JPH04210609A - Production of composite material for dental use - Google Patents

Abstract

PURPOSE:To obtain the subject composite material having remarkably improved formability without losing the characteristic features of the original material by simultaneously surface-treating a spherical inorganic filler and an ultrafine particulate inorganic filter and compounding the treated fillers with a polymerizable vinyl monomer and a polymerization initiator. CONSTITUTION:The objective material can be produced by compounding (A) 10-60 pts.wt. of a polymerizable vinyl monomer, (B) 90-40 pts.wt. of powdery fillers composed of (B1) 10 or more wt.% of a spherical inorganic filler having an average particle size of 0.1-1mu and treated with a compound reactive with surface hydroxyl group (preferably a silane coupling agent) and (B2) 0.01 or more wt.% (preferably 0.1-30 pts.wt. per 100 pts.wt. of the component B1) of an ultrafine particulate inorganic filler having an average particle size of 10-50nm and treated with the above component simultaneous to the treatment of the component B1 and (C) 0.001-5wt.% (based on the total material) of a polymerization initiator. The composite material has a fluidity adjusted to optimum level and excellent mechanical strength and gives a polished surface having high lubricity.

Description

[Detailed description of the invention]

[00013

[Industrial Field of Application] The present invention relates to a method for manufacturing dental composite materials. [0002] [Prior Art] Conventionally, composite materials have been produced in which a polymerizable vinyl monomer is mixed with an inorganic or organic filler or an inorganic-organic composite filler in order to improve scientific and engineering properties and reduce volume shrinkage during polymerization. is widely used in the field of dentistry. For example, 2,2-
Acrylic monomer whose main component is bis(4-(3-methacryloxy)-2-hydroxypropoxyphenyl)propane (addition product of bisphenol A and glycidyl methacrylate), quartz or strontium glass with a particle size of several tens of microns. Composite materials have generally been used in which a large amount of pulverized materials such as B. Fillers of various shapes and sizes have come to be used. Shapes include irregular shapes, rods, and spheres, and the sizes range from several nanometers to tens of micrometers. Among them, spherical fillers are the smallest. Because it has a specific surface area of When a spherical filler is used, the polished surface becomes smooth, resulting in a composite material with excellent aesthetics. [0004] In general, the properties required for dental composite materials include sufficient mechanical strength, color tone, and surface properties. These include excellent lubricity and the ability to maintain it in the oral cavity over time, but the most essential thing is excellent operation that is easy for the surgeon to handle and easily achieves his or her goals. The most important property that influences operability is the ability to give the shape to the operator as desired, so-called excellent illumination properties.The present invention Good illuminance means that the shape once given does not collapse at intra-oral temperature or room temperature.Poor illumination means that the shape given under the above conditions collapses over time. In addition, when it is necessary to fill every corner of a cavity, such as with a composite resin for repair, appropriate fluidity is required as well as giving shape, so it is necessary not only to have good illumination properties, but also to It is necessary to adjust the fluidity to the optimum. [0005] The features of dental composite materials containing submicron spherical fillers as a main component include that excellent mechanical strength can be obtained due to the increased filler content; It has excellent surface smoothness, excellent transparency by selecting an appropriate refractive index, and excellent color tone compatibility.However, on the other hand, it has the disadvantages of poor illumination and difficulty in forming shapes. [0006] Generally, the surface of the filler is chemically treated to improve chemical bonding or wetting with the resin matrix for the purpose of increasing the mechanical strength of the composite material. Generally, treatment with a silane coupling agent is commonly performed. Such surface treatment improves wetting at the interface between the filler and matrix monomer and improves mechanical strength, but on the other hand, frictional force decreases and the fluidity of the paste increases. [0007] In particular, when the main component is a submicron spherical filler, the flow of the filler that has started to move due to external force or gravity cannot be stopped, resulting in poor illumination properties. Of course, by making the surface of the filler hydrophilic or otherwise improving its wettability with the matrix monomer, the frictional force at the filler-matrix monomer interface can be increased, and even submicron spherical fillers can improve the illumination properties. However, in that case, the mechanical properties of the cured product are greatly reduced, so it cannot be used in practice. Also, by mixing large amorphous fillers, it is possible to stop the flow of submicron spherical fillers.
It is necessary to insert an irregularly shaped filler in an amount and size larger than a certain amount, which results in a decrease in mechanical strength and the loss of the characteristics of submicron spherical fillers. Therefore, attempts were made to stop the flow of the paste by adding ultrafine inorganic fillers smaller than submicron spherical fillers, but ultrafine inorganic fillers with hydrophobic surfaces were ineffective, and Although the ultrafine particulate inorganic filler is initially effective, it begins to flow over time and the effect disappears. [0008]

[Problems to be Solved by the Invention] As described above, it is possible to improve the illumination properties and fluidity of a dental composite material containing submicron spherical filler as a main component without losing the characteristics of the material itself. Optimal adjustment has become an important technical issue. [0009]

[Means for solving the problem] The present researchers have conducted extensive research with the aim of solving the above technical problem. As a result, it was discovered that the above technical problem could be solved by simultaneously surface treating a submicron spherical inorganic filler and an ultrafine particulate inorganic filler, and the present invention was completed. [00101 That is, the present invention comprises (a) 10 to 60 parts by weight of a polymerizable vinyl monomer, (b) an average particle size of 0.1
90 to 40 parts by weight of a powdered filler containing 10% by weight or more of a spherical inorganic filler of ~1 μm and 0.01% by weight or more of an ultrafine particulate inorganic filler with an average particle size of 10 to 50 nm, and (c) 0.001 parts by weight of all materials. A method for producing a dental composite material containing ~5% by weight of a polymerization initiator, characterized by simultaneously surface-treating a spherical inorganic filler and an ultrafine particulate inorganic filler with a compound that reacts with the surface hydroxyl group of the filler. This is the above manufacturing method. [0011] One component of the dental composite material of the present invention is a polymerizable vinyl monomer. The vinyl monomer is not particularly limited, and generally known ones can be used. A typical example that is generally preferably used is a polymerizable monomer having an acrylic group/methacrylic group. Specific examples are as follows. [0012] Monofunctional vinyl monomers include methacrylate monomers such as methyl methacrylate, ethyl methacrylate, and hydroxyethyl methacrylate, and acrylate monomers such as their acrylates. [0013] Difunctional vinyl monomers include 2,2-bis(4-(3-methacryloxy)-2-hydroxypropoxyproboxyphenyl)propane, 2,2-bis(
4-methacryloxyethoxyphenyl)propane, 2.
2-bis(4-methacryloxypolyethoxypolyethoxyphenyl)propane and their acrylates; 2
- Aromatic systems obtained from the addition of vinyl monomers containing OH groups, such as hydroxyethyl methacrylate or these acrylates, with diisocyanate compounds containing aromatic groups, such as diisocyanate methylbenzene, 4,4' diphenylmethane diisocyanate. Sheaduct compound ethylene glycol dimethacrylate;
diethylene glycol dimethacrylate; triethylene glycol dimethacrylate; neopentyl glycol dimethacrylate; 1,6-hexanethiol dimethacrylate and these acrylates; Mention may be made of aliphatic sheaduct compounds obtained from addition with diisocyanate compounds such as methylene diisocyanate and methylene bis(4-cyclohexyl isocyanate). [0014] Trifunctional vinyl monomers include trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, trimethylolmethane trimethacrylate and their acrylates; tetrafunctional vinyl monomers include pentaerythritol tetramethacrylate, pentaerythritol tetraacrylate and trilene- Examples include sheaduct compounds obtained from the addition of a diisocyanate compound such as 2,4-diisocyanate and glycidol dimethacrylate. In addition to the vinyl monomers of 00153 and above, those generally known for industrial use can be used. In general, vinyl esters, vinyl ethers, alkenylbenzenes, etc. are preferably used. [00161 In the present invention, the polymerizable vinyl monomer includes not only a single component but also a vinyl monomer mixture consisting of a plurality of vinyl monomers. When using multiple types of polymerizable vinyl monomers, if these monomers have extremely high viscosity at room temperature or are solid, it is preferable to use them in combination with a polymerizable vinyl monomer of low viscosity. This combination is not limited to two types, but may be three or more types. Furthermore, since a polymer consisting only of a monofunctional vinyl monomer does not have a crosslinked structure, the mechanical strength of the polymer generally tends to be poor. for that,
When monofunctional vinyl monomers are used, they are preferably used together with polyfunctional monomers. The most preferred combination of polymerizable vinyl monomers is a method in which an aromatic compound of a difunctional vinyl monomer is used as a main component and an aliphatic compound of a difunctional vinyl monomer is combined. In addition to this, for example, a combination of a difunctional vinyl monomer and a tetrafunctional vinyl monomer, an aromatic compound and an aliphatic compound of a difunctional vinyl monomer, and a trifunctional vinyl monomer and/or
Alternatively, combinations of tetrafunctional vinyl monomers and combinations in which monofunctional vinyl monomers are further added to these combinations can be suitably employed. [0017] Next, although the composition ratio in the combination of the above vinyl monomers may be determined as necessary, the composition ratio that is generally suitably employed will be shown. [0018] (1) 30 to 80% by weight of aromatic compounds and 70 to 2% of aliphatic compounds of the difunctional vinyl monomer
0% by weight (2) 30 to 100% by weight of trifunctional vinyl monomer and 0 to 70% by weight of tetrafunctional vinyl monomer (3) 30 to 60% by weight of aromatic compound and 5% of aliphatic compound of difunctional vinyl monomer ~30% loading, trifunctional vinyl monomer 1
Composition ratios such as 0 to 80% by weight and 0 to 50% by weight of the tetrafunctional vinyl monomer are preferred. [00191 The powder filler used in the present invention must contain both a spherical inorganic filler and an ultrafine particulate inorganic filler, and may optionally contain an inorganic or organic filler (hereinafter referred to as a third filler). can be added. [00201 The spherical inorganic filler may be one having a hydroxyl group on the surface, and among them, inorganic oxides such as silica, alumina, zirconia, and the above-mentioned glasses, and JP-A-58-1
No. 10414, Japanese Unexamined Patent Publication No. 151321/1983,
JP-A-58-152804, JP-A-58-156
524, JP 58-156526, JP 59-54616, JP 59-101409
At least one metal selected from the group consisting of Group 1, Group 1I, Group 1II, and Group tV of the Periodic Table that is capable of bonding with the substances disclosed in each publication of the above publications, that is, silica. Inorganic oxide, silicon nitride, whose main constituents are oxide and silica, and whose particle size is 0.1 μm to 1.0 μm.
Nitrides such as aluminum nitride and titanium nitride, borides such as zirconium boride and titanium boride, and the like are preferably used. [0021] The average particle size of the spherical inorganic filler is 0.1 to
The range is 1 μm. If the particle size is smaller than 0.1 μm, the area of the interface when mixing the filler and the vinyl monomer becomes too large, making it difficult to fill a large amount of the filler into the vinyl monomer. As a result, the mechanical strength of the cured product obtained by polymerizing the composite material decreases. In addition, when the particle size is larger than 1 μm, the polished surface of the cured product obtained by polymerizing the composite material generally becomes rough, resulting in poor aesthetics as a dental composite material. [0022] Generally known ultrafine particulate inorganic fillers are used. Examples include ultrafine aluminum oxide, ultrafine anhydrous silica, and ultrafine titanium oxide. [0023] The average particle size of the ultrafine filler is 10-
The range is 50 nm. If the particle size is smaller than 10 nm, the specific surface area becomes too large and a large amount of surface treatment agent is required, which is not preferable. Furthermore, if the particle size is larger than 50 nm, the illumination properties of the composite material will not be improved and the effects of the present invention will not be obtained. [00241 In addition to the above-mentioned spherical filler and ultrafine particulate inorganic filler, a third filler can be added to the powder filler of the present invention in order to improve mechanical strength, aesthetics, and operability. [0025] The third filler has an average particle size of 0.1
~100μm amorphous inorganic filler, shape not specified, average particle size 0. An organic filler or an organic composite filler having a thickness of 1 to 100 μm is employed. Furthermore, a spherical inorganic filler having an average particle diameter of more than 1 μm and less than 100 μm may be used in some cases. These various types of third fillers can be used alone or in combination depending on the desired physical properties. [0026] Representative examples of the amorphous inorganic filler used as the third filler include inorganic oxides containing silica, such as quartz, cristobalite, eucryptite, spodumene, carneguite, orthoclase, albite, Natural minerals such as anorthite or silica-alumina-calcia-sodium oxide-potassium oxide, silica-alumina-boron oxide-potassium oxide-barium oxide, silica-calcia-boron oxide-sodium oxide-potassium oxide-zinc oxide, silica-alumina Examples include glasses whose main components are sodium-potassium oxide-lead oxide. [0027] Similarly, examples of organic fillers that can be used include monofunctional methacrylate or acrylate polymers such as polymethyl methacrylate and polyethyl acrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and neopentyl glycol dimethacrylate. , 1,6-hexanediol dimethacrylate, 2,2-bis(4-(3methacryloxy)-2-hydroxypropoxyphenyl)propane secondary functional methacrylate polymers or forms in which the methacrylic group is substituted with an acrylic group acrylate polymers, trimethylolpropane trimethacrylate, tetramethylolmethane trimethacrylate, tetramethylolmethanetetramethacrylate, trifunctional or tetrafunctional methacrylate polymers, or acrylate polymers in which the methacrylic group is substituted with an acrylic group. It is also possible to use copolymers of the above polymers. In addition, polycarbonate, polystyrene, polydiallyl phthalate, polydiethylene glycol bisallyl carbonate, etc. can also be used. [0028] Also, It is also possible to fill the above polymer with an inorganic filler to make it an organic composite filler.The organic composite filler is made by uniformly dispersing the inorganic filler used in the present invention in the above polymer. Those having a structure are preferable. [0029] Specific examples of the spherical inorganic filler having a relatively large average particle size exceeding 1 μm include alumina, zirconia, glass beads, etc. [00301 Present invention The polymerization initiator used is generally a known photopolymerization initiator or chemical polymerization initiator without particular limitation. [0031] The photopolymerization initiator can be excited by visible light irradiation of 390 to 700 nm to initiate polymerization. Any known catalyst can be used without any restriction as long as it is suitable. Preferably, a catalyst that initiates polymerization with visible light of 400 to 600 nm is used. In general, as a photopolymerization initiation catalyst, a photosensitizer or a photopolymerization accelerator is used. It is preferable to use it in combination with. Examples of those suitably used as photosensitizers include benzyl, camphorquinone, α-naphthyl, acetonaphcene, P, P'-dimethoxybenzyl, 1,2-phenanthrenequinone, These are α-diketones such as naphthoquinone.The α-diketones used in the present invention can be selected from at least one type of known α-diketones, and can also be used as a mixture of two or more types. Moreover, camphorquinone can be used most preferably. [0032] In addition, as a photopolymerization accelerator, N, N-
dimethylaniline, N, N-diethylaniline, N,
N-Dimethyl-P-toluidine, N, N-diethyl-P-toluidine, P-dimethylaminobenzaldehyde, N. N-dihydroxyethyl-P-toluidine, N-ethyljetanolamine, N,N-dimethylhexylamine, N,N-dimethylaminoethyl methacrylate,
Tertiary amines such as N, N-diethylamino methacrylate; 5-butylbarbylic acid, 1-benzyl-5
Barbylic acids such as phenylbarbituric acid; Ben. yl peroxide, di-t-butyl peroxide, 1
-Organic peroxides such as butyl perbenzoate can be suitably used. At least one of these photopolymerization accelerators
Any species can be selected and used, and two or more species can also be used in combination. [0033] In addition, when tertiary amines are used as accelerators, especially tertiary amines in which a nitrogen atom is directly substituted on an aromatic group are used.
Grade amines are more preferably used. Furthermore, photopolymerization promotion 4
In addition to the tertiary amine, citric acid,
It is effective to add oxycarbonic acids such as malangic acid, tartaric acid, glycolic acid, gluconic acid, α-quaternary diisobutyric acid, 2-hydroxypropanoic acid, 3-hydro-4-sibutanoic acid, and dimethylolpropionic acid. [0034] Typical biochemical synthesis initiators include:
Organic peroxides such as benzoyl peroxide and tertiary amines C
There are combinations. Each is added separately and polymerization is initiated by mixing the harmful components immediately before use,
Let it harden. Further, when curing is performed at a high temperature instead of room temperature, a compound that decomposes at a high temperature to initiate polymerization of the vinyl monomer can also be used. Known organic peroxides can be used without particular limitation. Examples include benzoyl peroxide, fast-brewing lauroyl, t-butyl hydroxy peroxide, di-t-butyl peroxide, and the like. Furthermore, any known tertiary amines may be used without any particular limitation, and those explained in the section of photopolymerization accelerators are generally used. Furthermore, examples of compounds that decompose at high temperatures to initiate polymerization include organic peroxides and 2,2'-azobisisobutyronitrile as exemplified above. (0035) Since the surface of the inorganic filler is hydrophilic,
In order to improve wetting with vinyl monomers, compounds that are reactive with the surface hydroxyl groups of organosilicon compounds (hereinafter referred to as
The surface is treated with a surface treatment material (referred to as a surface treatment material). In the present invention, it is essential to surface-treat the spherical inorganic filler and the ultrafine particulate inorganic filler at the same time. Incidentally, in the present invention, surface treatment at the same time means surface treatment in a state in which both fillers coexist. [0036] If the spherical inorganic filler and the ultrafine particulate inorganic filler are not surface-treated simultaneously but are surface-treated separately, the resulting composite material has poor nail shape and is ineffective. Further, when only either the spherical inorganic filler or the ultrafine particulate inorganic filler is subjected to surface treatment, the mechanical strength of the composite material obtained with the former is low and cannot be used. In the latter case, although the resulting composite material initially has good nail shape, the nail shape deteriorates over time and becomes ineffective. In addition, w of the vinyl monomer contained in the composite material
If the degree is increased, the nail formability is slightly improved, but it is not sufficient, and the filler compounding ratio is lowered, resulting in a decrease in mechanical axiality. [00371 As described above, by simultaneously surface-treating the spherical inorganic filler and the ultrafine scoop-shaped inorganic filler, the nail shape of the composite material containing the spherical inorganic filler can be improved at the initial stage. Generally known surface treatment materials can be used without particular limitation. Examples include alcohol, organic silyl chloride, alkoxysilane, alkoxytitanium, alkoxyaluminum, and the like. Among these, so-called silane coupling agents, which are alkoxysilanes, are preferably used. Typical silane coupling agents include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxy)silane, and γ
-methacryloxypropyltrimethoxysilane and the like. [0038] The method of the above-mentioned surface treatment is not particularly limited except that both fillers are treated at the same time, and a known method can be used. For example, a method is employed in which a mixture of a spherical inorganic filler and an ultrafine particulate inorganic filler is contacted with a solvent such as alcohol in which a surface treatment material is dissolved for a certain period of time, and then the solvent is removed. Here, the spherical inorganic filler and the ultrafine particulate inorganic filler may be mixed in advance, or may be added separately and mixed later. Furthermore, the order in which they are added is not limited. [00393 The mixing method during surface treatment is not particularly limited as long as the spherical inorganic filler and the ultrafine particulate inorganic filler are sufficiently dispersed and mixed, and any known method may be used. Preferably, a wet media mill such as a ball mill is used. [00401 The composition ratio of the dental composite material of the present invention is 10 to 60% by weight of vinyl monomer, 90 to 4% of powdered filler containing spherical inorganic filler and ultrafine particulate inorganic filler.
It is appropriate to set it to 0% by weight. [00413 When the vinyl monomer is less than 10% by weight, it generally does not form into a paste. Also, if the amount is more than 60% by weight, the viscosity of the paste will be too low,
Good nail shape, which is an effect of the present invention, cannot be expected. [0042] Furthermore, the proportion of the spherical inorganic filler contained in the powder filler is preferably 10% by weight or more. Below this range, there are drawbacks such as difficulty in obtaining a high filler content and poor surface gloss of the polished surface. Moreover, since the nail shape is originally good, the meaning of the present invention is lost. Furthermore, the effect of the present invention is greatest when the proportion of the spherical inorganic filler is 30% by weight or more. In this case, a system in which the ultrafine particulate inorganic filler is surface-treated at the same time as the spherical inorganic filler and is not added has high fluidity and poor nail shape, so the present invention fully exhibits its effects. [0043] The proportion of the ultrafine particulate inorganic filler is 0.00 parts by weight based on 100 parts by weight of the spherical inorganic filler. 1 to 30 parts by weight is preferred. The optimum composition ratio depends on the specific surface area of the spherical inorganic filler and the desired fluidity. [0044] The polymerization initiator is appropriately selected from the range of 0.001 to 5% by weight, more preferably 0.01 to 3% by weight based on the total material. [0045] In addition, components such as ultraviolet absorbers such as 2-hydroxy-4-methylbenzophenone, polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, and 2,5-ditertiary-butyl-4-methylphenol, and pigments, It can be optionally added to the dental composite material of the present invention as needed. [0046]

EXAMPLES The present invention will now be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. In addition, the measurement of the particle diameter of the spherical inorganic filler shown in the following production example and the measurement of the nail shape evaluation value of the composite material for photopolymerization: The measurement of "flow" was performed according to the method shown below. [0047] (1) Particle Size Take a scanning electron micrograph of the powder, and calculate the number of particles (n) observed within a unit field of view of the photograph, and the particle diameter (direction C
The diameter Xi) is determined and calculated using the following formula. Number average particle size After 1 hour, the distance the sample has flowed (moving pressure III at the lowest end) is measured, and this is defined as the flow (unit=M). [0049] (3) The compressive strength paste was filled into a stainless steel split mold having holes with a diameter of 4 mm and a depth of 3M. Next, polypropylene films were pressed from both sides, and the tip of a quartz rod of a dental visible light irradiator (White Light, manufactured by Takara Belmont) was closely fixed thereon, and then light was irradiated for 30 seconds. Next, the cured product was taken out from the mold, and the bottom surface of the cured product was irradiated with visible light for 30 seconds. After storing the cured product in water at 37°C for 24 hours, it was compressed with a Tensilon manufactured by Toyo Baldwin Co., Ltd. at a crosshead speed of 10 am/min.
The strength of the fracture is taken as the compressive strength. [00501 In addition, compounds in the following Examples and Comparative Examples are abbreviated as follows. Compound name Abbreviation 2.
2-bis[4-(3-methacryloxy)2-hydroxypropoxyphenyl]propane B
i s -GMA2.2-bis(4-methacryloxypolyethoxyphenyl)propane
B f s -MPEPP triethylene glycol dimethacrylate TEGD
MA neopentyl glycol dimethacrylate
NPCDMA approximately 6:4 mixture of tetramethylolmethane trimethacrylate and tetramethylolmethanetetramethacrylate A-TMM-3L Camphorquinone CQN,
N-dimethyl-P-toluidine D
The MPT [00511 (4) surface roughness paste was filled into a stainless steel split mold having holes with a diameter of 6 mm and a depth of 3 mm. Next, polypropylene films were pressed from both sides, and the tip of a quartz rod of a dental visible light irradiator (White Light, manufactured by Takara Belmont) was closely fixed thereon, and then light was irradiated for 30 seconds. After storing the cured product in water at 37° C. for 24 hours, it was polished with emery paper No. 800, and further puff-polished using toothpaste (White and White, manufactured by Lion Corporation). After cleaning the test piece with an ultrasonic cleaner, the ten-point average roughness of the polished surface was measured using Surfcom 200A manufactured by Tokyo Seimitsu Co., Ltd.
Surface roughness. [0052] Production Example 1 5.0 g of 0.04% hydrochloric acid and tetraethyl silicate (S
Dissolve 176.6 g of i (OC2H5) 4, manufactured by Nippon Colcourt Chemical Co., Ltd., product name: ethyl silicate 28) in 0.44 L of methanol, and stir this solution at 30°C to approx.
Hydrolysis was carried out with stirring for hours. Then, this was added with tetrabutyl titanate (T i (OnC4Hs)
4. Add a solution of 25.0 g (manufactured by Nippon Soda Co., Ltd.) dissolved in 0.24 L of isobutyl alcohol while stirring,
A mixed solution of tetraethyl silicate hydrolyzate and tetrabutyl titanate was prepared. Next, 0.39 L of methanol was added to a glass reaction vessel with an internal volume of 3 L equipped with a stirrer.
Then, 0.78 L of isobutyl alcohol was introduced, and 0.25 L of ammonia aqueous solution (concentration: 25 wt%) was added thereto to prepare an ammoniacal alcohol solution, and tetraethyl was added to this as an organosilicon compound solution for making silica seeds. A solution of 0.8 g of silicate dissolved in methanol 18n+1 was added, and 10 minutes after the addition was completed, the reaction solution became slightly milky white. Then, the above mixed solution was added over about 5 hours to form a reaction product. was precipitated. The temperature of the reaction vessel was maintained at 30° C. during the reaction. After the reaction was completed, stirring was continued for an additional 30 minutes, the solvent was removed from the milky white reaction solution using an evaporator, and the mixture was further dried under reduced pressure at 80°C to obtain a milky white powder. [0053] Next, this milky white powder was heated at 900°C for 1
After firing for a period of time, the mixture was dispersed in an agate mortar to obtain an inorganic oxide containing silica and titania as constituent components. As observed with a scanning electron microscope, the particle size of this inorganic oxide is 0.22 to 0.
．． The particle diameter was in the range of 42 μm, the average particle size was 0.29 μm, and the shape was pearl. (This powder is hereinafter referred to as Powder I) [0054] Production Example 2 In Production Example 1, 55% of the wax of tetrabutyl titanate was mixed.
An inorganic oxide was produced in exactly the same manner as in Production Example 1 except that the amount was 2 g. The particle size of the obtained inorganic oxide is 0. 10
~0.26μm, with an average particle size of 0619μm
m, and the shape was a perfect sphere. (This powder is hereinafter referred to as powder it) [0055] Production Example 3 5.0 g of 0.04% hydrochloric acid and tetraethyl silicate (S
1 (OC2H5) 4, manufactured by Nippon Colcourt Chemical Co., Ltd., product name: ethyl silicate 28), 300 g was dissolved in 0.44 L of methanol, and this solution was hydrolyzed while stirring at 30° C. for about 1 hour. Next, 1.0 ml of isobutyl alcohol was placed in a glass reaction vessel with an internal volume of 3 L equipped with a stirrer.
2 L of aqueous ammonia solution (
Concentration: 25 wt%) was added to prepare an ammoniacal alcohol solution, and to this was added a solution of 0.8 g of tetraethyl silicate dissolved in 18 ml of methanol as an organosilicon compound solution for making silica seeds, and the addition was completed 1.
After 0 minutes, when the reaction liquid became slightly milky, the above mixed solution was added over about 8 hours to precipitate the reaction product. During the reaction, the temperature of the reaction vessel was kept at 30°C.
It was kept at ℃. After the reaction was completed, stirring was continued for another 30 minutes, and the solvent was removed from the milky white reaction solution using an evaporator.
Further drying under reduced pressure at 80°C gave a milky white powder. [00561 Next, this milky white powder was heated at 900°C for 1
After firing for a period of time, the mixture was dispersed in an agate mortar to obtain an inorganic oxide containing silica as a constituent component. From observation using a scanning electron microscope, this inorganic oxide has a particle size of 0.46 to 0.95 μm.
The average particle diameter was 0.72 μm and the shape was a true sphere. (This powder is hereinafter referred to as powder III) [0057] Example I B is -GMA 60 parts by weight and TEGDMA 40
Parts by weight were mixed by stirring to obtain a uniform vinyl monomer liquid. Cover the container with aluminum foil to block light, then add CQo,
4 parts by weight and 4 parts by weight of DMPTo were added to the vinyl monomer solution and dissolved by stirring. [0058] On the other hand, 1100 parts by weight of powder and ultrafine particulate silica (manufactured by Tokuyama Soda Co., Ltd., QS-102, average particle size: 20n)
m) 10 parts by weight, 120 parts by weight of ethanol, and 5 parts by weight of γ-methacryloxypropyltrimethoxysilane were placed in a ball mill, and dispersed and mixed for 1 hour. The solvent was removed from this slurry liquid using an evaporator, and the slurry was further dried under reduced pressure at 80°C to obtain a surface-treated product. (Hereinafter, this surface-treated powder will be referred to as powder IV.) [0059] Also, quartz powder (manufactured by Ryumori Co., Ltd., VXS) was pulverized with a jet mill (manufactured by Seishin Enterprises, model FS-4) to obtain an average particle size. Finely ground quartz with a diameter of 2.7 μm was obtained. and,
This powder was surface-treated with γ-methacryloxypropyltrimethoxysilane. (Hereinafter, this surface-treated powder will be referred to as Powder V.) [00601] Next, 20 parts by weight of the vinyl monomer mixture, 24 parts by weight of Powder IV, and 56 parts by weight of Powder V were thoroughly kneaded in an agate mortar. , a paste was prepared. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When we measured the flow J of this paste immediately after its preparation and after leaving it at room temperature for one month, it was found to be OM in both cases.The compressive strength after curing was 3250 kg/cm2.The surface roughness was 0.11 μm. [00613 Example 2 B i s -GMA 75 parts by weight and TEGDMA2
5 parts by weight were stirred and mixed to obtain a uniform vinyl monomer liquid. Cover the container with aluminum foil to block light, and then
, and 4 parts by weight of DMPTo were added to the vinyl monomer liquid and dissolved by stirring. [0062] Next, 20 parts by weight of the vinyl monomer mixture, 24 parts by weight of Powder IV, and 56 parts by weight of Powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured immediately after preparation and after being left at room temperature for one month, it was found to be 0InI11 in both cases. The compressive strength after curing was 3170 kg/cm2. The surface roughness was 0.10 μm. [0063] Example 3 19 parts by weight of B i 5-MPEPP and NPCDMA
81 parts by weight were stirred and mixed to form a uniform vinyl monomer liquid. Cover the container with aluminum foil to block light, and then
4 parts by weight of DMPTo and 4 parts by weight of DMPTo were added to the vinyl monomer liquid and dissolved by stirring. [0064] Next, 20 parts by weight of the vinyl monomer mixture, 24 parts by weight of Powder IV, and 56 parts by weight of Powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. The flow j of this paste was measured immediately after preparation and after being left at room temperature for one month, and both were Omm. The compressive strength after curing was 3040 kg/cm2. Surface roughness is 0. It was 12 μm. [0065] Example 4 42 parts by weight of B i s -GMA, 28 parts by weight of TEGDMA and 30 parts by weight of A-TMM-3L were mixed by stirring,
A uniform vinyl monomer liquid was obtained. Cover the container with aluminum foil to block light, then add CQo, 4 parts by weight, and DMPTo.
, 4 parts by weight were added to the monomer solution and stirred to dissolve. [0066] Next, 20 parts of the above vinyl monomer mixture
24 parts by weight of powder IV and 56 parts by weight of powder V were sufficiently kneaded in an agate mortar to prepare a paste. After preparing the paste, defoaming was performed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured immediately after preparation and after being left at room temperature for one month, it was 0 mm in both cases. The E-line strength after curing was 3470 kg/cm''. The surface roughness was 0.10 μm. [0067] Example 5 60 parts by weight of B i s-GMA and 40 parts by weight of TEGDMA
Parts by weight were mixed by stirring to obtain a uniform vinyl monomer liquid. Cover the area around one vessel with aluminum foil to block light, then CQo,
4 parts by weight of DMPTo and 4 parts by weight of DMPTo were added to the vinyl monomer liquid and dissolved by stirring. [0068] On the other hand, 1100 parts by weight of powder, 10 parts by weight of ultrafine silica (manufactured by Tokuyama Soda Co., Ltd., QS-102), 120 parts by weight of ethanol, and 5 parts by weight of vinyltriethoxysilane were charged into a ball mill, and dispersed and mixed for 1 hour. do. The solvent was removed from this slurry liquid using an evaporator, and further 8
A surface-treated product was obtained by drying under reduced pressure at 0°C. (below,
This surface-treated powder is referred to as powder Vl. ) [00693
Next, 20 parts by weight of the vinyl monomer mixture and the powder VI
24 parts by weight and 56 parts by weight of powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured immediately after preparation and after being left at room temperature for one month, it was 0 mm in both cases. The compressive strength after curing was 3020 kg/cm''. The surface roughness was 0.1
It was 2 μm. [00701 Example 6 Vinyl monomer mixture 5 same as that used in Example 1
0 parts by weight, 15 parts by weight of powder FF, and 35 parts by weight of powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When we measured the "flow" of this paste, we found that it was 2
It was 1. The "flow" after being left at room temperature for one month was also in the second order. The compressive strength after curing was 3570 kg/cm2. The surface roughness was 0.09 μm. [00711 Example 7 15 parts by weight of a vinyl monomer mixture having the same composition as in Example 1, 25 parts by weight of Powder IV, and 60 parts by weight of Powder V were thoroughly kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. "Flow" of this paste immediately after preparation and after being left at room temperature for one month
When measured, they were all 0 nus. The compressive strength after curing was 3650 kg/cn2. The surface roughness was 0.11 μm. [0072] Example 8 B i s -GMA60 phoenix part and TEGDMA40
Parts by weight were mixed with stirring to obtain a homogeneous monomer solution. Cover the container with aluminum foil to block light, then add CQo,
4 parts by weight and 4 parts by weight of DMPTo were added to the vinyl monomer solution and dissolved by stirring. [0073] On the other hand, 100 parts by weight of powder II and 15 parts by weight of ultrafine particulate silica (manufactured by Tokuyama Soda Co., Ltd., QS-102),
120 parts by weight of ethanol and 8 parts by weight of γ-methacryloxypropyltrimethoxysilane were charged into a ball mill.
Mix over time. The solvent was removed from this slurry liquid using an evaporator, and the slurry was further dried under reduced pressure at 80°C to obtain a surface-treated product. (Hereinafter, this surface-treated powder will be referred to as powder V.
It is called II. ) [0074] Next, 20 parts by weight of the above vinyl monomer mixture, 60 parts by weight of powder VII, and polydiethylene glycol bisallyl carbonate (Japanese Patent Application Laid-Open No. 104914-1989)
20 parts by weight (as disclosed in 1999, average particle size: 40 μm) were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured immediately after preparation and after being left at room temperature for one month, it was 0 mm in both cases. The compressive strength after curing was 2780 kg/cm2. Surface roughness is 0
．． It was 07 μm. [0075] Example 9 B i s -GMA 60 parts by weight and TEGDMA 40
Parts by weight were mixed by stirring to obtain a uniform vinyl monomer liquid. Cover the container with aluminum foil to block light, then add CQo,
4 parts by weight and 4 parts by weight of DMPTo were added to the vinyl monomer solution and dissolved by stirring. [0076] Meanwhile, 111,100 parts by weight of powder, 5 parts by weight of ultrafine silica (manufactured by Tokuyama Soda Co., Ltd., QS-102), 120 parts by weight of ethanol, and 4 parts by weight of γ-methacryloxypropyltrimethoxysilane were charged into a ball mill. Disperse and mix for 1 hour. The solvent was removed from this slurry liquid using an evaporator, and the slurry was further dried under reduced pressure at 80°C to obtain a surface-treated product. (Hereinafter, this surface-treated powder will be referred to as Powder VI
It is called II. ) [0077] Next, 20 parts by weight of the vinyl monomer mixture, 24 parts by weight of powder Vllll, and 56 parts by weight of powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured immediately after preparation and after being left at room temperature for one month, it was found to be OM in both cases. The compressive strength after curing was 3060 kg/cm2. The surface roughness was 0.12 μm. [0078] Example 10 B i s -GMA 60 parts by weight and TEGDMA 40
Parts by weight were mixed by stirring to obtain a uniform vinyl monomer liquid. Cover the container with aluminum foil to block light, then add CQo,
4 parts by weight of DMPTo and 4 parts by weight of DMPTo were added to the vinyl monomer solution and dissolved by stirring. [0079] On the other hand, 1100 parts by weight of powder and ultrafine particulate silica (manufactured by Nippon Aerosil Co., Ltd., 0X-50, average particle size: 4
0 nm), 120 parts by weight of ethanol, and 5 parts by weight of γ-methacryloxypropyltrimethoxysilane were placed in a ball mill, and the mixture was dispersed and mixed for 1 hour. The solvent was removed from this slurry liquid using an evaporator, and the slurry was further dried under reduced pressure at 80°C to obtain a surface-treated product. (Hereinafter, this surface-treated powder will be referred to as powder IX.) vinyl monomer mixture (B i 5-MPEPP 19% by weight)
, 30 parts by weight of NPGDMA (81% by weight) and 0.125 parts by weight of azobisisobutyronitrile were mixed and sufficiently kneaded to obtain a paste. And 5kg/cm2
Polymerization was carried out under nitrogen pressure at a molding temperature of 120° C. for 1 hour on the machine to obtain a polymer. This polymer was crushed in a mortar to a size of 5 mm or less, and then crushed in a colander for 1 hour. After pulverization, a powder (hereinafter referred to as powder X) that passed through a 250-mesh sieve was obtained. [00811] Next, 20 parts by weight of the vinyl monomer mixture, 24 parts by weight of powder IX, and 56 parts by weight of powder X were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured immediately after preparation and after being left at room temperature for one month, it was 0 mm in both cases. The compressive strength after curing was 3510 kg/cm2. The surface roughness was 0.03 μm. [0082] Comparative Example 1 1100 parts by weight of powder, 100 parts by weight of ethanol, and 2 parts by weight of γ-methacryloxypropyltrimethoxysilane were placed in a ball mill and dispersed and mixed for 1 hour. Additionally, 10 parts by weight of ultrafine silica (manufactured by Tokuyama Soda Co., Ltd., QS-102, average particle size: 20 nm), 100 parts by weight of ethanol,
3 parts by weight of γ-methacryloxypropyltrimethoxysilane was placed in a ball mill and mixed for 1 hour. Remove the solvent from each of these slurry liquids using an evaporator,
Further, surface-treated products were obtained by drying under reduced pressure at 80°C. (Hereinafter, the former surface-treated powder will be referred to as powder A, and the latter surface-treated powder will be referred to as powder B.) [00831 Next, 20 parts by weight of the same vinyl monomer mixture as used in Example 1 was added. 21.8 parts by weight of Powder A, 2.2 parts by weight of Powder B, and 56 parts by weight of Powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured, it was 9 mm. [0084] Comparative Example 2 Vinyl monomer mixture 2 same as that used in Example 2
0 parts by weight, 21.8 parts by weight of powder A, 2.2 parts by weight of powder B, and 56 parts by weight of powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. The “flow” of this paste
When measured, it was 7 mm. [0085] Comparative Example 3 Vinyl monomer mixture 2 same as that used in Example 3
0 parts by weight, 21.8 parts by weight of powder A, 2.2 parts by weight of powder B, and 56 parts by weight of powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. The “flow” of this paste
When measured, it was 11 mm. [0086] Comparative Example 4 Vinyl monomer mixture 2 same as that used in Example 4
Powder A, 21.8 parts by weight of Powder A, 2.2 parts by weight of Powder B, and 56 parts by weight of Powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. The “flow” of this paste
When measured, it was 14 mm. [0087] Comparative Example 5 Powder I and ultrafine particulate silica (manufactured by Tokuyama Soda Co., Ltd., QS- 102) was subjected to surface treatment to obtain Powder C and Powder I, respectively. [00881 Next, 20 parts by weight of the same vinyl monomer mixture as used in Example 1, 21.8 parts by weight of Powder C, 2.2 parts by weight of Powder D, and 56 parts by weight of Powder V were sufficiently mixed in an agate mortar. The mixture was kneaded to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. The "flow" of this paste was measured and was found to be 6 degrees. [0089] Comparative Example 6 Same vinyl monomer mixture solution 5 as used in Example 1
0 parts by weight, 45.5 parts by weight of powder A, and 4.5 parts by weight of powder B were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When we measured the "flow" of this paste, we found that
It was 35 mm. [00903 Comparative Example 7 Vinyl monomer mixture 1 same as that used in Example 1
5 parts by weight of Powder A, 22.7 parts by weight of Powder A, 2.3 parts by weight of Powder B, and 60 parts by weight of Powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. The “flow” of this paste
When measured, it was 15 ■. [0091] Comparative Example 8 11,100 parts by weight of powder, 100 parts by weight of ethanol, γ-
5 parts by weight of methacryloxypropyltrimethoxysilane was placed in a ball mill and mixed for 1 hour. The solvent was removed from this slurry liquid using an evaporator, and the temperature was further increased to 80°C.
A surface-treated product was obtained by drying under reduced pressure. (Hereinafter, this surface-treated powder will be referred to as powder E.) [00921 Next, 20 parts by weight of the same vinyl monomer mixture used in Example 1 and 54.5 parts by weight of powder E,
A paste was prepared by thoroughly kneading 5.5 parts by weight of Powder B and 20 parts by weight of polydiethylene glycol bisallyl carbonate (disclosed in JP-A-56-104914, average particle size 40 μm) in an agate mortar. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured, it was 12 mm. [0093] Comparative Example 9 1100 parts by weight of powder, 100 parts by weight of ethanol, γ
21 parts by weight of methacryloxypropyltrimethoxysila was charged into a ball mill and dispersed and mixed for 1 hour. The solvent was removed from this slurry liquid using an evaporator, and the temperature was further increased to 80°C.
A surface-treated product was obtained by drying under reduced pressure. (Hereinafter, this surface-treated powder will be referred to as powder F.) [00941 Next, 20 parts by weight of the same vinyl monomer mixture as used in Example 1 and 21.8 parts by weight of powder F,
2.2 parts by weight of Powder B and 5656 parts by weight of Powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. The "flow" of this paste was measured and found to be 11 mm. [0095] Comparative Example 10 Ultrafine particulate silica (manufactured by Nippon Aerosil Co., Ltd., 0X-50,
10 parts by weight (average particle size: 40 millimicrons), 100 parts by weight of ethanol, and 3 parts by weight of γ-methacryloxypropyltrimethoxysilane were placed in a ball mill, and dispersed and mixed for 1 hour. The solvent was removed from this slurry liquid using an evaporator, and the slurry was further dried under reduced pressure at 80°C to obtain a surface-treated product. (Hereinafter, this surface-treated powder will be referred to as powder G.) [00961 Next, 20 parts by weight of the same vinyl monomer mixture used in Example 1, 21.8 parts by weight of powder A, and powder G2 .2 parts by weight and 56 parts by weight of powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured, it was 12 mm. [0097] Comparative Example 11 Quartz powder (manufactured by Tatsumori Co., Ltd., VXS) was pulverized with a jet mill (manufactured by Seishin Enterprises, model FS-4) to obtain an average particle size of 2°7.
Finely ground quartz of μm size was obtained. Then, 100 parts by weight of this powder and ultrafine particulate silica (manufactured by Tokuyama Soda Co., Ltd., QS-102,
10 parts by weight (average particle size: 20 mm), 120 parts by weight of ethanol, and 4 parts by weight of γ-methacryloxypropyltrimethoxysilane were dispersed and mixed using a homogenizer. Remove the solvent from this slurry liquid using an evaporator,
Further, a surface-treated product was obtained by drying under reduced pressure at 80°C. (Hereinafter, this surface-treated powder will be referred to as powder H.) [0
Next, 20 parts by weight of the same vinyl monomer mixture used in Example 1 and 80 parts by weight of powder H were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured, it was Omm. The surface roughness was 0.14 μm. [0099] Comparative Example 12 100 parts by weight of the finely ground quartz used in Comparative Example 11, 120 parts by weight of ethanol, and 1 part by weight of γ-methacryloxypropyltrimethoxysilane are dispersed and mixed using a homogenizer. The solvent was removed from this slurry liquid using an evaporator, and the slurry was further dried under reduced pressure at 80°C to obtain a surface-treated product. (Hereinafter, this surface-treated powder will be referred to as powder J.) [
01003 Next, 20 parts by weight of the same vinyl monomer mixture used in Example 1, 72.7 parts by weight of powder J, and 87.3 parts by weight of powder were thoroughly kneaded in an agate mortar to prepare a paste. did. After the paste was prepared, it was defoamed under reduced pressure to remove air bubbles from the paste. When the "flow" of this paste was measured, it was OM. Surface roughness is 0.17μm
Met. [0101] Comparative Example 13 20 parts by weight of a vinyl monomer mixture having the same composition as in Example 1, 21.8 parts by weight of powder A, and 2.2 parts of hydrophilic ultrafine particulate silica (manufactured by Tokuyama Soda Co., Ltd., QS-102). Parts by weight and 56 parts by weight of powder V were sufficiently kneaded in an agate mortar to prepare a paste. After the paste was prepared, air bubbles were removed from the paste by defoaming under reduced pressure. When the "flow" of this paste was measured, it was Omm. Furthermore, the paste is heated to 1 at room temperature.
After leaving it for several months, the "flow" was measured in the same way and found to be 6 mm. [0102]

[Effects of the Invention] The dental composite material prepared by the production method of the present invention inherently has poor shapeability, which is a major drawback when the main component is a submicron spherical inorganic filler. It has the great advantage of being able to be improved without losing its features. That is, it has the excellent advantage that the shapeability can be greatly improved without losing the smoothness of the polished surface, which is its major feature. The feature that the polished surface is smooth is an important property from the aesthetic point of view for dental composite materials, especially composite resins for dental restorations. It is also advantageous in terms of wear resistance. Moreover, according to the present invention, there is a great advantage that the shapeability can be improved with almost no effect on mechanical strength. Furthermore, the present invention has the great advantage that by adjusting the content of the ultrafine particulate inorganic filler, it is possible to impart optimal fluidity to the dental composite material according to each purpose. This point is the greatest advantage for dental materials for which ease of use is most important. As described above, the dental composite material of the present invention has many advantages, and can be applied to resins for dental crowns in addition to composite resins for restorations in the dental field.

Claims (1)

[Claims] Claim 1: (a) Polymerizable vinyl monomer 10-6
0 parts by weight, (b) Spherical inorganic filler 10 with an average particle size of 0.1 to 1 μm
Powdered filler 90 containing 0.01% by weight or more of ultrafine particulate inorganic filler with an average particle size of 10 to 50 nm.
~ 40 parts by weight, and (c) 0.001 to 5% by weight of a polymerization initiator based on the total material. The above-mentioned manufacturing method is characterized in that the surface is simultaneously treated with a compound that reacts with hydroxyl groups.