the second kneading step, in which the stirring blades rotate. The dilution time can be significantly shortened to 1/3 or less if a general propeller type stirrer is used, compared to the case of using one. Further, in the method of rotating the stirring blade, the dilution force in the second kneading step is also high in comparison with the case of using a planetary motion type stirrer that revolves in addition to the rotation of the stirring blade that is particularly high in the stirring force. Time can usually be shortened to less than one-half.

Therefore, for example, in the case of manufacturing a color tone adjusting material in a dental restorative material, the dilution kneading base material obtained in the first kneading step is distributed to a plurality, and each distributed dilution is performed in the second charging step. By introducing different types and / or amounts of pigments for each kneading base material and diluting the distribution of the kneading base material for dilution, a plurality of types of color tone adjusting materials having different color tones can be efficiently produced. Can be preferable.
In the present invention, in the second kneading step, the reason why the dilution kneading base material is diluted in a short time is not necessarily clear, but can be estimated as follows. That is, since the first kneading step is performed by the rotation of the stirring blades, air is also vigorously bitten during the kneading, and a large number of bubbles are mixed in the obtained dilution kneading base material. It is normal. On the other hand, the stirring vessel used in the second kneading step is of a type in which the vessel rotates and revolves to knead, and the charged material is loaded with a strong centrifugal force due to the rotation and revolution of the vessel. Kneaded in the state of being made. As a result, a number of bubbles contained in the dilution kneading base material are defoamed, but the monomer is quickly dispersed in the base material because the liquid monomer penetrates by replacing this defoamed space. It is thought that it will do.
Therefore, for example, if the diluting kneading base material obtained in the first kneading step is in such a state that no bubbles are mixed in, the second kneading step is rotated as the stirring vessel. Even if it implements using the thing of the system made to revolve, the working time of this process cannot be shortened as much as this invention. For example, the dilution kneading base material obtained in the first kneading step is defoamed under vacuum conditions, and then the second kneading step is carried out using a stirrer in which the charge is kneaded by rotation and revolution. However, the dilution time cannot be reduced sufficiently.

Hereinafter, the first stirring container and the second stirring container used in the production method of the present invention will be described with reference to the drawings.
<First stirring vessel>
The first stirring vessel includes a stirring blade, and a known stirrer for kneading the charged product by rotation thereof can be used without limitation (hereinafter, the stirrer serving as the first stirring vessel is also referred to as “propeller type stirrer”). The stirring blade is normally rotated at a constant speed and in one direction, but may be intermittently rotated or reversely rotated. Alternatively, a plurality of stirring blades may be arranged side by side and rotated reversely to each other, or a protrusion or plate combined with a stirring bar may be attached to the tank side to enhance the shear stress generated by the stirring blades. .
Among such propeller-type stirrers, the stirring power is particularly high in a planetary motion type stirrer in which the stirring blades revolve in addition to rotation. In the present invention, the first kneading step is performed in a shorter time. Therefore, it is most preferably used. A typical embodiment of the planetary motion type stirrer will be described with reference to FIGS. 1 and 2. The planetary motion type stirrer 1 includes an upper power unit 2 and a lower stirring container 3. , A rotating disk 5 is provided inside a main body 6 having a circular cross section, and the rotating disk 5 is supported by a control motor (not shown) so as to be rotatable in the direction of arrow a about a central axis. The rotating disk 5 is provided with a pair of stirring blades 7 and 8, and the stirring blades 7 and 8 are suspended downward from the rotating disk 5. The shafts 7a and 8a penetrating the rotating disk 5 in the vertical direction are disposed away from the center of the rotating disk 5 and face each other. And it can be rotated in the directions of arrows b and c by a control motor (not shown) mounted on the rotating disk 5. The pair of stirring blades 7 and 8 are pentagonal frames of the same shape, the upper part is a triangular shape with the apex facing upward, the lower part is a quadrilateral shape, and the vertical frames 7b and 8b facing each other in the quadrilateral shape, Connecting pieces 7c and 8c that are connected obliquely are provided.

  At the time of stirring, the power unit 2 descends and enters the stirring container 3 to which the stirring blades 7 and 8 are fixed, and the inside of the stirring container 3 is sealed. The rotating disk 5 rotates about the central axis, and simultaneously rotates around the shafts 7a and 8a of the stirring blades 7 and 8 as rotational centers. Therefore, the stirring blades 7 and 8 rotate around the shafts 7 a and 8 a, and at the same time, revolve around the circumference of the rotating disk 5 with the central axis of the rotating disk 5 as the revolution axis, When the agitated material is added, the agitated blades 7 and 8 are used to obtain a kneaded material. As described above, a large number of bubbles are mixed into the kneaded product due to the rotation of the stirring blades 7 and 8 during the stirring.

<Second stirring vessel>
The second stirring container is of a type in which the container is rotated and revolved and kneaded, and the input material is kneaded by applying a strong centrifugal force due to this motion (hereinafter, a stirrer serving as the second stirring container is installed). Called "centrifugal stirrer"). A typical embodiment of the centrifugal motion type agitator will be described with reference to FIGS. 3 and 4. The centrifugal motion type agitator 11 includes a casing 12, and a centrifugal separator 14 is provided in the casing 12. . The centrifuge 14 is provided with a turntable 15 in the center, and the turntable 15 can be rotated around a rotating shaft 17 by a control motor 16. The turntable 15 includes a circular flat plate 15a located on the inner side and an annular inclined portion 15a on the outer peripheral side, and the annular inclined portion 15b has an annular surface inclined outward from the center side of the flat plate 15a. A rotating container 18 is provided in the annular inclined portion 15b, and the rotating container 18 is disposed at the same radius from the rotating shaft 17 of the rotating table 15. In the present embodiment, three bottomed cylinders are equiangularly spaced (120 degrees). A rotating container 18 having a shape is provided.

Each rotary container 18 is provided with a control motor 19, and the rotary container 18 can rotate around a rotation shaft 21. A storage container 22 for storing a material to be stirred can be set inside the rotating container 18. The storage container 22 is provided with a cap 23, and the cap 23 is formed with a number of vent holes 23a.
The center axis of each rotating container 18 is inclined toward the rotating shaft 17 side of the rotating table 15, and when the rotating table 15 rotates, each rotating container 18 rotates by itself as indicated by an arrow d and the rotating table 15. A centrifugal force is applied while revolving around the rotation shaft 17 as shown by an arrow e (FIG. 4).
The casing 12 is formed to be airtight with the outside, and one end of a pipe 25 connected to the decompression device 24 is connected to the ceiling portion 12a. When the decompression device 24 is operated, the inside of the casing is decompressed.
In the method for producing the polymerizable composition of the present embodiment, the polymerizable composition is produced using both the propeller type stirrer and the centrifugal motion type stirrer described above.

[Example]
Hereinafter, a procedure for producing a polymerizable composition will be described using a color tone adjusting material as an example among dental restoration materials.
FIG. 5 is a flow chart for producing a polymerizable composition. First, a planetary motion type agitator 1 shown in FIGS. 1 and 2 is used as a propeller type agitator.
The planetary motion type stirrer 1 uses a planetary mixer (model PLM-15) manufactured by Inoue Seisakusho Co., Ltd. having a stirring vessel capacity of 15 L.
The liquid monomer and the powder filler are put into the stirring container 3 of the planetary motion type stirrer 1. The monomer as the polymerizable monomer used in the present invention is not particularly limited as long as it is liquid at 20 ° C., and generally known monomers having a vinyl group, an allyl group, an acrylic group, a methacryl group or the like as the polymerizable group. Can be used. The viscosity at 23 ° C. is 0.01 to 1000 Pas, more preferably 0.1 to 100 Pas.
If the typical thing of the liquid monomer used by this invention is illustrated, it will be a polymerizable monomer which has an acryl group and / or a methacryl group. In addition, the polymerizable vinyl monomer is a bifunctional or more functional monomer, more preferably a bifunctional to tetrafunctional polymerizable monomer, for reasons such as polymerizability of the monomer and mechanical properties of the obtained cured product. Is preferred. Specific examples include those shown in the following (I) to (III).
(I) Bifunctional polymerizable monomer i) Aromatic compound type 2,2-bis (methacryloyloxyphenyl) propane, 2,2-bis [4- (3-methacryloyloxy) -2-hydroxypropoxyphenyl ] Propane (hereinafter abbreviated as bis-GMA), 2,2-bis (4-methacryloyloxyphenyl) propane, 2,2-bis (4-methacryloyloxypolyethoxyphenyl) propane (hereinafter D-2.6E) Abbreviation), 2,2-bis (4-methacryloyloxydiethoxyphenyl) propane, 2,2-bis (4-methacryloyloxytetraethoxyphenyl) propane, 2,2-bis (4-methacryloyloxypentaethoxyphenyl) ) Propane, 2,2-bis (4-methacryloyloxydipropoxyphenyl) pro 2 (4-methacryloyloxydiethoxyphenyl) -2 (4-methacryloyloxytriethoxyphenyl) propane, 2 (4-methacryloyloxydipropoxyphenyl) -2- (4-methacryloyloxytriethoxyphenyl) propane, 2 , 2-bis (4-methacryloyloxypropoxyphenyl) propane, 2,2-bis (4-methacryloyloxyisopropoxyphenyl) propane and acrylates corresponding to these methacrylates; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, Methacrylates such as 3-chloro-2-hydroxypropyl methacrylate or vinyl monomers having —OH groups such as acrylates corresponding to these methacrylates; Diadducts obtained from addition with diisocyanate compounds having an aromatic group such as tilbenzene and 4,4′-diphenylmethane diisocyanate.
ii) Aliphatic compound type ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate (hereinafter abbreviated as 3G), tetraethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,3-butanediol di Methacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate and acrylates corresponding to these methacrylates; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, etc. Methacrylates or vinyl monomers having —OH groups such as acrylates corresponding to these methacrylates, and hexamethylene Diadducts obtained from adducts with diisocyanate compounds such as diisocyanate, trimethylhexamethylene diisocyanate, diisocyanate methylcyclohexane, isophorone diisocyanate, methylenebis (4-cyclohexylisocyanate); 1,2-bis (3-methacryloyloxy-2-hydroxy Propoxy) ethyl and the like.
(II) Trifunctional polymerizable monomer Methacrylates such as trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol trimethacrylate, trimethylolmethane trimethacrylate, and acrylates corresponding to these methacrylates.
(III) Tetrafunctional polymerizable monomer Pentaerythritol tetramethacrylate, pentaerythritol tetraacrylate and diisocyanate methylbenzene, diisocyanate methylcyclohexane, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, methylenebis (4-cyclohexylisocyanate), 4 Diadduct obtained from an adduct of a diisocyanate compound such as 1,4-diphenylmethane diisocyanate and tolylene-2,4-diisocyanate and glycidol dimethacrylate.
These polyfunctional (meth) acrylate polymerizable monomers may be used in combination of a plurality of types as required.
Further, if necessary, monofunctional (meth) acrylate-based monomethacrylates such as methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hydroxyethyl methacrylate, tetrahydrofurfuryl methacrylate, glycidyl methacrylate, and acrylates corresponding to these methacrylates. A polymerizable monomer other than the above-mentioned (meth) acrylate monomer may be used.
In this embodiment, a polymerizable monomer obtained by mixing bis-GMA and 3G at a ratio of 6 to 4 was used (viscosity at 23 ° C., 0.8 Pas).

If the filler used for this invention is a powder form, it will not restrict | limit in particular, The well-known thing used for a dental restoration material etc. can be used without a restriction | limiting. An average particle diameter of 0.001 to 100 μm, more preferably 0.01 to 10 μm can be used.
Specifically, a surface treated product using an inorganic powder such as amorphous silica, silica-zirconia, silica-titania, quartz, alumina, barium glass, zirconia, titania, lanthanoid, colloidal silica, or a silane coupling agent thereof. Organic powders and organic-inorganic composite powders are used, and spherical composite oxides that can be produced by the methods described in, for example, JP-A Nos. 58-110414 and 58-156524 are particularly preferable.
In the present embodiment, spherical silica zirconia having an average particle diameter of 0.4 μm and spherical silica titania having an average particle diameter of 0.08 μm mixed at a ratio of 7 to 3 were used.

In addition to the monomer and filler, the dental restorative material contains a polymerization initiator for curing the monomer. The polymerization initiator can be used without any limitation as long as it can polymerize and cure the polymerizable monomer, and a known polymerization initiator can be used. As polymerization initiators used in the dental field, there are chemical polymerization initiators (room temperature redox initiators), photopolymerization initiators, thermal polymerization initiators, etc., but taking into account curing in the oral cavity, chemical polymerization initiators And / or a photoinitiator is preferable. Further, as other blending materials, a fluorescent pigment, a dye, an ultraviolet absorber, a polymerization inhibitor, and the like may be blended in necessary amounts to prevent discoloration with respect to ultraviolet rays. In this embodiment, camphorquinone and ethyl dimethylaminobenzoate were blended in effective amounts as a polymerization initiator.
In addition, these compounding components other than the monomer and filler may be charged into a stirring vessel in the second charging step described later and kneaded in the second kneading step.

  As shown in the flowchart of FIG. 5, when the liquid monomer and the powdery filler are charged into the stirring vessel 3 of the planetary motion stirrer 1 (step A: first charging step), kneading by the planetary motion stirrer 1 is performed. Begin. That is, the rotating disk 5 of the main body and the stirring blades 7 and 8 are rotated by a control motor (not shown). The agitation blades 7 and 8 agitate the monomer, the filler, and other additives, and knead the monomer and the filler by rotation with the rotation axes 7 a and 8 a as the central axis and revolution by rotation of the rotation disk 5. (Process B: 1st kneading process). The monomer and filler are stirred by the rotation of the stirring blades 7 and 8 due to the rotation and revolution. In the present embodiment, the rotational speed of the rotating disk 5 is 8 to 36 rpm, and the rotational speeds of the stirring blades 7 and 8 are 24 to 96 rpm, but this differs depending on the material and working conditions. In the present embodiment, the number of rotations was appropriately changed in the above range while confirming the state (hardness) of the paste.

When obtaining a kneading base material for dilution of a dental restorative material such as a color tone adjusting material, the filler concentration is preferably 50 to 90% by mass with respect to 100% by mass in total of the monomer and filler, and is 55 to 85% by mass. Is more preferable. However, when such an amount of filler is initially put into the stirring vessel 3 at a time, the filler becomes difficult to disperse even with a planetary motion stirrer having a high stirring power. For this reason, the first filler is charged into the stirring container 3 at 40 mass% to 70 mass% with respect to the total of 100 mass% of the monomer and filler, which is easy to stir the filler, It is preferable to repeatedly add to the stirring vessel 3 repeatedly. In this embodiment, 1500 g of the monomer was charged and 3200 g of the filler was charged.
For the work of adding the filler, the operation of the planetary motion stirrer 1 is stopped once and the filler is charged into the stirring vessel 3 (step C: filler adding step), and then the planetary motion stirrer 1 is restarted. It is common to do this. The filler is added approximately 3 to 10 times, depending on the work. In this way, the monomer and filler are stirred while adding the filler as many times as necessary, and these compositions are kneaded until they are in the form of clay (paste) and become a certain kneading hardness (step D). . In this embodiment, after 10 minutes from the start of the initial kneading, 620 g of filler was additionally added and kneaded for 10 minutes, and thereafter, this filler addition operation was repeated three times (the finally obtained kneading base material for dilution) The filler concentration was 79.1% by mass with respect to the total of 100% by mass of the monomer and filler).

When the monomer and filler are in a certain solidified state by the above operation, the operation in the planetary motion type agitator 1 is finished. The kneading degree of the kneaded material obtained by the operation with the planetary motion stirrer 1 from the process A to the process D is measured by measuring the paste hardness with a rheometer (for example, a rheometer CR-500DX-SII manufactured by Sun Science Co., Ltd.). 1-10 kg was preferable, and in this embodiment, it was 4 kg. The operation with the planetary motion stirrer 1 from the process A to the process D takes about 4 to 8 hours. In this embodiment, about 6 hours were spent.
The kneaded material obtained as described above was confirmed to contain bubbles by observation with a laser microscope when air was caught during stirring by the stirring blades 7 and 8. The diameter of each bubble is usually in the range of 5 μm to 1000 μm, but in the present embodiment, it was in the range of 10 μm to 800 μm. Further, it bubbles, 0.01~0.2cm ³ / g, particularly preferably in the state of being contained 0.015~0.15cm ³ / g. By containing bubbles in this manner, the dispersion of the filler in the kneaded material in the second kneading step can be further shortened.
The measurement of the content of bubbles contained in the kneaded material is carried out by measuring the specific gravity of the kneaded material according to the Archimedes method, and setting the air density to 0.0012 g / cm ³ and the volume of air contained in 1 g. Obtained by calculating. In the present embodiment, 0.05 cm ³ / g bubbles were contained inside the kneaded material.

When the operation of the planetary motion stirrer 1 is completed, the clay-like kneading material composed of the monomer and filler is recovered as a dilution kneading base material, and the kneading material is distributed to the storage container 22 removed from the centrifugal motion stirrer 11. At this time, a necessary amount of monomer is added to the storage container 22. In the present embodiment, the centrifugal motion type agitator 11 uses a rotation / revolution mixer “Shintaro Awatori (model ARV-310)” manufactured by Sinky Co., Ltd. having a capacity of the storage container 22 of 250 ml.
The necessary amount of the monomer is such that the filler concentration of the target polymerizable composition is less than the filler concentration of the dilution kneading base material obtained by the first kneading step and is diluted to a desired value. The amount is preferably diluted to a value 5% lower, more preferably at least 10% lower than the filler concentration of the dilution kneading base material obtained by the first kneading step. Generally, the filler concentration is selected from 5 to 85% by mass, and more preferably from 10 to 80% by mass with respect to 100% by mass of the total of the monomer and filler. If it prescribes | regulates with the compounding quantity with respect to 100 mass parts of kneading | mixing materials distributed to the storage container 22, 5.9-900 mass parts is preferable and 12.5-800 mass parts is more preferable. In this embodiment for producing the color tone adjusting material, 150 g of the kneaded material obtained in the operations from Step A to Step D is distributed to the storage container 22 and the same monomer used in Step A is used as the required amount of monomer. 50 g was added. It is preferable that there are a plurality of storage containers 22 because it is possible to cope with the case where it is desired to manufacture multiple grades having different dilution levels and blended component contents at a time. In the present embodiment, the number of storage containers 22 is three, but may be more.

In this embodiment, as a polymerizable composition, a pigment is added simultaneously with the distribution of the kneading material in order to produce a color tone adjusting material. The pigments can be produced in different colors for each storage container 22 in order to produce a plurality of types having different color tones at the same time. Of course, the same color can also be put in each storage container 22 (process E: 2nd charging process).
Thus, when manufacturing a color tone adjusting material, 0.001-10 mass parts is preferable with respect to 100 mass parts of kneading | mixing materials, and, as for the compounding quantity of a pigment, 0.005-5 mass parts is more preferable. As the pigment, any pigment that can be colored can be used without any limitation, and a known colorant can be used. Specifically, white pigments such as titanium oxide, zinc oxide, zirconium oxide, red pigments such as brown, molybdenum red, chromofal red, etc., yellow pigments such as yellow iron oxide, titanium yellow, chromium oxide, chromofal yellow, etc. Examples of the blue pigment include cobalt blue, ultramarine blue, bituminous blue, chromophal blue, and phthalocyanine blue, and examples of the black pigment include black iron oxide and carbon black. In this embodiment, any storage container 22 includes titanium oxide and chromophore. Tar red was added in an amount of 0.5 g with a slight change in the mixing ratio so that the color tone was different for each container.
After the above preparation, the storage container 22 is set (fixed) on the rotating container 18 of the centrifugal agitator 11 and kneaded.

In the centrifugal motion type agitator 11, the turntable 15 causes the storage container 22 to move circularly by the operation of the control motor 16, and rotates the storage container 22 by the operation of the control motor 19. Therefore, the kneading material in the storage container 22 is kneaded by simultaneously applying the centrifugal force due to the turntable 15 and the centrifugal force due to rotation. Specifically, the rotating shaft 21 of the storage container 22 is inclined obliquely upward on the rotating shaft 17 side of the rotary table 15, and the storage container 22 revolves in the circumferential direction of the rotary table 15 while being inclined, The filler is dispersed efficiently. At this time, the inside of the casing 12 is decompressed by the decompression device 24, and the gas inside the kneaded material is defoamed. As described above, since the liquid monomer permeates into the defoamed space, the monomer is dispersed early in the base material, and the working time for kneading with the centrifugal agitator 11 is significantly shortened. Is done. In this embodiment, a kneaded material in which the filler concentration was uniformly diluted to 59.3% by mass with respect to the total of 100% by mass of the monomer and the filler was obtained in about 5 minutes (step F: second kneading). Process).
In addition, although the rotation speed of the turntable 15 is 200-2000 rpm and the rotation speed of the rotation container 18 (storage container 22) is 100-1000 rpm, it changes with materials and working conditions. In the present embodiment, the rotation speed of the turntable 15 is 2000 rpm, and the rotation speed of the rotary container 18 (storage container 22) is 1000 rpm.

When the stirring / dispersion of the monomer, filler and color tone adjusting material by the centrifugal motion type agitator 11 is completed, the kneaded material is recovered from the storage container 22 (step G). In this embodiment, the working time from the process A to the process G was about 6 hours.
By manufacturing in this way, in this embodiment, the conventional manufacturing time (about 12 hours) as in Comparative Example 1 described later is about half (6 hours), and the polymerization is diluted to the desired filler pigment. It has become possible to produce a functional composition. Further, since the paste-like kneaded material can be distributed to the plurality of storage containers 22 in step E, a plurality of color-specific restoration materials can be manufactured at a time by using pigments having different colors. In particular, the present invention is significant when manufacturing a color tone adjusting material that is extremely used and used on the tooth surface.

[Comparative Example 1]
As Comparative Example 1, a procedure of a conventional method for producing a polymerizable composition will be described with reference to FIG.
As shown in FIG. 6, the method for producing a polymerizable composition according to Comparative Example 1 is the same as steps A to D (FIG. 5) in comparison with the method for producing a polymerizable composition of the present embodiment. Description is omitted.
The kneaded product of the monomer and filler is stirred by the planetary motion type stirrer 1 and kneaded until a constant kneading hardness is obtained (step D). The working time until this kneading state is reached takes about 5 hours as in the above embodiment.
In this comparative example, the planetary motion stirrer 1 is also used for the work after Step I. Therefore, pigments of the same kind and blending amount were added to the stirring vessel 3 of the planetary motion type stirrer 1. One color tone is selected and mixed in the pigment (step I).

Next, kneading by the planetary motion type agitator 1 is started. That is, the rotating disk 5 of the main body and the stirring blades 7 and 8 are rotated by a control motor (not shown). The agitation blades 7 and 8 agitate the monomer, the filler, the color tone adjusting material, and the like by the rotation with the rotation axes 7a, 8a as the central axis and the revolution by the rotation of the rotation disk 5 to knead the monomer and the filler ( Step J). The monomer and filler are stirred by the rotation of the stirring blades 7 and 8 due to the rotation and revolution.
In order to gradually lower the filler concentration, a monomer is added to the stirring vessel 3 (step K). When the monomer is added, the planetary agitator 1 is stopped as described above. After several times the monomer has been added to the stirring vessel 3, the pigment is dispersed, and if the filler concentration is diluted to 5 to 85% by weight with respect to 100% by weight of the monomer and filler, the planetary motion type The operation of the agitator 1 is stopped. The kneading time until the filler and pigment are sufficiently dispersed in the kneaded material is about 6 hours. Finally, the kneaded material is recovered from the stirring container 3 (step L).

The working time spent from the process A to the process L in the comparative example is about 12 hours, and the working time from the process A to the process G in the present embodiment is about 6 hours. Twice the work time, which is a significant reduction in this embodiment. Moreover, in this embodiment, since the addition of a monomer is not required like the process K of a comparative example, an apparatus is not stopped on the way during work, and labor can be saved.
[Comparative Example 2]
In this embodiment, it is also conceivable to use a centrifugal motion stirrer 11 instead of the planetary motion stirrer 1 from the beginning of the work in place of the monomer and filler. However, even when an appropriate amount of monomer and filler were stirred with the centrifugal motion stirrer 11 in the initial stage of stirring, the filler was not dispersed. Therefore, the first half of the agitation operation is agitated by the planetary motion type agitator 1 and the kneading is performed by the centrifugal motion type agitator 11 in the second half as usual.
[Comparative Example 3]
In Example 1, the kneading base material for dilution obtained by the operation with the planetary motion stirrer 1 was defoamed under 0.5 mmHg using a separable flask, and substantially free of bubbles (0.001 cm ³ / G), and this was carried out in the same manner as in Example 1 except that this was used as a kneading base material for dilution of the color tone adjusting material using the centrifugal motion type stirrer 11. As a result, in Example 1, a kneaded product that was uniformly diluted in about 5 minutes in Step F: second kneading step was obtained, but in this comparative example, after 5 minutes, the mass of the kneaded material was Existed. Then, the inside of the storage container 22 was stirred using a spatula, and when the color tone adjusting material was stirred and dispersed using the centrifugal motion type agitator 11 for 2 minutes, a uniformly diluted color tone adjusting material was obtained. . Including the stirring by the spatula and the additional stirring using the centrifugal motion type stirrer 11, an additional time of about 10 minutes was required.

The present invention has been described in detail based on the embodiments with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and other modifications can be made without departing from the scope of the present invention. Or it can be changed.
For example, in the above embodiment, the production of the color tone adjusting material is taken as an example, but the present invention can also be applied to dental restoration materials other than the color tone adjusting material, and kneading of monomers and fillers other than the dental material. is there.

1 Planetary motion type agitator 3 Container for stirring (first stirring container)
DESCRIPTION OF SYMBOLS 4 Rotating plate 6 Main body 7,8 Agitation blade 11 Centrifugal motion type agitator 12 Casing 14 Centrifugal separator 18 Rotating container 22 Storage container (second agitating container)
24 Pressure reducing device

Claims (7)

A first charging step of charging a liquid monomer and a powdery filler into a first stirring vessel;
A first kneading step of rotating a stirring blade of the first stirring vessel to knead the monomer and filler to obtain a kneading base material for dilution containing bubbles;
The dilution kneading base material obtained by the first kneading step is recovered from the first stirring vessel, and the dilution kneading base material and a required amount of liquid monomer are charged into the second stirring vessel. 2 input processes;
The second rotation of the stirring vessel, and kneaded by revolving, seen including a second mixing step of obtaining a kneaded material having a desired filler concentration,
The manufacturing method of the polymeric composition in which the kneading | mixing base material for dilution obtained by the said 1st kneading process contains a bubble with content of 0.01-0.2 cm < ³ > / g inside . The method for producing a polymerizable composition according to claim 1, wherein in the first kneading step, the filler is repeatedly added to the stirring vessel being kneaded. The polymerizable composition according to claim 1 or 2 , wherein a filler concentration of the dilution kneading base material obtained by the first kneading step is 50 to 90% by mass with respect to 100% by mass of the total of the monomer and the filler. Production method. The filler concentration of the kneaded material obtained by the second kneading step is 5 to 85% by mass with respect to the total of 100% by mass of the monomer and filler (however, the filler concentration of the kneading base material for dilution obtained by the first kneading step) The method for producing a polymerizable composition according to claim 3, wherein The manufacturing method of the polymeric composition of any one of Claims 1-4 whose polymeric composition manufactured is a dental restoration material. The polymerizable composition according to claim 4 , wherein, in the second charging step, a color tone adjusting material is produced as a dental restoration material by adding a pigment in addition to the kneading base material for dilution and a necessary amount of monomer. Manufacturing method. In the second charging step, a plurality of dilution kneading base materials are distributed, and different types and / or amounts of pigment are added to each of the distributed dilution kneading base materials, so that a plurality of types of color tone adjusting materials having different color tones are provided. The manufacturing method of the polymeric composition of Claim 4 which manufactures.

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