JP2008222665A - Dental silicone-based curable material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a high-strength dental silicone-based curable material having excellent operation efficiency without increasing paste viscosity even when silica is increased. <P>SOLUTION: The dental silicone-based curable material is obtained by including hydrophobized silica having 100-2,000 nm primary particle diameter, preferably hydrophobized dry silica in a silicone-based curable material comprising an organopolysiloxane (A) having ≥2 organic groups having an unsaturated bond at the terminal in the molecule, an organohydrogenpolysiloxane (B) having ≥3 SiH groups in the molecule and a hydrosilylation reaction catalyst substance (C). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dental curing composition comprising a dental silicone-based curable material.

  Examples of the dental silicone-based curable material include a denture base lining material and a dental impression material. In either case, the surgeon measures and kneads the necessary amount immediately before use, and cures through appropriate treatment and processing. Such dental silicone-based curable materials mainly include condensation-reactive silicone-based curable materials and addition-reactive silicone-based curable materials depending on the curing reaction.

  The former has a hydroxyl group as a reactive group and cures by causing a condensation reaction in the course of the reaction. However, there is a drawback in that there is a leaving substance such as alcohol. The latter has a vinyl group and a SiH group as reactive groups, which are cured by an addition reaction during the reaction process, and are useful because there is no special detachment. Many curable materials are used.

  In recent years, dental silicone-based curable materials have been increasingly used for a long time with changes in treatment methods. Therefore, what has high durability is required, and high strength is desired. Currently, as a method for imparting high strength to a dental silicone-based curable material, a technique of adding hydrophobized finely divided silica as a filler is used (for example, see Patent Document 1). However, dry silica, which is generally widely used for such applications, has a primary particle size of about 10 to 50 nm (see, for example, Non-Patent Document 1). However, when this hydrophobized silica is increased, the strength is increased. Although it goes up, it has a drawback that the viscosity of the paste obtained by kneading is remarkably increased and the operability is lowered.

  Moreover, the dental silicone-based curable material is suitably used as a soft denture lining material. Soft denture lining material is a material that backs dentures that are incompatible with the oral mucosa, and is a part that directly contacts the oral mucosa in the oral cavity and also has a role to hold the denture in the oral cavity .

  Conventionally, as such soft denture lining materials, poly (meth) acrylate-based materials (see, for example, Patent Document 2) and silicone rubber-based materials (for example, see Patent Document 3) are known. Yes. A poly (meth) acrylate-based soft denture lining material generally contains a polymerized cured product of a (meth) acrylate-based radical polymerizable monomer such as methyl methacrylate or ethyl methacrylate. Typical product forms consist of a liquid material mainly composed of (meth) acrylate monomers and a powder material mainly composed of (meth) acrylate polymers such as polymethyl methacrylate. Furthermore, a polymerization initiator is appropriately distributed and mixed in the liquid material and the powder material, and the (meth) acrylate monomer is polymerized by mixing both materials. The (meth) acrylate polymer acts as a kind of filler, and dissolves or swells in the (meth) acrylate monomer at the time of mixing, and has the effect of making the entire composition into a paste or bowl shape. As a result, moderate operability can be obtained.

  Such a poly (meth) acrylate-based polymer cured product is excellent in strength, but does not have the necessary flexibility as a soft denture lining material as it is, so it is necessary to add a plasticizer. As such plasticizers, plasticizers such as dioctyl phthalate and dibutyl phthalate are mainly used.

  On the other hand, since silicone rubber is inherently highly biocompatible, silicone rubber-based soft denture lining materials are also widely used. In general, since silicone rubber is a soft material rich in elasticity, such a silicone rubber-based soft denture lining material does not require any additional plasticizer. As a result, dental silicone-based curable materials are often used as soft denture lining materials, but as described above, increasing the hydrophobic silica to increase the strength increases the strength, The paste obtained by kneading has a drawback that the viscosity is remarkably increased and the operability is lowered, and improvement is desired.

JP-A-10-279806 JP 10-236913 Japanese Patent No. 3478521 Nobuyuki Okada, supervised by Shinroku Saito, “Ultrafine Particles Handbook”, Fuji Techno System Co., Ltd., September 5, 1990, p. 755

  In view of the above background, the present invention has an object to develop a dental silicone-based curable material that has a high paste strength that maintains a low paste viscosity even when silica is increased and that has excellent operability. .

  As a result of intensive studies to solve the above problems, the present inventors have added hydrophobic silica having an average primary particle size of 100 to 2000 nm to a dental silicone-based curable material, while keeping the paste viscosity low. And it discovered that a high-strength dental silicone type curable material could be obtained, and came to complete this invention.

  That is, the present invention is a dental silicone-based curable material characterized by containing hydrophobized silica having an average primary particle size of 100 to 2000 nm.

  The dental silicone-based curable material in the present invention is characterized by containing hydrophobized silica having an average primary particle size of 100 to 2000 nm, and has a high strength of the cured product and a low paste viscosity. Has a remarkable effect.

  The present invention is characterized in that hydrophobized silica having an average primary particle size of 100 to 2000 nm is contained in a dental silicone-based curable material. The hydrophobized silica is blended for the purpose of a filler or the like for giving sufficient strength without reducing the flexibility of the dental silicone-based curable material.

  As described above, as a filler having a large reinforcing effect on the silicone-based curable material, fine silica, that is, silica-based particles having a large surface area has been found to be effective, and these silica-based particles are highly hydrophilic, It is used after being hydrophobized. As such fine silica, dry silica is often used, and these usually have a primary particle diameter of about 10 to 50 nm. However, when such a hydrophobized silica having an extremely fine particle size is used, there arises a problem of an increase in paste viscosity of the curable material as described above.

  On the other hand, when using the hydrophobized silica having an average particle diameter of the primary particles of 100 to 2000 nm, an increase in the paste viscosity of the curable material is greatly suppressed, and its operability is maintained well. On the other hand, when the particle size is increased to such a level, the strength of the cured body is maintained within a practically acceptable range. From the viewpoint of improving both the strength of the cured product and the low paste viscosity, the average particle size of the primary particles of the hydrophobized silica to be contained is preferably 150 to 1500 nm, and preferably 300 to 1000 nm. Is particularly preferred.

  Here, in the present invention, the primary particle diameter of the hydrophobized silica is a particle diameter measured by magnifying an image using a scanning electron microscope (SEM), and is the longest diameter. The average particle size may be determined as an average value of 30 or more arbitrarily extracted particles, more precisely 100 or more particle sizes in the measurement by the above method.

When the average particle diameter of the primary particles is smaller than 100 nm, the increase in paste viscosity of the curable material is increased. On the other hand, when the average particle diameter of the primary particles is larger than 2000 nm, the strength of the obtained cured body is satisfactory. Decreases to an impossible value. In addition, it is common that the hydrophobized silica in the range of the average particle diameter of such primary particles usually has a specific surface area in the range of 1.5 to 30 m ² .

  In the present invention, the hydrophobized silica may be any silica hydrophobized. Examples of such raw silica include wet silica, dry silica, and fused silica. Compared with silica obtained by wet silica or the like, dry silica is preferable because it has a small amount of surface silanol groups and is easily hydrophobized, and has low aggregation and high dispersibility.

  For example, in the case of fused silica, the silica having an average primary particle size of 100 to 2000 nm is manufactured by a method in which silica fine powder is melted in a flame and a method in which silicon fine powder is oxidized and melted in a flame. Of these, those having the above average particle diameter may be selected and used. Furthermore, when it obtains with the said dry silica, it can manufacture by adjusting the kind of organosilane, and the quantity of hydrogen and air in the method described in Sho-ko 56-38526. That is, it can be obtained by a method in which a mixture of liquid organosilane evaporated in an evaporator and hydrogen and air is supplied to a combustion chamber, and the combustion gas is reacted with an oxygen-containing gas.

  At this time, in order to produce the primary particles having an average particle diameter of 100 to 2000 nm, it is necessary to increase the amount of hydrogen and decrease the amount of air. Specifically, the amount of hydrogen is 0.3 to 1.2 times the amount of air, more preferably 0.5 to 1.0 times the range of the average particle diameter of the primary particles. Can be obtained.

  As the organosilane, known ones can be used without particular limitation, and examples thereof include methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, and trimethylcholorosilane. Of these, it is possible to use an organosilane having a large number of carbon atoms of an organic group bonded to one silicon atom, or a mixture with an organosilane having a large number of carbon atoms. It is more preferable for obtaining silica having an average particle size of 100 to 2000 nm. The number of carbon atoms is preferably 1.5 or more per one silicon atom.

  The hydrophobized silica is one having a modified hydrophobicity defined below of 60% or more. The modified hydrophobicity is defined as the methanol concentration (percentage by volume) in an aqueous solution having the lowest methanol content in an aqueous methanol solution containing 50 ml of water capable of completely suspending 0.2 g of silica-based particles. From the viewpoint of improving dispersibility in the silicone-based curable material and improving the strength of the cured product, the modified hydrophobicity is preferably 65% or more. The modified hydrophobicity is preferably as high as possible, but since it is difficult to obtain a modified hydrophobicity of 100% in production, the upper limit is usually about 95%.

  The method for hydrophobizing silica to achieve such modified hydrophobicity is not particularly limited, but can be suitably produced by a known surface treatment method. For example, it is a method of bringing the raw material silica into contact with an appropriate surface treatment agent once or twice or more in the presence of water vapor. Use raw silica that has not been absorbed by moisture immediately after the reaction of silica produced by the method for producing dry silica having an average particle size used in the present invention, or that that has been stored avoiding moisture absorption. That's fine. Examples of the surface treatment agent include hexamethyldisilazane, monomethylchlorosilane, trimethylcholorosilane, dimethylchlorosilane and the like.

  In the present invention, the amount of the hydrophobized silica is 100 parts by mass of polysiloxane constituting the dental silicone curable material (for example, an addition reaction type silicone curable material suitably used in the present invention described later). For example, it is 1-60 mass parts with respect to a component (A) and a component (B) total amount 100 weight part), Preferably it is 20-40 mass parts.

  In addition to the hydrophobized silica having an average primary particle size of 100 to 2000 nm, the hydrophobized silica having an average particle size other than 100 to 2000 nm, or other than the hydrophobized silica as long as the physical properties are not significantly affected. For example, silica-based powder such as pulverized quartz, diatomaceous earth, polyorganosilsesquioxane fine particles, aluminum oxide, aluminum silicate, iron oxide, zinc oxide, calcium carbonate, zirconium oxide, carbon black, etc. good. The blending amount of these other fillers is preferably within 10% by mass, more preferably within 3% by mass.

  Next, in the present invention, the dental silicone-based curable material containing such hydrophobic silica contains an organopolysiloxane as a main component, and causes a crosslinking reaction to form a silicone-based cured product. Materials are subject to restriction. Among them, as a silicone-based curable material for dental use, a material that can be easily cured in about 10 minutes at room temperature is useful for application to a dental material. Alternatively, an addition reaction type silicone curable material that cures by addition reaction is suitable. In particular, the latter is more preferable because there is no by-product such as alcohol and there is no polymerization heat during curing.

  As the addition reaction type silicone-based curable material, usually, an organopolysiloxane (hereinafter referred to as component (A)) having two or more organic groups having an unsaturated bond at the terminal, and three in the molecule. A material comprising an organohydrogenpolysiloxane having the above SiH group (hereinafter referred to as component (B)) and a hydrosilylation reaction catalyst material (hereinafter referred to as component (C)) is used. In this addition reaction type silicone-based curable material, the organopolysiloxane (A) having at least two organic groups having an unsaturated bond at the terminal of the component (A) is an organic group having an unsaturated bond at the terminal. As long as it is an organopolysiloxane having at least two per molecule, the structure of other organic groups present in the molecule is not limited, and may be linear or branched. It may be a mixture of

  Examples of the organic group having an unsaturated bond at the terminal present in the component (A) molecule include a vinyl group, an allyl group, a 1-butenyl group, and an ethynyl group. Most preferred is a vinyl group attached to an atom. These organic groups having terminal unsaturated bonds may be present at the end or in the middle of the molecular chain of the organosiloxane, or both, but the cured elastic body has excellent physical properties. In order to have properties, at least one is preferably present at the end of the molecule.

  Examples of the organic group bonded to the silicon atom other than the organic group having an unsaturated bond at the above-described end present in the component (A) molecule include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, and an octyl group. Group, aryl group such as phenyl group, substituted alkyl group such as chloromethyl group, 3,3,3-trifluoropropyl group, etc. are exemplified, but among these, it is easy to synthesize and has good physical properties after curing A methyl group is most preferred from the viewpoint of imparting properties.

  The number of siloxane units constituting the molecule of component (A) (corresponding to the degree of polymerization) is not particularly limited, but has suitable properties as a dental silicone-based curable material, that is, has an appropriate hardness after curing, In order to obtain sufficient elongation and mechanical strength, the number of the siloxane units is preferably 50 to 5000, particularly 100 to 2000.

  If the typical thing of the component (A) used for this invention is shown concretely,

(However, Ph represents a phenyl group)
The organopolysiloxane shown by these is mentioned. Note that the order of bonding of the repeating structural units in the above-mentioned compounds and the compounds used in the examples and comparative examples described later is completely arbitrary, and the number of repeating structural units shown in the structural formula is simply the total amount of each structural unit. It is only an average.

  The organohydrogenpolysiloxane (B) having at least three SiH groups in the molecule of the component (B) in the present invention is a component having a function of crosslinking the component (A) to form a rubber elastic body. In order to react with the component (A) to form a crosslinked structure, at least three SiH groups are required in the molecule. When the number is less than 3, a crosslinked structure is not obtained and sufficient curing does not occur.

  The structure of the component (B) is not particularly limited as long as it has 3 or more SiH groups in the molecule. The organic group bonded to the silicon atom other than the hydrogen atom present in the component (B) molecule is not particularly limited, and the organic group present in the molecule of the component (A) (having an unsaturated group at the terminal) The methyl group is most preferable because it is easy to synthesize and gives good physical properties after curing. Such component (B) may be linear, branched or cyclic, or a mixture thereof.

  The number of siloxane units constituting the molecule of component (B) (corresponding to the degree of polymerization) is not particularly limited, but in order to obtain a uniform cured product by quickly dispersing, the number of siloxane units is 2 to 200, especially The number is preferably 10 to 100.

  If the typical thing of the component (B) used for this invention is shown concretely,

The organohydrogenpolysiloxane shown by these is mentioned. Also in the components used in the above-mentioned compounds and Examples and Comparative Examples described below, the bonding order of each repeating structural unit in the molecule is completely arbitrary as in the case of Component (A).

  In such a silicone-based curable material, the blending ratio of the components (A) and (B) is not particularly limited as long as it is sufficiently cured, but expresses an appropriate elastic strain as a dental silicone-based curable material. Therefore, the ratio is preferably such that the total number of hydrogen atoms of the SiH group of component (B) is 0.5 to 5 times the total number of terminal unsaturated bonds of component (A). This is because if the total number of hydrogen atoms of the SiH group of component (B) is too small relative to the total number of terminal unsaturated groups of component (A), the curability may be insufficient, and too much. In some cases, excessive hydrogen atoms of the SiH group remain, so that foaming or aging may occur due to hydrogen generation during curing. Therefore, it is desirable that the ratio be such that the total number of SiH group hydrogen atoms in component (B) is 2 to 4 times the total number of terminal unsaturated bonds in component (A).

  In addition, organopolysiloxanes that contain only one organic group with an unsaturated bond at the end and organohydrogenpolysiloxanes that contain less than three SiH groups in the molecule within a range that does not significantly affect the physical properties. Siloxane may be added.

  The component (C) hydrosilylation reaction catalyst used in the present invention can be used without limitation as long as it is used in ordinary hydrosilylation reactions. For example, chloroplatinic acid, its alcohol-modified product, platinum vinylsiloxane A complex etc. can be mentioned. In order to improve the storage stability, a material having a small amount of chloro such as a platinum-vinylsiloxane complex is preferable.

  The amount of component (C) to be blended is not particularly limited, but generally it may be in the range of 0.1 to 1000 ppm based on the total weight of component (A) and component (B) in terms of platinum weight. When the blending amount is less than 0.1 ppm, the crosslinking reaction between the unsaturated bond-containing silicone of component (A) and the SiH siloxane of component (B) does not proceed sufficiently, and when it exceeds 1000 ppm, platinum black is deposited. When the cured product is yellow or severe, it tends to cause problems such as black coloration or difficulty in controlling the crosslinking reaction.

  In the above, the silicone-based curable material has been described in detail as an addition reaction type. However, when a condensation reaction type silicone curable material is used, the condensation reaction type has a hydroxyl group as a reactive group. Any known curable material in which the organopolysiloxane is cured by causing a condensation reaction in the reaction process can be used without limitation (for example, disclosed in JP-A-2004-182823).

  High molecular weight polyorganosiloxane raw rubber, paraffin wax, and the like can be added to the dental silicone-based curable material in this patent. Furthermore, black platinum or fine palladium can be added as a hydrogen gas absorbent as required.

  Moreover, you may add another additive in the range which does not reduce the physical property remarkably. Such additives include reaction inhibitors, ultraviolet absorbers, plasticizers, pigments, antioxidants, antibacterial agents and the like.

  The product form of the dental silicone-based curable material of the present invention having the above composition should be separately packaged so that the curing reaction will start when it coexists so that the curing reaction does not occur during storage. desirable. For example, in the case of the addition reaction type silicone-based curable material suitably used in the present invention, the component (A), the component (B), and the component (C) usually do not coexist at the same time (that is, during storage). Hydrosilation reaction does not occur), for example, a hydrophobized silica component, component (A), component (C), and paste a containing additives as necessary, and hydrophobized silica component, component (A) component ( It is preferable to prepare as a two-packaging type comprising B) and, if necessary, a paste b containing an additive, and to use a product form in which both are mixed immediately before use. As a method for producing the pastes a and b, an appropriate amount of necessary components can be weighed and kneaded until uniform using a general kneader such as a kneader or a planetary mixer.

  The dental silicone-based curable material of the present invention is used as a dental material. The silicone-based curable material can be widely used from a soft material to a relatively hard material by changing its components.

  Among these, the most suitable use in the dental silicone-based curable material in the present invention is a dental soft denture lining material. Here, as the soft denture lining material, usually, the Shore A hardness of the hardened body is 50 or less, and 45 or less is more preferably used.

  As described above, such a soft denture lining material is required to have a high durability due to a prolonged use period, and high strength is desired. As described above, the silicone-based curable material of the present invention has high strength by incorporating hydrophobic silica having an average primary particle diameter of 100 to 2000 nm, and is particularly useful for this application. is there.

  The soft denture lining material also includes a mucosa-adjusting material from a particularly flexible silicone rubber among silicone resins.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

  The properties of hydrophobized silica (silica 1-6, control: silica 7-9) used in the following examples and comparative examples are shown in Table 1, organopolysiloxane 1 (component A: compounds A-1 to A-5, Table 2 shows the structure and viscosity of those having a hydroxyl group in the molecule: A-6). Table 2 shows organopolysiloxane 2 (component B: compounds B-1, B-3 to B-5, and two SiH groups in the molecule). Table 3 shows the structure of Compound B-2).

  Moreover, the following compounds were used as a catalyst. The structural formula of each compound is shown below.

  C-1: Vinylsiloxane complex of platinum (component C)

  C-2: Dibutyl dilauryl tin

  C-3: Tetraethoxysilane

  Each hydrophobized silica shown in Table 1 was obtained as follows.

(1) Hydrophobized silica 1 (dry silica):
A mixture of 1.5 kg / h of methyltrichlorosilane and 1.0 kg / h of tetramethylsilane was fed into the evaporator by a membrane plate piston pump having a pressure of 1.5 kg / cm ² . The evaporator had a heat generating surface, also called a heating surface, which was heated by 0.5 kg / cm ² of water vapor. The steam flow is controlled by a controller driven by the vapor pressure of methyltrichlorosilane in the evaporator so that a constant liquid level of liquid organosilane and a pressure of 0.5 kg / cm ² of methyltrichlorosilane are always maintained. To be adjusted.

  The conduit between the evaporator and the burner was equipped with a controller so that water vapor was heated by the coating flowing through it and the temperature was maintained.

In the burner, a mixture of methyltrichlorosilane 1.5 kg / h and tetramethylsilane 1.0 kg / h, mixed with hydrogen 0.5 Nm ³ / h and air 1.0 Nm ³ / h, the combustion through conical inlet By supplying to the chamber, dry silica having an average particle diameter of 500 nm was obtained.

  5 kg of this dry silica was put into a fluidized reactor, and it was hydrophobized by parallelly ventilating with nitrogen for 40 minutes in a fluidized bed reactor heated to 450 ° C. at 20 g / min of dimethyldichlorosilane and 180 g / min of water vapor. Processed. After the hydrophobization treatment, unreacted products and by-products were purged with nitrogen and dried. 5 kg of the silica particles obtained by the above operation were mixed and expanded in a mixer having an internal volume of 300 L, and replaced with a nitrogen atmosphere. At a reaction temperature of 200 ° C., a hydrophobization treatment was performed by supplying hexamethyldisilazane at 200 g / min and steam at 11 g for 75 minutes. After the reaction, 40 L of nitrogen per minute was supplied for 30 minutes to perform deammonia treatment to obtain hydrophobic silica 1.

  (2) Hydrophobized silica 2 to 4 (dry silica): In the production method of hydrophobized silica 1, the same operation as in hydrophobized silica 1 was performed except that the conditions were changed to those shown in Table 4, and the hydrophobized silica 2 to 4 were obtained, respectively.

  (3) Hydrophobized silica 5 (dry silica): 5 kg of the hydrophobized silica particles obtained in the same manner as the hydrophobized silica 1 were mixed and sold in a mixer having an internal volume of 300 L, and the atmosphere was replaced with a nitrogen atmosphere. At a reaction temperature of 200 ° C., a hydrophobization treatment was performed by supplying hexamethyldisilazane at 200 g / min and steam at 11 g for 75 minutes. After the reaction, 40 L of nitrogen per minute was supplied for 30 minutes to perform deammonia treatment to obtain hydrophobized silica 5.

  (4) Hydrophobized silica 6 (wet silica): expressed by an average particle diameter of 500 nm immediately after production obtained by the method described in Experiment No. 5 of JP-A 63-112411, using wet silica. Otherwise, the hydrophobized silica 6 was obtained in the same manner as the hydrophobized silica 4 described above.

  (5) Hydrophobized silica 7 (dry silica): In the production method of hydrophobized silica 1, the same operation as in hydrophobized silica 1 was carried out except that the conditions were changed to those shown in Table 4 to obtain hydrophobized silica 7. .

  (6) Hydrophobized silica 8 (dry silica): fluidized bed reaction in which 5 kg of Leoroseal ZD30ST (manufactured by Tokuyama) was placed in a fluidized bed reactor and heated to 450 ° C. at 20 g / min of dimethyldichlorosilane and 180 g / min of water vapor. The vessel was insufflated with nitrogen for 40 minutes. After the hydrophobization treatment, unreacted substances and by-products were purged with nitrogen and dried to obtain hydrophobized silica 8.

  (7) Hydrophobized silica 9 (dry silica): By the same method as hydrophobized silica 1, dry silica represented by an average particle size of 500 nm was obtained. 5 kg of this dry silica was put into a fluidized bed reactor, and dimethyldichlorosilane was fed at a rate of 20 g / min and water vapor was heated at 180 g / min to 450 ° C., and was then co-flowed by nitrogen in a fluidized bed reactor for 40 minutes. . After the hydrophobization treatment, unreacted substances and by-products were purged with nitrogen and dried to obtain hydrophobized silica 9.

  The modified hydrophobicity was measured as follows. 0.2 g of hydrophobized silica was added to 50 ml water in a 250 ml beaker. Methanol was added dropwise from the burette until the entire amount of hydrophobized silica was suspended. At this time, the solution in the beaker was constantly stirred with a magnetic stirrer. The time at which the entire amount of hydrophobized silica was suspended in the solution was taken as the end point, and the volume percentage of methanol in the beaker liquid mixture at the end point was taken as the modified hydrophobicity.

  The average primary particle size of the hydrophobized silica was measured by taking a magnified image at 20000 times using a scanning electron microscope and averaging the particle size of 100 or more particles in the field of view.

  Further, in Examples 1 to 14 and Comparative Examples 1 to 3, the dental silicone-based curable material was evaluated by the following method, and the same sample was measured or evaluated three times and the average value was recorded.

  (1) Viscosity: A CS rheometer (CVO120HR, manufactured by BOHLIN) was used to knead and paste the necessary amounts of pastes a and b, and the viscosity was measured 15 seconds after the start of kneading. The measurement conditions are set mode: Oscillation, cone: Parallel Plate 20 mm, Gap: 1000 μm, set temperature: 23 ° C.

  (2) Tear strength: Take the required amount of each of pastes a and b, and after kneading, fill into a 2 mm thick stainless steel mold with (C) angle-shaped holes in JIS K 6252 and in the air And fully cured. After curing, it was taken out from the mold and left in water at 37 ° C. for 24 hours, and then the crosshead speed was 500 mm / min. By an autograph (manufactured by Shimadzu Corporation). The tear strength at the time of cutting was measured.

  (3) Shore A hardness: Necessary amounts of each of pastes a and b were taken, kneaded, filled into a polytetrafluoroethylene mold having a hole of 9 mm in diameter and 12 mm in length, and sufficiently cured in air. After curing, the product was taken out from the mold, left in water at 37 ° C. for 24 hours, and then measured with a Shore A hardness meter.

(4) Kneadability: Take necessary amounts of each of pastes a and b, knead by hand with a metal spatula until a total of 6 g is uniform, and knead the kneadability from ◎ to × according to the following criteria evaluated.
◎: Can be kneaded with light force, 15 seconds or less until uniform ○: Can be kneaded with light force, 15-20 seconds until uniform Δ: 20-30 seconds until uniform ×: A strong force is required for kneading, and it takes 30 seconds or more to become uniform Example 1
30 parts by mass of hydrophobized silica 1 shown in Table 1, 60 parts by mass of Compound A-1 shown in Table 2 as an organopolysiloxane having an unsaturated bond, 40 parts by mass of A-2, platinum compound C as a catalyst 200 ppm of -1 was put into a planetary mixer and kneaded until uniform to obtain paste a.

  30 parts by mass of hydrophobic silica 1 shown in Table 1, 55 parts by mass of polysiloxane compound A-1 having an unsaturated bond shown in Table 2 as organopolysiloxane, 37 parts by mass of A-2, and Table 3 1.9 parts by mass and B-25.6 parts by mass of the indicated organohydrogensiloxane compound B-1 were respectively added to a planetary mixer and kneaded until uniform to obtain paste b.

  The pastes a and b were kneaded at a mixing ratio of 1: 1, and the above physical properties were evaluated. The evaluation results are shown in Table 5.

  As shown in Table 5, it was found that the viscosity was 35 Pa · s, the viscosity was low and the kneading property was excellent, and the tear strength was as high as 18 N / mm. Here, as a guideline, the viscosity for obtaining excellent operability is 120 Pa · s or less. Furthermore, it was found that the hardness was 40 and a value that can be suitably used as a dental soft denture lining material. Here, it becomes a standard that the hardness which can be used conveniently as a dental soft denture lining material is 25-45.

Examples 2-13
The materials having the respective compositions shown in Tables 5 and 6 were kneaded in the same manner as in Example 1 to prepare pastes for evaluation. These evaluation results are shown in Table 5 and Table 6, respectively.
As shown in Tables 5 and 6 above, the dental silicone-based curable material of the present invention has excellent operability with a viscosity of 120 Pa · s or less, and a high tear strength of 10 N / mm or more. Was. Furthermore, the hardness was 25 to 45, which was a value that can be suitably used as a dental soft denture lining material.

Example 14
The materials having the respective compositions shown in Table 6 using the condensation reaction type silicone were kneaded in the same manner as in Example 1 to prepare each paste. Evaluation was performed in the same manner as in Example 1 except that the pastes a and b were kneaded at a mixing ratio of 1: 4. These evaluation results are shown in Table 6.

  As shown in Table 6 above, it was found that the viscosity was 30 Pa · s, the viscosity was low and the kneading property was excellent, and the tear strength was as high as 18 N / mm. Furthermore, the hardness was 40, which was a value that can be suitably used as a dental soft denture lining material.

Comparative Example 1
The materials having the compositions shown in Table 6 were kneaded in the same manner as in Example 1 to prepare each paste and evaluated. These evaluation results are shown in Table 6.

  As shown in Table 6, when the particle size of the hydrophobized silica is too large, the viscosity is low and the operability is excellent and the hardness is good, but the tear strength is very low and the high strength is It was not obtained.

Comparative Example 2
The materials having the compositions shown in Table 6 were kneaded in the same manner as in Example 1 to prepare each paste and evaluated. These evaluation results are shown in Table 6.
As shown in Table 6, when the particle size of the hydrophobized silica is too small, the tear strength is large and high strength can be obtained and the hardness is also good, but the viscosity becomes very high. An excellent operability was not obtained.

Comparative Example 3
The materials having the compositions shown in Table 6 were kneaded in the same manner as in Example 1 to prepare each paste and evaluated. These evaluation results are shown in Table 6.

  As shown in Table 6, when silica having a modified hydrophobicity smaller than the hydrophobized silica defined in this patent is used, not only high viscosity and excellent operability are obtained, but also the tear strength is reduced. High strength could not be obtained and the hardness was low.

Claims (5)

  A dental silicone-based curable material comprising hydrophobized silica having an average primary particle size of 100 to 2000 nm.   The dental silicone-based curable material according to claim 1, wherein the hydrophobized silica is hydrophobized dry silica.   The dental silicone-based curable material according to claim 1 or 2, wherein the dental silicone-based curable material is cured by an addition reaction.   Organopolysiloxane (A) having 2 or more organic groups having an unsaturated bond at the terminal, organohydrogenpolysiloxane (B) having 3 or more SiH groups in the molecule, and hydrosilylation reaction catalyst The dental silicone-based curable material according to claim 3, comprising a substance (C).   A dental soft denture lining material comprising the dental silicone-based curable material according to any one of claims 1 to 4.