Composite material with low porosity and method for producing the same

Abstract

The present invention relates to a method for producing a low-porosity composite material by applying a vacuum to a mixing vessel before the actual mixing process. The composite material comprises a monomer mixture and a glass filler or a blend of glass fillers. The monomer mixture comprises at least one polymerizable monomer, a polymerization initiator, and a polymerization stabilizer. Optionally, the composite material may comprise at least one pigment. The porosity of the composite material is determined and compared to the porosity of a composite material produced by a method in which no vacuum was applied before all mixing steps. Preferred mixing vessels for the method of the present invention are planetary mixers or centrifugal mixers. The composite material is used in the dental industry.

Description

Background Art

[0001] The present invention relates to a dental composite material used in the dental field for filling restoration, prosthetic restoration, temporary sealing, temporary adhesion, prosthetic fabrication, adhesion, bonding, and cryptofisher sealing. More specifically, the present invention relates to a paste-like composite material prepared by mixing a filler and a polymerizable monomer, which is used in composite resin, temporary filling material, resin cement, adhesive, or fisher sealant.

[0002] In the dental field, a composite material is prepared by a method including kneading and mixing a filler and at least one polymerizable monomer in the form of a paste. The paste-like composite material (composite material in the form of a paste) is provided to dentists and dental technicians, who are users of the composite material, in a packaging container filled with the composite material. The composite material may be blended with an adhesive monomer, pigment, etc. However, according to the purpose of use, the composite material is usually prepared in the form of a paste by mixing an appropriate amount of a filler and at least one polymerizable monomer, and then filled into a packaging container.

[0003] Air is contained in the material during the mixing and kneading steps of paste production, resulting in porosity. Porosity and the inclusion of air (air bubbles) have an adverse effect on the mechanical and aesthetic properties of the dental composite material.

[0004] EP2985016 and US10,780,027 of Shofu, Inc. disclose a paste-like composite material containing a silanized filler and a mixed polymerizable monomer having stable paste properties, and a method for manufacturing the same. Among the methods, the mixing and kneading steps are carried out at normal pressure, and then a vacuum mixing step is carried out to reduce the porosity of the paste by including air. In the vacuum mixing step, the materials are first mixed and then a vacuum is applied. In other words, the paste is degassed after mixing. The presence of air bubbles in the composite material was tested by an air bubble mixing test. The result was "B". It is an object of the present invention to provide a composite material having a lower level of porosity when compared with the prior art. Simple Summary

[0005] Regarding the present invention, the composite material is a paste-like composite material.

[0006] Regarding the present invention, the composite material is either a shade-free composite material or a shaded composite material.

[0007] Regarding the present invention, the shaded composite material is a composite material containing at least one pigment.

[0008] Regarding the present invention, rpm is the unit of impeller speed (revolutions per minute).

[0009] Regarding the present invention, the speed or mixing speed is the impeller speed.

[0010] Regarding the present invention, Ormosil-Resin is a mixture of ethoxylated bisphenol dimethacrylate, dodecanediol dimethacrylate, and Ormocer®, and is a product well-known in the dental field.

[0011] Dentists and dental technicians require composite materials with low porosity. Low porosity results in more uniform polymerization and improved quality of the final product. Low porosity also has extremely great aesthetic and visual advantages, limiting the need to polish the composite material. In addition to this, low porosity reduces the possibility of cracks and weakness in the composite material and increases the clinical use time. Furthermore, low porosity increases the thermal stability of the composite material.

[0012] It is an object of the present invention to provide a composite material having a lower level of porosity and a method for manufacturing the same.

[0013] The embodiments described herein can prepare a composite material with low porosity by performing the mixing step under vacuum to reduce the inclusion of air. The vacuum is applied before the actual mixing of one component begins.

[0014] The objects, features, and advantages of the present invention will also become apparent by reading the following description in conjunction with the drawings.

Brief Description of the Drawings

[0015]

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[0016] Described herein is a composite material comprising a glass filler or blend of glass fillers, a monomer mixture, and optionally at least one pigment, wherein the monomer mixture comprises one or more polymerizable monomers, a polymerization initiator, and a polymerization stabilizer, and the composite material is produced by the following method: A method of mixing a glass filler or blend of glass fillers and a monomer mixture, and optionally at least one pigment, in a mixing vessel in more than one step under vacuum, wherein a vacuum is applied to the mixing vessel before each mixing step is initiated, and the vacuum is preferably 45 - 800 mbar.

[0017] The weight ratio of the monomer mixture to the glass filler or blend of glass fillers is preferably from 2 - 4 to 5 - 7, more preferably from 3 - 4 to 5.5 - 6.5, and most preferably from 3.5 to 5.9.

[0018] More specifically, the present invention is a method for manufacturing a composite material, the steps of which are: a. Charging a monomer mixture into a mixing vessel; b. Charging a portion of the glass filler or blend of glass fillers into the mixing vessel to form a mixture, placing the mixture under vacuum, and mixing the mixture. c. Introduce a portion of the glass filler or blend of glass fillers into a mixing vessel to produce a mixture, place the mixture under vacuum, and mix the mixture. d. Place the mixture under vacuum and mix it to produce a paste. e. Adjust the paste. f. Place the paste under vacuum and mix it to produce a composite material, and optionally g. Add at least one pigment, and optionally also a glass filler or blend of glass fillers and / or a monomer mixture to the composite material to produce a mixture, place the mixture under vacuum, and mix the mixture to produce a composite material. A method including these steps is described.

[0019] In another aspect of the present invention, step g. of the method described above is as follows: Add at least one pigment, and a glass filler or blend of glass fillers and a monomer mixture to the composite material to produce a mixture, place the mixture under vacuum, and mix the mixture to produce a composite material.

[0020] In another aspect of the present invention, a method for producing a composite material as described above, The vacuum in steps b., c., and d. is 650 - 800 mbar, The mixing in step b. is carried out at a temperature of 23 - 27°C at a speed of 8 - 12 rpm for 2 - 5 minutes, and then at a speed of 13 - 16 rpm for 8 - 12 minutes, and thus the step can be carried out 1 - 5 times. The mixing in step c. is carried out at a temperature of 23 - 27°C at a speed of 12 - 16 rpm for 22 - 27 minutes, and thus the step can be carried out 1 - 4 times. The mixing in step d. is carried out at a temperature of 23 - 27°C at a speed of 10 - 14 rpm for 110 - 130 minutes, and thus this step can be carried out 1 - 3 times. The adjustment in step e. is carried out at a temperature of 45 - 55°C for 36 - 50 hours under anaerobic conditions. The vacuum in step f. is a vacuum of 210 to 230 mbar, and the mixing in step f. is carried out at a temperature of 46 to 48 °C at a speed of 6 to 10 rpm for 18 to 22 minutes. The mixing in step g. is carried out at a temperature of 23 to 27 °C at a speed of 5 to 15 rpm in at least three steps, whereby each of the steps is continued for 5 to 45 minutes, and a vacuum of 45 to 800 mbar is set before each mixing step starts.

[0021] In yet another aspect of the present invention, there is a method for manufacturing a composite material, the steps: a. A step of introducing a monomer mixture into a mixing container, b. A step of introducing a first portion of a glass filler or a blend of glass fillers into the mixing container to form a mixture, placing the mixture under a vacuum of 700 mbar, and mixing it at a temperature of 25 °C at a speed of 10 rpm for 3 minutes, and then at a speed of 15 rpm for 10 minutes. c. A step of introducing a second portion of a glass filler or a blend of glass fillers into the mixing container to form a mixture, placing the mixture under a vacuum of 700 mbar, and mixing it at a temperature of 25 °C at a speed of 10 rpm for 3 minutes, and then at a speed of 15 rpm for 10 minutes. d. A step of introducing a third portion of a glass filler or a blend of glass fillers into the mixing container to form a mixture, placing the mixture under a vacuum of 700 mbar, and mixing it at a temperature of 25 °C at a speed of 10 rpm for 3 minutes, and then at a speed of 15 rpm for 10 minutes. e. A step of introducing a fourth portion of a glass filler or a blend of glass fillers into the mixing container to form a mixture, placing the mixture under a vacuum of 700 mbar, and mixing it at a temperature of 25 °C at a speed of 15 rpm for 25 minutes. f. A step of introducing a fifth portion of a glass filler or a blend of glass fillers into the mixing container to form a mixture, placing the mixture under a vacuum of 700 mbar, and mixing it at a temperature of 25 °C at a speed of 15 rpm for 25 minutes. g. Add a sixth portion of the glass filler or blend of glass fillers to the mixing vessel to produce a mixture, place the mixture under a vacuum of 700 mbar, and mix it at a temperature of 25 °C at a speed of 15 rpm for 25 minutes to produce a mixture. h. Place the mixture under a vacuum of 700 mbar and mix it at a temperature of 25 °C at a speed of 12 rpm for 120 minutes to produce a mixture. i. Place the mixture under a vacuum of 700 mbar and mix it at a temperature of 25 °C at a speed of 12 rpm for 120 minutes to produce a paste. j. Adjust the paste at a temperature of 50 °C for 36 - 48 hours under anaerobic conditions. k. Place the paste in the mixing vessel under a vacuum of 220 mbar and mix it at a temperature of 48 °C at a speed of 8 rpm for 20 minutes to produce a composite material, and optionally l. Add at least one pigment, and optionally a glass filler or blend of glass fillers and / or a monomer mixture to the composite material to produce a mixture, place the mixture under a vacuum of 700 mbar, and mix it at a temperature of 25 °C at a speed of 15 rpm for 30 minutes. m. Place the mixture under a vacuum of 700 mbar and mix it at a temperature of 25 °C at a speed of 15 rpm for 45 minutes. n. Place the mixture under a vacuum of 700 mbar and mix it at a temperature of 25 °C at a speed of 15 rpm for 45 minutes. o. Place the mixture under a vacuum of 700 mbar and mix it at a temperature of 25 °C at a speed of 15 rpm for 45 minutes. p. Place the mixture under a vacuum of 50 mbar and mix it at a temperature of 25 °C at a speed of 8 rpm for 15 minutes. q. Place the mixture under a vacuum of 50 mbar and mix it at a temperature of 25 °C at a speed of 5 rpm for 5 minutes to produce a composite material. There is a method including the above.

[0022] In another aspect of the present invention, step l. of the above-described method is as follows: Adding at least one pigment, as well as a glass filler or blend of glass fillers and a monomer mixture to a composite material to produce a mixture, placing the mixture under a vacuum of 700 mbar, and mixing it at a temperature of 25 °C at a speed of 15 rpm for 30 minutes.

[0023] Preferred mixing vessels for the method described above are planetary mixers or centrifugal mixers.

[0024] In another aspect of the present invention, the term "glass filler or blend of glass fillers" may be replaced by "blend of glass fillers".

[0025] In yet another aspect of the present invention, the method described above includes adding YbF3 together with the monomer mixture and / or the glass filler or blend of glass fillers.

[0026] The produced composite material was subjected to a porosity test, and the porosity distribution in the composite material was determined.

[0027] One or more polymerizable monomers used in this embodiment are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, glycidyl acrylate, glycidyl methacrylate, diglycidyl methacrylate of bisphenol A, glycerol mono- and di-acrylates, glycerol mono- and di-methacrylates, ethylene glycol diacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate (the number of repeating ethylene oxide units varies from 2 to 30), polyethylene glycol dimethacrylate (the number of repeating ethylene oxide units varies from 2 to 30, especially triethylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, mono-, di-, tri-, and tetra-acrylates and methacrylates of pentaerythritol and dipentaerythritol, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, di-2-methacryloyloxyethyl hexamethylene dicarbamate, di-2-methacryloyloxyethyl trimethylhexane ethylene dicarbamate, di-2-methacryloyloxyethyl dimethylbenzene dicarbamate, methylene-bis-2-methacryloxyethyl-4-cyclohexylcarbamate, di-2-methacryloxyethyl-dimethylcyclohexane dicarbamate, methylene-bis-2-methacryloxyethyl-4-cyclohexylcarbamate, di-1-methyl-2-methacryloxyethyl-trimethylhexamethylene dicarbamate,Di-1-methyl-2-methacryloxyethyl-dimethylbenzene dicarbamate, di-1-methyl-2-methacryloxyethyl-dimethylcyclohexane dicarbamate, methylene-bis-1-methyl-2-methacryloxyethyl-4-cyclohexylcarbamate, di-1-chloromethyl-2-methacryloxyethyl-hexamethylene dicarbamate, di-1-chloromethyl-2-methacryloxyethyl-trimethylhexamethylene dicarbamate, di-1-chloromethyl-2-methacryloxyethyl-dimethylbenzene dicarbamate, di-1-chloromethyl-2-methacryloxyethyl-dimethylcyclohexane dicarbamate, methylene-bis-2-methacryloxyethyl-4-cyclohexylcarbamate, di-1-methyl-2-methacryloxyethyl-hexamethylene dicarbamate, di-1-methyl-2-methacryloxyethyl-trimethylhexamethylene dicarbamate, di-1-methyl-2-methacryloxyethyl-dimethylbenzene dicarbamate, di-1-methyl-2-methacryloxyethyl-dimethylcyclohexane dicarbamate, methylene-bis-1-methyl-2-methacryloxyethyl-4-cyclohexylcarbamate, di-1-chloromethyl-2-methacryloxyethyl-hexamethylene dicarbamate, di-1-chloromethyl-2-methacryloxyethyl-trimethylhexamethylene dicarbamate, di-1-chloromethyl-2-methacryloxyethyl-dimethylbenzene dicarbamate, di-1-chloromethyl-2-methacryloxyethyl-dimethylcyclohexane dicarbamate, methylene-bis-1-chloromethyl-2-methacryloxyethyl 4-cyclohexylcarbamate, 2,2'-bis(4-methacryloxyphenyl)propane, 2,2'-bis(4-acryloxyphenyl)propane, 2,2'-bis[4(2-hydroxy-3-methacryloxy-phenyl)]propane, 2,2'-bis[4(2-hydroxy-3-acryloxy-phenyl)propane, 2,2'-bis(4-methacryloxyethoxyphenyl)propane, 2,2'-bis(4-acryloxyethoxyphenyl)propane, 2,2'-bis(4-methacryloxypropoxyphenyl)propane, 2,2'-bis(4-acryloxypropoxyphenyl)propaneIt is selected from the group containing, but not limited to, acrylates and methacrylates including 2,2'-bis(4-methacryloxydiethoxyphenyl)propane, 2,2'-bis(4-acryloxydiethoxyphenyl)propane, 2,2'-bis[3(4-phenoxy)-2-hydroxypropane-1-methacrylate]propane, and 2,2'-bis[3(4-phenoxy)-2-hydroxypropane-1-acrylate]propane.,

[0028] In a preferred embodiment of the present invention, one or more polymerizable monomers are selected from the group containing ethoxylated bisphenol dimethacrylate, triethylene glycol dimethacrylate, urethane dimethacrylate, and Ormosil-Resin.

[0029] The polymerization stabilizer used in the embodiments of the present invention is selected from the group containing butylated hydroxytoluene, hydroquinone monomethyl ether, tert.-butylhydroquinone, tert.-butylhydroxyanisole, 2,6-di-tert.-butyl-p-cresol, tetramethylpiperidine N-oxyl radical, and galvanoxyl radical.

[0030] In a preferred embodiment of the present invention, the polymerization stabilizer is butylated hydroxytoluene.

[0031] The polymerization initiator used in the embodiments of the present invention is a photoinitiator that can promote the polymerization of polymerizable groups when exposed to light of appropriate wavelength and intensity. The photoinitiator is preferably sufficiently storage-stable and free of undesired coloring in order to enable storage and use under typical dental conditions. Photoinitiators for visible light are preferred. Initiators induced by appropriate visible light and initiators induced by ultraviolet light include alpha-diketones (such as camphorquinone) which may or may not have a further hydrogen donor (such as sodium benzenesulfinate, amines, and amino alcohols). The photoinitiator is present in an amount sufficient to provide photopolymerization at a desired rate.

[0032] Alternatively, a redox system can be used as a polymerization initiator. The redox type polymerization initiator system of the present invention includes, but is not limited to, a system of an organic peroxide / amine compound or an organic peroxide / amine compound / sulfinate, or an inorganic peroxide / amine compound / sulfinate. The organic peroxide may include, but is not limited to, benzoyl peroxide, lauroyl peroxide, and cumene hydroperoxide. The inorganic peroxide may include, but is not limited to, potassium peroxodisulfate and sodium peroxodisulfate. The amine may include, but is not limited to, N-methylaniline, N,N-dimethylaniline, t-butyl-N,N-dimethylaniline, and p-N,N-dimethyltoluidine. The sulfinate may include, but is not limited to, sodium p-toluenesulfinate, lithium p-toluenesulfinate, sodium benzenesulfinate, and lithium benzenesulfinate.

[0033] In a preferred embodiment of the present invention, the polymerization initiator includes camphorquinone and ethyl 4-(dimethylamino)benzoate.

[0034] The glass filler of the present invention may be a silanized glass filler.

[0035] The surface of the glass filler of the present invention may be modified before the mixing step. Accordingly, the surface modifier contains a modifying compound that can react with the surface atoms of the filler, thereby forming a covalent bond between the surface atoms of the filler and the modifying compound. Further, the modifying compound may contain one or more polymerizable double bonds that are reactive in a crosslinking reaction after the filler is modified. The modifier may contain one or more modifying compounds. Preferably, the modifying compound may be a compound of one of the following formulas (I), (II), and (III), or a hydrolysis product thereof, providing a polymerizable ligand capable of crosslinking X r R 3-r SiL(I) X r R 2-rSiL’L’’(II) X r SiL’L’’L’’’(III) (wherein X represents a hydrolyzable group, R represents an alkyl, cycloalkyl, cycloalkylalkyl, aralkyl, or aryl group, L, L’, L’’, and L’’’ may be the same or different and each independently represents an organic group containing one or more polymerizable double bonds, r is an integer from 1 to 3, such that the sum of X, R, L, L’, L’’, and L’’’ is 4 for each of the formulas (I), (II), and (III)).

[0036] Preferably, X is a hydrogen atom or OR 1 and R 1 is an alkyl, cycloalkyl, cycloalkylalkyl, aralkyl, or aryl group. More preferably, R or R 1 is independently an alkyl group.

[0037] To impart crosslinking performance to the organofunctional silicon compound, L, L’, L’’, and L’’’ contain one or more polymerizable double bonds that can participate in the crosslinking reaction. In a preferred embodiment, L, L’, L’’, and L’’’ may be selected from the group consisting of allyl, (meth)acrylic ester groups, and (meth)acrylamide groups.

[0038] The alkyl group may be a linear or branched C1-C16 alkyl group, typically a C1-C8 alkyl group. Examples of C1-C6 alkyl groups include linear or branched alkyl groups having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, and n-hexyl. The cycloalkyl group may be a C3-C16 cycloalkyl group. Examples of cycloalkyl groups include those having 3 to 14 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. The cycloalkylalkyl group may include those having 4 to 22 carbon atoms. Examples of cycloalkylalkyl groups can include combinations of linear or branched alkyl groups having 1 to 6 carbon atoms and cycloalkyl groups having 3 to 14 carbon atoms. Examples of cycloalkylalkyl groups can include, for example, methylcyclopropyl, methylcyclobutyl, methylcyclopentyl, methylcyclohexyl, ethylcyclopropyl, ethylcyclobutyl, ethylcyclopentyl, ethylcyclohexyl, propylcyclopropyl, propylcyclobutyl, propylcyclopentyl, propylcyclohexyl. The aralkyl group may be a C7-C26 aralkyl group, typically a combination of a linear or branched alkyl group having 1 to 6 carbon atoms and an aryl group having 6 to 10 carbon atoms. Specific examples of aralkyl groups are the benzyl group or the phenylethyl group. The aryl group can include an aryl group having 6 to 10 carbon atoms. Examples of aryl groups are phenyl or naphthyl. The C1-C6 alkyl group and the C3-C14 cycloalkyl group may be optionally substituted by one or more members of a group selected from a C1-C4 alkyl group, a C1-C4 alkoxy group, a phenyl group, and a hydroxy group. Examples of C1-C4 alkyl groups include linear or branched alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl.Examples of C1-4 alkoxy groups can include linear or branched alkoxy groups having 1 to 4 carbon atoms, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, and tert-butoxy.

[0039] The aryl group may contain 1 to 3 substituents. Examples of such substituents can include a halogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a C1-4 alkylthio group, a C1-4 alkylsulfonyl group, a carboxyl group, a C2-5 alkoxycarbonyl group, and a C1-4 alkylamino group. Here, specific examples of the halogen atom can be fluorine, chlorine, bromine, and iodine. The C1-4 alkyl group can be, for example, methyl, ethyl, n-propyl, isopropyl, and n-butyl. Specific examples of the C1-4 alkoxy group can be, for example, methoxy, ethoxy, and propoxy. Specific examples of the C1-4 alkylthio group can be, for example, methylthio, ethylthio, and propylthio. Specific examples of the C1-4 alkylsulfonyl group can be, for example, methylsulfonyl, ethylsulfonyl, and propylsulfonyl. Specific examples of the C2-5 alkoxycarbonyl group can be those having an alkoxy group containing 1 to 4 carbon atoms each, such as methoxycarbonyl, ethoxycarbonyl, and propoxycarbonyl. Specific examples of the C1-8 alkylamino group can be those having one or two amino groups each containing 1 to 4 carbon atoms, such as methylamino, dimethylamino, ethylamino, and propylamino. The alkyl moiety in these substituents may be linear, branched, or cyclic.

[0040] It is an object of the present invention to provide a composite material produced by the method described above.

[0041] A composite material comprising one or more polymerizable monomers, a polymerization initiator, a polymerization stabilizer, and a glass filler or a blend of glass fillers, wherein the composite material has a number of bubbles of size L less than 20, a number of bubbles of size M less than 100, and a number of bubbles of size M+L less than 120, determined by the method defined in the examples. It is an object of the present invention to provide such a composite material.

[0042] A composite material comprising ethoxylated bisphenol dimethacrylate, triethylene glycol dimethacrylate, urethane dimethacrylate, and Ormosil-Resin, camphorquinone and ethyl 4-(dimethylamino)benzoate, butylated hydroxytoluene, YbF3, a blend of glass fillers, and at least one pigment, wherein the composite material has a number of bubbles of size L of 12, a number of bubbles of size M of 85, and a number of bubbles of size M+L of 97, determined by the method defined in the examples. It is also an object of the present invention to provide such a composite material. The composite material is used in the dental industry, and more specifically, it is used to manufacture composite resins, temporary cements, resin cements, adhesives, or fissure sealants.

[0043] [Example] Example 1 describes a method for manufacturing a composite material in which a vacuum is applied to the mixing container before each mixing step is started.

[0044] Example 2 describes a method for manufacturing a composite material in which most of the mixing steps are carried out at atmospheric pressure.

[0045] Example 3 describes a method (laboratory scale) for manufacturing a composite material in which a vacuum is applied to the mixing container before each mixing step is started.

[0046] Example 4 describes a method (laboratory scale) for manufacturing a composite material in which most of the mixing steps are carried out at atmospheric pressure.

[0047] Example 5 describes a method (laboratory scale) for manufacturing a composite material in which a vacuum is applied to the mixing vessel before each mixing step is started.

[0048] Example 6 describes a method (laboratory scale) for manufacturing a composite material in which most of the mixing steps are carried out at atmospheric pressure.

[0049] Example 7 describes a method for determining the porosity of a composite material and the results thereof.

[0050] Example 1 At 25 °C, in a 30 l container of a planetary mixer, 5.9 kg of a filler blend containing 55 wt% silanized glass filler and 45 wt% SphereTEC filler was added to 3.5 kg of a monomer mixture containing ethoxylated bisphenol dimethacrylate, triethylene glycol dimethacrylate, urethane dimethacrylate, and Ormosil-Resin, as well as camphorquinone / ethyl 4-(dimethylamino)benzoate, butylated hydroxytoluene, 0.6 kg of YbF3.

[0051] In the first step, the mixture was placed under a vacuum of 700 ± 50 mbar and then mixed at 10 rpm for 3 minutes and at 15 rpm for 10 minutes. In the second step, 2.8 kg of filler blend was added, the mixture was placed under a vacuum of 700 ± 50 mbar, and then mixed at 10 rpm for 3 minutes and at 15 rpm for 10 minutes. In the third step, 1.2 kg of filler blend was added, the mixture was placed under a vacuum of 700 ± 50 mbar, and then mixed at 10 rpm for 3 minutes and at 15 rpm for 10 minutes. In the fourth step, 0.9 kg of filler blend was added, the mixture was placed under a vacuum of 700 ± 50 mbar, and then mixed at 15 rpm for 25 minutes. In the fifth step, 0.7 kg of filler blend was added, the mixture was placed under a vacuum of 700 ± 50 mbar, and then mixed at 15 rpm for 25 minutes. In the sixth step, 0.4 kg of filler blend was added, the mixture was placed under a vacuum of 700 ± 50 mbar, and then mixed at 15 rpm for 25 minutes. In the seventh and eighth steps, the mixture was placed under a vacuum of 700 ± 50 mbar and then mixed at 12 rpm for 120 minutes. Then, the mixture was stored at 50 °C for 45 hours. Then, in the ninth step, it was placed under a vacuum of 220 ± 5 mbar at 48 °C and then mixed at 8 rpm for 20 minutes.

[0052] At 25 °C, 61.7 g of pigment, 24.4 g of YbF3, and 524 g of filler blend were added to this mixture. In the tenth step, the mixture was placed under a vacuum of 700 ± 50 mbar and then mixed at 15 rpm for 30 minutes. In the eleventh to thirteenth steps, the mixture was placed under a vacuum of 700 ± 50 mbar and then mixed at 15 rpm for 45 minutes. In the fourteenth step, the mixture was placed under a vacuum of 50 ± 5 mbar and then mixed at 8 rpm for 15 minutes. In the final step, the mixture was placed under a vacuum of 50 ± 5 mbar and then finally mixed at 5 rpm for 5 minutes.

[0053] Subsequently, the paste was automatically filled into small containers containing approximately 0.3 g of paste. From these containers, sample disks for the porosity test were prepared.

[0054] The method of Example 1 is shown in FIGS. 1a and 1b.

[0055] Example 2 At 25°C, in a 30 l container of a planetary mixer, 5.9 kg of a filler blend containing 55 wt% silanized glass filler and 45 wt% SphereTEC filler was added to 3.5 kg of a monomer mixture containing ethoxylated bisphenol dimethacrylate, triethylene glycol dimethacrylate, urethane dimethacrylate, and Ormosil-Resin, along with camphorquinone / ethyl 4-(dimethylamino)benzoate, butylated hydroxytoluene, 0.6 kg of YbF3.

[0056] In the first step, mixing was carried out at 10 rpm for 3 minutes and then at 15 rpm for 10 minutes. In the second step, 2.8 kg of the filler blend was added, and then mixing was carried out at 10 rpm for 3 minutes and at 15 rpm for 10 minutes. In the third step, 1.2 kg of the filler blend was added, and then mixing was carried out at 10 rpm for 3 minutes and at 15 rpm for 10 minutes. In the fourth step, 0.9 kg of the filler blend was added, and then mixing was carried out at 15 rpm for 25 minutes. In the fifth step, 0.7 kg of the filler blend was added, and then mixing was carried out at 15 rpm for 25 minutes. In the sixth step, 0.4 kg of the filler blend was added, and then mixing was carried out at 15 rpm for 25 minutes. In the seventh and eighth steps, mixing was carried out at 12 rpm for 120 minutes. Then, the mixture was stored at 50°C for 45 hours, and then, in the ninth step, it was placed under a vacuum of 220 ± 5 mbar at 48°C, and then mixing was carried out at 8 rpm for 20 minutes.

[0057] At 25 °C, 61.5 g of pigment, 24.6 g of YbF3, and 530 g of filler blend were added to this mixture. In the 10th step, the mixture was mixed at 15 rpm for 30 minutes. In the 11th to 13th steps, mixing was carried out at 15 rpm for 45 minutes. In the 14th step, the mixture was placed under a vacuum of 50 ± 5 mbar, and then mixing was carried out at 8 rpm for 15 minutes. In the final step, the mixture was placed under a vacuum of 50 ± 5 mbar, and then finally, mixing was carried out at 5 rpm for 5 minutes.

[0058] Subsequently, the paste was automatically filled into small containers containing approximately 0.3 g of the paste. From these containers, sample disks for porosity testing were prepared.

[0059] The method of Example 2 is shown in Figures 2a and 2b.

[0060] Example 3 Into 37.28 g of an active liquid containing a polymerizable monomer, an initiator, and a stabilizer in a container of an experimental planetary mixer, 55.23 g of particulate silanized filler, 2.24 g of fumed silica, and 398 mg of pigment were added.

[0061] In the first step, the mixture was heated to 50 °C, placed under a vacuum of 747 mbar, and then mixed at 40% power for 10 minutes.

[0062] In the second step, 33.13 g of particulate silanized filler was added, the mixture was placed under a vacuum of 752 mbar, and then mixed at 40% power for 10 minutes. The temperature was maintained at 50 °C.

[0063] In the third step, 16.57 g of particulate silanized filler was added, the mixture was placed under a vacuum of 750 mbar, and then mixed at 40% power for 10 minutes. The temperature was maintained at 50 °C.

[0064] In the fourth step, 5.52 g of particulate silanized filler was added, the mixture was placed under a vacuum of 749 mbar, and then mixed at 40% power for 10 minutes. The temperature was maintained at 50 °C.

[0065] In the 5th, 6th, and 7th steps, the mixture was placed under a vacuum of 739 - 745 mbar, and then mixed at 80% output for 30 minutes. The temperature was maintained at 50°C.

[0066] In the 8th step, the mixture was placed under a vacuum of 200 mbar, and then mixed at 40% output for 10 minutes. The temperature was maintained at 50°C.

[0067] The mixture was cooled to room temperature, and then a sample disk for porosity testing was prepared.

[0068] The method of Example 3 is shown in Figure 3.

[0069] Example 4 To 37.29 g of an active liquid containing a polymerizable monomer, an initiator, and a stabilizer in the container of an experimental planetary mixer, 55.23 g of particulate silanized filler, 2.25 g of fumed silica, and 398 mg of pigment were added.

[0070] In the first step, the mixture was heated to 50°C, and then mixed at 40% output for 10 minutes.

[0071] In the second step, 33.15 g of particulate silanized filler was added, and then mixed at 40% output for 10 minutes. The temperature was maintained at 50°C.

[0072] In the third step, 16.57 g of particulate silanized filler was added, and then mixed at 40% output for 10 minutes. The temperature was maintained at 50°C.

[0073] In the fourth step, 5.53 g of particulate silanized filler was added, and then mixed at 40% output for 10 minutes. The temperature was maintained at 50°C.

[0074] In the 5th, 6th, and 7th steps, mixing was carried out at 80% output for 30 minutes. The temperature was maintained at 50°C.

[0075] In the 8th step, the mixture was placed under a vacuum of 200 mbar and then mixed for 10 minutes at 40% output. The temperature was maintained at 50 °C.

[0076] The mixture was cooled to room temperature and then a sample disk for porosity testing was prepared.

[0077] The method of Example 4 is shown in Figure 4.

[0078] Example 5 To 123 g of an active liquid containing a polymerizable monomer, an initiator, and a stabilizer in the container of a laboratory planetary mixer, 3.68 g of fumed silica type "Aerosil" and 4.00 g of fumed silica type "Cab-O-Sil" were added.

[0079] In the first step, the mixture was heated to 40 °C, placed under a vacuum of 450 - 550 mbar, and then mixed for 10 minutes at output level 10.

[0080] In the second step, 173.69 g of particulate silanized filler was added, the mixture was placed under a vacuum of 450 - 550 mbar, and then mixed for 10 minutes at output level 15. The temperature was maintained at 40 °C.

[0081] In the third step, 141.41 g of SphereTEC filler was added, the mixture was placed under a vacuum of 450 - 550 mbar, and then mixed for 10 minutes at output level 15. The temperature was maintained at 40 °C.

[0082] In the fourth step, 61.48 g of YbF3 filler was added, the mixture was placed under a vacuum of 350 - 450 mbar, and then mixed for 10 minutes at output level 15. The temperature was maintained at 40 °C.

[0083] In the fifth step, the mixture was placed under a vacuum of 350 - 450 mbar and then mixed for 10 minutes at output level 18. During mixing, the temperature was maintained at 40 °C.

[0084] In the sixth step, 62.74 g of the active liquid containing the polymerizable monomer, initiator, and stabilizer was added, the mixture was placed under a vacuum of 350 - 450 mbar, and then mixed at an output level of 15 for 10 minutes. The temperature was maintained at 40°C.

[0085] In the seventh step, 30 g of the active liquid containing the polymerizable monomer, initiator, and stabilizer was added, the mixture was placed under a vacuum of 300 - 400 mbar, and then mixed at an output level of 15 for 10 minutes. The temperature was maintained at 40°C.

[0086] In the eighth step, the mixture was placed under a vacuum of 300 - 400 mbar, and then mixed at an output level of 18 for 10 minutes. During mixing, the temperature was maintained at 40°C.

[0087] In the ninth step, the mixture was placed under a vacuum of 300 - 400 mbar, and then mixed at an output level of 21 for 30 minutes. During mixing, the temperature was maintained at 40°C.

[0088] In the final step, the mixture was placed under a vacuum of 210 mbar, and then mixed at an output level of 15 for 15 minutes. During mixing, the temperature was maintained at 40°C.

[0089] The mixture was cooled to room temperature, and then a sample disk for porosity testing was prepared.

[0090] The method of Example 5 is shown in Figure 5.

[0091] Example 6 In the container of an experimental planetary mixer, 3.68 g of fumed silica type "Aerosil" and 4.00 g of fumed silica type "Cab - O - Sil" were added to 123 g of the active liquid containing the polymerizable monomer, initiator, and stabilizer.

[0092] In the first step, the mixture was heated to 40°C, and then mixed at an output level of 10 for 10 minutes.

[0093] In the second step, 173.69 g of particulate silanized filler was added, and then mixing was carried out at an output level of 15 for 10 minutes. The temperature was maintained at 40 °C.

[0094] In the third step, 141.41 g of SphereTEC filler was added, and then mixing was carried out at an output level of 15 for 10 minutes. The temperature was maintained at 40 °C.

[0095] In the fourth step, 61.48 g of YbF3 filler was added, and then mixing was carried out at an output level of 15 for 10 minutes. The temperature was maintained at 40 °C.

[0096] In the fifth step, the mixture was mixed at an output level of 18 for 10 minutes at a temperature of 40 °C.

[0097] In the sixth step, 62.74 g of active liquid containing a polymerizable monomer, an initiator, and a stabilizer was added, and then mixing was carried out at an output level of 15 for 10 minutes. The temperature was maintained at 40 °C.

[0098] In the seventh step, 30 g of active liquid containing a polymerizable monomer, an initiator, and a stabilizer was added, and then mixing was carried out at an output level of 15 for 10 minutes. The temperature was maintained at 40 °C.

[0099] In the eighth step, the mixture was mixed at an output level of 18 for 10 minutes at a temperature of 40 °C.

[0100] In the ninth step, the mixture was mixed at an output level of 21 for 30 minutes at a temperature of 40 °C. In the final step, the mixture was placed under a vacuum of 210 mbar and then mixing was carried out at an output level of 15 for 15 minutes. During mixing, the temperature was maintained at 40 °C.

[0101] The mixture was cooled to room temperature and then a sample disk for porosity testing was prepared.

[0102] The method of Example 6 is shown in Figure 6.

[0103] Example 7 1. Sample Preparation Place the composite material in the center of a Teflon mold with a thickness of 0.55 ± 0.05 mm, and cover the bottom and top with Mylar foil. Then, using a glass plate, press the material until the mold is completely filled. Carefully place the test sample including the foil between slide glasses, fix it with a clamp, and place it vertically in the holder for the LicuLite curing experiment. Cure each slide of the sample for 1 minute, and then remove the cured disk from the mold.

[0104] 2. Porosity analysis Place the sample disk under a microscope and take a photo using the image software "VLC media player" equipped with the driver "Blackmagic Design Desktop video 9.5.3" or the image software "Grab IT".

[0105] Then, use the software "dhs Bilddatenbank" to automatically count the bubbles according to their size.

[0106] The specifications of the bubbles are as follows:

[0107]

Table 1

[0108]

Table 2

[0109] Figures 7.1 to 7.3 show the results of the above porosity test as follows:

[0110]

Table 3

[0111] In other words, the results of the porosity test clearly and undoubtedly demonstrate that the composite material produced by the method in which a vacuum is applied to the mixing vessel before each individual mixing step has a much lower level of porosity when compared to the composite material produced by the method in which the same steps and conditions are used but the vacuum is set immediately before the last step or immediately before the last two steps.

Claims

1. A method for manufacturing a composite material, comprising the following steps in the following order: a. introducing a monomer mixture into a mixing vessel; b. introducing a part of a glass filler or a blend of glass fillers into the mixing vessel to produce a mixture, placing the mixture under vacuum, and mixing the mixture; c. introducing another part of the glass filler or the blend of glass fillers into the mixing vessel to produce a mixture, placing the mixture under vacuum, and mixing the mixture; d. placing the mixture under vacuum and mixing it to produce a paste; e. storing the paste at a high temperature; f. placing the paste under vacuum and mixing the paste to produce a composite material, and optionally g. adding at least one pigment, and optionally a glass filler or a blend of glass fillers and / or a monomer mixture to the composite material to produce a mixture, placing the mixture under vacuum, and mixing the mixture to produce a composite material wherein the monomer mixture comprises one or more polymerizable monomers, a polymerization initiator, and a polymerization stabilizer, and the one or more polymerizable monomers are selected from the group comprising acrylates and methacrylates.

2. the vacuum in steps b., c., and d. is 650 - 800 mbar, the mixing in step b. is carried out at a temperature of 23 - 27 °C at a speed of 8 - 12 rpm for 2 - 5 minutes, and then at a speed of 13 - 16 rpm for 8 - 12 minutes, whereby the step can be carried out 1 - 5 times, the mixing in step c. is carried out at a temperature of 23 - 27 °C at a speed of 12 - 16 rpm for 22 - 27 minutes, whereby the step can be carried out 1 - 4 times, the mixing in step d. is carried out at a temperature of 23 - 27 °C at a speed of 10 - 14 rpm for 110 - 130 minutes, whereby the step can be carried out 1 - 3 times, the storage in step e. is carried out at a temperature of 45 - 55 °C for 36 - 50 hours under anaerobic conditions, the vacuum in step f. is a vacuum of 210 - 230 mbar, and the mixing in step f. is carried out at a temperature of 46 - 48 °C at a speed of 6 - 10 rpm for 18 - 22 minutes. The mixing in step g. of the process is carried out at a temperature of 23 to 27 °C at a speed of 5 to 15 rpm in at least three steps, whereby each of said steps lasts 5 to 45 minutes and a vacuum of 45 to 800 mbar is set before each individual mixing step starts, according to the method of claim 1.

3. The following steps: a. A step of introducing the monomer mixture into the mixing vessel; b. A step of introducing the first part of the glass filler or the blend of glass fillers into the mixing vessel to produce a mixture, placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 °C at a speed of 10 rpm for 3 minutes and then at a speed of 15 rpm for 10 minutes; c. A step of introducing the second part of the glass filler or the blend of glass fillers into the mixing vessel to produce a mixture, placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 °C at a speed of 10 rpm for 3 minutes and then at a speed of 15 rpm for 10 minutes; d. A step of introducing the third part of the glass filler or the blend of glass fillers into the mixing vessel to produce a mixture, placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 °C at a speed of 10 rpm for 3 minutes and then at a speed of 15 rpm for 10 minutes; e. A step of introducing the fourth part of the glass filler or the blend of glass fillers into the mixing vessel to produce a mixture, placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 °C at a speed of 15 rpm for 25 minutes; f. A step of introducing the fifth part of the glass filler or the blend of glass fillers into the mixing vessel to produce a mixture, placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 °C at a speed of 15 rpm for 25 minutes; g. A step of introducing the sixth part of the glass filler or the blend of glass fillers into the mixing vessel to produce a mixture, placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 °C at a speed of 15 rpm for 25 minutes to produce a mixture; h. A step of placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 °C at a speed of 12 rpm for 120 minutes to produce a mixture; i. A step of placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 °C at a speed of 12 rpm for 120 minutes to produce a paste. j. A step of storing the paste at a temperature of 50 ° C for 36 to 48 hours under anaerobic conditions, k. A step of placing the paste under a vacuum of 220 mbar in the mixing container and mixing it at a temperature of 48 ° C at a speed of 8 rpm for 20 minutes to produce a composite material, and optionally l. Adding at least one pigment and optionally a glass filler or a blend of glass fillers and / or a monomer mixture to the composite material to produce a mixture, placing the mixture under a vacuum of 700 mbar, and mixing it at a temperature of 25 ° C at a speed of 15 rpm for 30 minutes, m. A step of placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 ° C at a speed of 15 rpm for 45 minutes, n. A step of placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 ° C at a speed of 15 rpm for 45 minutes, o. A step of placing the mixture under a vacuum of 700 mbar and mixing it at a temperature of 25 ° C at a speed of 15 rpm for 45 minutes, p. A step of placing the mixture under a vacuum of 50 mbar and mixing it at a temperature of 25 ° C at a speed of 8 rpm for 15 minutes, q. A step of placing the mixture under a vacuum of 50 mbar and mixing it at a temperature of 25 ° C at a speed of 5 rpm for 5 minutes to produce a composite material The method according to claim 2, comprising:

4. The method according to any one of the preceding claims, wherein the polymerization initiator is one or more compounds selected from the group consisting of initiators induced by visible light and ultraviolet light, which may or may not contain at least one further hydrogen donor and contain an alpha-diketone.

5. The method according to any one of the preceding claims, wherein the polymerization initiator comprises camphorquinone and ethyl 4-(dimethylamino)benzoate.

6. The method according to any one of the preceding claims, wherein the polymerization stabilizer is selected from the group consisting of butylated hydroxytoluene, hydroquinone monomethyl ether, tert.-butylhydroquinone, tert.-butylhydroxyanisole, 2,6-di-tert.-butyl-p-cresol, tetramethylpiperidine N-oxyl radical, and galvinoxyl radical.

7. The method according to any one of the preceding claims, wherein the glass filler is a silanized glass filler.

8. The method according to claims 1 to 7, wherein the mixing container is a planetary mixer or a centrifugal mixer.

9. A composite material comprising one or more polymerizable monomers, a polymerization initiator, a polymerization stabilizer, and a glass filler or blend of glass fillers, having a number of bubbles of size L less than 20, a number of bubbles of size M less than 100, and a number of bubbles of size M+L less than 120, wherein size M is from 70 to 140 μm and size L is from 140 to 1000 μm.

10. A composite material comprising one or more polymerizable monomers, a polymerization initiator, a polymerization stabilizer, and a glass filler or blend of glass fillers, having a number of bubbles of size L less than 5, a number of bubbles of size M less than 20, a number of bubbles of size S less than 300, a number of bubbles of size XS less than 200, and a number of bubbles of size L+M+S+XS less than 500, wherein size M is from 70 to 140 μm, size L is from 140 to 1000 μm, size S is from 30 to 70 μm, and size XS is from 0 to 30 μm.

11. The composite material according to claims 9-10, for use in the dental industry.

12. The composite material according to claims 9-10, for use in manufacturing a composite resin, temporary filling material, resin cement, adhesive, or fissure sealant.

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