JP5991880B2 - Powder-liquid type dental adhesive and dental adhesive kit using the same - Google Patents

Description

  The present invention relates to a powder liquid type dental adhesive, and more particularly, to a powder liquid type dental adhesive containing a dendritic polymer, and a dental adhesive kit using the same.

  In the field of dental treatment, a liquid material mainly composed of lower alkyl (meth) acrylate such as methyl methacrylate and a powder material mainly composed of non-crosslinked poly lower alkyl (meth) acrylate particles such as polymethyl methacrylate. A powder-type dental adhesive made in combination is used (see, for example, Patent Documents 1 to 3). In a powder liquid type dental adhesive, a chemical polymerization initiator composed of a plurality of components is usually blended into each of the liquid material and the powder material, and these liquid material and powder material are used at the time of use. Is generated to generate radicals, and radical polymerization of the lower alkyl (meth) acrylate is started. Further, when the liquid material and the powder material are mixed, a part of the non-crosslinked poly lower alkyl (meth) acrylate particles contained in the powder material is converted into the lower alkyl (meth) acrylate contained in the liquid material. It gradually dissolves to increase the viscosity of the mixed paste, improve its operability, and further promote the polymerization reaction.

  The cured product obtained as a result of such radical polymerization is tougher than the cured product containing an inorganic filler due to the action of non-crosslinked poly-lower alkyl (meth) acrylate particles. Further, since the lower alkyl (meth) acrylate is monofunctional and has good compatibility with non-crosslinked poly-lower alkyl (meth) acrylate particles, the toughness of the cured product is further improved. Therefore, the powder-type dental adhesive has a high resistance to the detachment of the prosthesis due to stress, and the tooth surface and the prosthesis are decalcified by applying a dental pretreatment material made of an aqueous solution of an acidic compound. By applying to objects, high adhesive strength can be exhibited. For this reason, it is widely used from a general bonding application to a case where high stress is applied after treatment, for example, orthodontic treatment or fixed tooth fixation.

JP 2009-221171 A JP 2009-1536 A JP 07-48219 A

  In this way, the powder type dental adhesive has high toughness and is used as an excellent adhesive for the tooth substance, but high stress is applied to the treated part of the tooth due to occlusion, etc. The adhesive strength is not sufficiently satisfactory, and further improvement has been desired. In particular, the polymerization of the radically polymerizable monomer inevitably generates polymerization shrinkage stress, and it has been a problem to relax this and increase the adhesive force.

  Further, the reason why the adhesive strength of the powder liquid type dental adhesive is not sufficient is that the polymerization activity of the lower alkyl (meth) acrylate is low, and in order to compensate for this, the non-crosslinked poly lower alkyl (meth) Although a device for increasing the viscosity by dissolving the acrylate particles has been devised, it has been desired to further increase the polymerizability thereof. In addition, the low polymerization activity of the lower alkyl (meth) acrylate has deteriorated the operability of dental treatment, and a short curing time has been demanded.

  In the background described above, the present invention has a low polymerization shrinkage stress and a high degree of polymerization of lower alkyl (meth) acrylate, and thus exhibits excellent adhesiveness to dental materials and prostheses, and also has an operability for treatment. The aim is to propose a good powder-type dental adhesive.

  The present inventors have intensively studied to achieve the above object. As a result, it has been found that the above problem can be solved by blending a dendritic polymer into the powder liquid type dental adhesive, and the present invention has been completed.

That is, the present invention relates to (A) a liquid material containing a lower alkyl (meth) acrylate as a main component, and (B) a non-crosslinked poly lower alkyl (meth) having a volume average particle diameter of 0.1 to 150 μm. A powder liquid type dental adhesive comprising a powder material containing acrylate particles as a main component, and a radical polymerization initiator is blended in at least one of the liquid material (A) and the powder material (B). In the material,
Further, the (A) liquid medium and (B) Ri to at least one of the powdery material name is blended is dendritic polymers, the amount of dendritic polymer contained in Konaeki dental adhesive comprises a liquid material in powder material obtained by mixing the paste, a Ru 11-91 parts by der powder-liquid type dental adhesive of the radical polymerizable monomer 100 parts by mass.

  The present invention also provides a dental adhesive kit comprising (I) a powder type dental adhesive and (II) a dental pretreatment material comprising an aqueous solution of an acidic compound.

  The powder liquid type dental adhesive of the present invention has a low polymerization shrinkage stress at the time of curing, and also has a high polymerization activity of a lower alkyl (meth) acrylate, and thus has a high adhesiveness to a tooth or a prosthesis. ing. Further, since the polymerization activity of the lower alkyl (meth) acrylate is high as described above, the curing at the time of mixing the liquid material and the powder material can be shortened, and the operability of treatment can be improved.

  The powder-type dental adhesive targeted by the present invention is mainly composed of (A) a liquid material containing lower alkyl (meth) acrylate as a main component, and (B) non-crosslinked poly lower alkyl (meth) acrylate particles. It is a material in which a powder material contained as a component is combined, and a radical polymerization initiator is blended in at least one of the (A) liquid material and (B) powder material. Hereafter, each component which comprises these (A) liquid materials and (B) powder materials is demonstrated sequentially.

  (A) The lower alkyl (meth) acrylate, which is the main component of the liquid material, has an alkyl chain having 4 or less carbon atoms. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, propyl ( Examples include meth) acrylate, isopropyl (meth) acrylate, and butyl (meth) acrylate. When such a lower alkyl (meth) acrylate is used, a tough product can be obtained as a cured product. The above lower alkyl (meth) acrylates may be used in combination of a plurality of types as appropriate, but in particular, since high toughness is obtained, it is optimal to use methyl (meth) acrylate as a main component. The blending amount of the lower alkyl (meth) acrylate in the liquid material is preferably 50% by mass or more, particularly preferably 60% by mass or more with respect to 100% by mass of the liquid material from the viewpoint of obtaining high toughness.

  As described above, these lower alkyl (meth) acrylates are monofunctional monomers and have low polymerization activity. Conventionally, when such a low-polymerizable lower alkyl (meth) acrylate is contained in a large amount (50% by mass or more, preferably 60% by mass or more) in the liquid material, the resulting powder liquid dental adhesive is cured. The time will be longer. However, in the present invention, since the polymerizability of the lower alkyl (meth) acrylate is increased by containing a resinous polymer as will be described later, it is possible to shorten the curing time of the powder type dental adhesive. It becomes possible.

  In the present invention, the liquid material (A) may contain other radical polymerizable monomers in addition to the lower alkyl (meth) acrylate as long as the physical properties of the powder liquid dental adhesive are not impaired. good. The content is generally 50% by mass or less, preferably 40% by mass or less, with respect to 100% by mass of the liquid material.

  As such other radically polymerizable monomers, conventionally known monomers can be used as long as they have at least one ethylenically unsaturated group in the molecule. As such an ethylenically unsaturated group, acryloyl can be used. Group, methacryloyl group, acrylamide group, methacrylamide group, styryl group and the like. Specific examples of other radical polymerizable monomers include 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, benzyl (meth) acrylate, allyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2 -(Meth) acryloxyethyl propionate, 2-methacryloxyethyl acetoacetate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, glyceryl mono (meth) acrylate, polyethylene glycol mono (meth) Monofunctional ones such as acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, Naethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4 -Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, neopentyl glycol di (meth) acrylate , Pentaerythritol tri (meth) acrylate, trimethylolmethane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, urethane (meth) acrylate, etc. Bis ((meth) acryloxyphenyl) propane, 2,2-bis [4- (2-hydroxy-3- (meth) acryloxyphenyl)] propane, 2,2-bis (4- (meth) acryloxyethoxy) Phenyl) propane, 2,2-bis (4- (meth) acryloxydiethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxypropoxyphenyl) propane, etc. 11- (meth) acryloyloxy-1,1-undecanedicarboxylic acid, 4- (meth) acryloyloxyethyl trimellitic acid and its anhydride, 2-methacryloyloxyethyl dihydrogen phosphate, bis (2-methacryloyloxy) Ethyl) hydrogen phosphate, 10-methacryloyloxydecyl dihydrogen Those containing acidic groups such as sulfate; those containing basic groups such as N, N-dimethylaminoethyl methacrylate; ω-methacryloyloxyhexyl 2-thiouracil-5-carboxylate, γ-methacryloxy Adhesive (meth) acrylates such as propyltrimethoxysilane; those containing (meth) acrylamide groups such as diacetone acrylamide and N-methylol (meth) acrylamide; styrene, α-methylstyrene derivatives; It is done. These radically polymerizable monomers can be used alone or in admixture of two or more.

  In addition, the (A) liquid material can contain various optional components as necessary within a range not impairing the effects of the present invention. Examples of such optional components include stabilizers such as polymerization initiators such as pH adjusters, strength regulators such as inorganic particles or organic particles, viscosity modifiers, various salts, ethanol, isopropanol, ethylene glycol, propanediol, Examples include organic solvents such as acetone, various fragrances, various antibacterial agents, various medicinal ingredients, pigments, dyes, and the like. In particular, it is preferable to add a small amount of a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, or 2,6-ditertiary butylphenol in order to improve storage stability and ambient light stability.

  Next, the powder material (B) constituting the powder liquid type dental adhesive will be described. (B) The powder material contains non-crosslinked poly lower alkyl (meth) acrylate particles as a main component. The poly-lower alkyl (meth) acrylate particles are non-crosslinked polymer particles obtained by homopolymerization or copolymerization of lower alkyl methacrylate having an alkyl chain having 4 or less carbon atoms. Specific examples of) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and the like.

  The non-crosslinked poly-lower alkyl (meth) acrylate particles are synthesized from the above-described lower alkyl (meth) acrylate as a raw material by bulk polymerization or suspension polymerization, etc. Resin powder can be used without any limitation. Examples of such non-crosslinked poly lower alkyl (meth) acrylate particles include polymethyl methacrylate particles, polyethyl methacrylate particles, polybutyl methacrylate particles, copolymer particles of methyl methacrylate and ethyl methacrylate, methyl methacrylate and butyl methacrylate. Examples thereof include copolymer particles and copolymer particles of ethyl methacrylate and butyl methacrylate. You may use these in mixture of 2 or more types. In particular, it is preferable to use polymethyl methacrylate particles, polyethyl methacrylate particles, and copolymer particles of methyl methacrylate and ethyl methacrylate since a toughened cured body can be obtained.

  The volume average particle diameter of such non-crosslinked poly-lower alkyl (meth) acrylate particles is not particularly limited, but is preferably not too large from the viewpoint of good compatibility between the powder material and the liquid material. From the viewpoint of improving the paste properties obtained by mixing the materials, it is preferable that the paste properties are not too small. From such a viewpoint, the volume average particle diameter of the non-crosslinked poly-lower alkyl (meth) acrylate particles is preferably 0.1 to 150 μm, and more preferably 5 to 80 μm. From the viewpoint of reducing the film thickness, the most preferred volume average particle diameter is in the range of 10 to 50 μm.

  In the present invention, the volume average particle diameter of the particles is a median diameter measured by a laser diffraction / scattering method. Specifically, a non-crosslinked poly lower alkyl (meth) acrylate particle such as ethanol or a mixed solvent of water and ethanol is dispersed well, and a dispersion medium in which the particle does not dissolve or swell is used. It is the value calculated | required by.

  Further, the shape of the non-crosslinked poly-lower alkyl (meth) acrylate particles is not particularly limited, and spherical to substantially spherical particles prepared by suspension polymerization or the like can be used. You may use the irregular-shaped particle | grains obtained by carrying out conventionally well-known grinding | pulverization processing of a spherical particle | grain etc., or an irregular-shaped grinding | pulverization particle. Such pulverization is performed by, for example, heating and fusing spherical non-crosslinked poly-lower alkyl (meth) acrylate particles obtained by a suspension polymerization method or the like, and using a ball mill or the like to machine the obtained fused particle lump. It can be easily prepared by pulverization.

  In the present invention, the specific surface area of the non-crosslinked poly lower alkyl (meth) acrylate particles is not particularly limited. However, when a material having a relatively large specific surface area is used, the solubility of the particles is increased with respect to a liquid material containing (A) a lower alkyl (meth) acrylate as a main component, The increase in the initial viscosity of the paste obtained by mixing the powder material can be accelerated. As a result, the polymerization activity of the lower alkyl (meth) acrylate is increased, and the curing time can be shortened.

From such a viewpoint, it is preferable that the specific surface area of the non-crosslinked poly-lower alkyl (meth) acrylate particles contained in the powder material (B) is 0.7 to 5.5 m ² / g. When the specific surface area of the non-crosslinked poly lower alkyl (meth) acrylate particles is larger than the above lower limit, (A) the solubility in the liquid material is particularly high, and the viscosity increase after mixing the liquid material and the powder material is accelerated. Therefore, higher polymerization activity can be obtained. On the other hand, since the specific surface area of the non-crosslinked poly-lower alkyl (meth) acrylate particles is smaller than the above upper limit, the solubility in the liquid material is not excessively increased, and the operability after mixing the liquid material and the powder material is good. Can be suppressed. From the viewpoint of better exhibiting this effect, the specific surface area of the non-crosslinked poly-lower alkyl (meth) acrylate particles is more preferably 0.9 to 4.5 m ² / g.

  In the present invention, the non-crosslinked poly-lower alkyl (meth) acrylate particles may be used by mixing a plurality of types having different resin types, volume average particle diameters, and shapes. In that case, all of the raw material particle types to be mixed may be used within the specified range of the specific surface area, but the specific surface area is adjusted within the above range as a mixture of non-crosslinked poly lower alkyl (meth) acrylate particles. If so, some of the raw material particle types may be used outside the specified range of the specific surface area.

  Specifically, in order to make the non-crosslinked poly-lower alkyl (meth) acrylate particles within the above specific surface area, a spherical or substantially spherical particle having a small particle size with a volume average particle size of 10 μm or less, preferably 5 μm or less. However, it is preferable to use a deformed particle or an irregularly shaped pulverized particle having a large specific surface area because it has a high solubility and a rapid increase in viscosity. That is, it is preferable to adjust the specific surface area within the above range by using particles having a large specific surface area as at least part of the non-crosslinked poly-lower alkyl (meth) acrylate particles. Spherical or substantially spherical particles and irregularly shaped particles or irregularly shaped pulverized particles may be appropriately mixed and used.

In the present invention, the specific surface area of the non-crosslinked poly-lower alkyl (meth) acrylate particles refers to a BET specific surface area value (m ² / g) by a nitrogen adsorption method. Specifically, it is a BET specific surface area value of non-crosslinked poly-lower alkyl (meth) acrylate particles dried in vacuum at 25 ° C. for 4 hours.

  (B) In the powder material, the blending ratio of the non-crosslinked poly lower alkyl (meth) acrylate particles is 40% by mass or more, particularly 60% by mass or more when the total of the powder material is 100% by mass. preferable.

  If the weight average molecular weight of the non-crosslinked poly-lower alkyl (meth) acrylate particles is too small, the toughness of the cured product is lowered, and sufficient cured product properties cannot be obtained. On the other hand, if the weight average molecular weight is too large, the viscosity increase after mixing is insufficient due to its slow solubility, and high curing activity cannot be obtained. From the viewpoint of better exhibiting this effect, the weight average molecular weight is preferably 10 to 1,200,000, and particularly preferably 15 to 1,000,000. Such a weight average molecular weight is measured as a molecular weight in terms of polystyrene using gel permeation chromatography.

  In addition, in the powder material (B), other filler components can be contained as necessary within a range not impairing the effects of the present invention. Examples of such other filler components include non-crosslinkable organic fillers other than poly lower alkyl (meth) acrylates, crosslinkable organic fillers, inorganic fillers, and organic-inorganic composite fillers. The non-crosslinkable organic filler other than the poly lower alkyl (meth) acrylate is an organic filler made of a resin having a structure having no crosslinked structure, and is a non-crosslinkable organic filler other than the conventionally known poly lower alkyl (meth) acrylate. Can be used without any restrictions. Specific examples include fillers such as polyethylene, polypropylene, polyamides, polyesters, and polystyrenes. Moreover, as a crosslinking filler, crosslinking | crosslinked fillers, such as bridge | crosslinking type polyalkyl (meth) acrylate and polystyrene, etc. can be used. Examples of the inorganic filler include quartz, silica, silica-alumina, silica-titania, silica-zirconia, titania, alumina, zirconia, fluoroaluminosilicate glass, barium glass, strontium glass, sodium fluoride, and the like (B ) In order to improve the compatibility with the non-crosslinked poly lower alkyl (meth) acrylate particles, the surface thereof can be coated with a conventionally known polymer, silane coupling agent or the like. An inorganic organic composite filler obtained by pulverizing a composite of an inorganic oxide and a polymer can also be used.

  The shape of the other filler component is not particularly limited, and may be pulverized particles or spherical particles obtained by normal pulverization. The particle diameter is not particularly limited, but the volume average particle diameter is preferably 150 μm or less, and particularly preferably 80 μm or less from the viewpoint of familiarity with the liquid material.

  (B) Various arbitrary components can be contained in the powder material as needed within a range not impairing the effects of the present invention. Examples of such optional components include polymerization accelerators, stabilizers, fluidity modifiers such as fumed silica, solid monomers, pigments, and dyes. In addition, the compounding quantity of a fumed silica is 1 mass% or less normally with respect to 100 mass% of (B) powder materials, Preferably it is 0.3 mass% or less.

  The greatest feature of the present invention is that, in such a powder liquid type dental adhesive, a dendritic polymer is blended in at least one of (A) liquid material and (B) powder material. Here, the dendritic polymer is a polymer that is highly branched by repeating a three-dimensional branching structure, while conventional polymers generally have a string-like (or linear) shape. Therefore, the dendritic polymer 1) has a shape close to a sphere, 2) has a size on the order of nanometers, 3) has little intermolecular entanglement, and exhibits fine particle behavior. 4) Compared with a string polymer. High dispersibility when mixed with a solvent or a liquid polymerizable monomer, and the increase in viscosity can be suppressed to a low level. 5) Having a large number of molecular chain terminals capable of introducing functional groups on the surface. 6) It has characteristics such as having a void in the molecule (between each branch). Thus, even in a liquid or paste composition containing a lower alkyl (meth) acrylate as a main component, the dendritic polymer can be easily incorporated into the composition without significantly increasing the viscosity of the composition. Can be finely dispersed. Dendritic polymers also have a high affinity for lower alkyl (meth) acrylates. From these, when a certain amount of the dendritic polymer is blended with either the liquid material or the powder material of the powder liquid type dental adhesive, the lower alkyl (meth) acrylate occupies the total paste obtained by mixing them. Combined with the effect of substantially reducing the amount of the polymer and the effect of affinity with the cured product of the lower alkyl (meth) acrylate, it is possible to reduce polymerization shrinkage at the time of curing, high adhesion to the tooth and prosthesis Sex is demonstrated.

  Furthermore, in the powder liquid type dental adhesive containing such a dendritic polymer, the curing rate of the lower alkyl (meth) acrylate is increased. Although the cause is not clear, the present inventors consider that it is based on the following principle. That is, the dendritic polymer has a gap between each branch of the three-dimensional branch structure, and in the powder liquid type dental adhesive, the (A) liquid material and (B) powder material are mixed. In the paste, the lower alkyl (meth) acrylate, which is a low molecular compound, enters the void together with the radical polymerization initiator. As described above, the polymerization activity of the lower alkyl (meth) acrylate is not high. However, since the molecules entering the inter-branch space are close to each other in a state in which the molecular movement is difficult, the lower alkyl (meta) is present in this portion. ) The polymerizability of the acrylate is increased, and it is presumed that the polymerization activity of the lower alkyl (meth) acrylate in the whole liquid material is increased from this. Thus, the curing speed of the lower alkyl (meth) acrylate is increased, and the dentist can quickly move on to the next treatment. Further, the mechanical strength of the cured body is increased, and the dentin or the prosthesis can be obtained. This further improves the adhesion.

  Examples of such dendritic polymers include dendrimers, linear-dendritic polymers, dendrigraft polymers, hyperbranched polymers, star hyperbranched polymers, hypergraft polymers, and the like. Among them, the first three types have a branching degree of 1 and have a defect-free structure, while the latter three types have a random branch structure that may contain defects.

  The branched structure of the dendrimer is formed by chemically reacting a monomer having a polyfunctional group step by step. Examples of the dendrimer synthesis method include a Divergent method for synthesis from the center to the outside and a Convergent method for synthesis from the outside to the center. Examples of dendrimers include amidoamine dendrimers (US Pat. No. 4,507,466 and others) and phenyl ether dendrimers (US Pat. No. 5,041,516 and others). As for the amidoamine dendrimer, a dendrimer having a terminal amino group and a carboxylic acid methyl ester group is commercially available as “Starburst ™ (PAMAM)” from Aldrich. Moreover, the amide amine type | system | group dendrimer with the corresponding terminal synthesize | combined by making the terminal amino group of the amide amine type | system | group dendrimer react with various acrylic acid derivatives and methacrylic acid derivatives can also be used.

  Various phenyl ether dendrimers are described in Journal of American Chemistry, Vol. 112 (1990, pages 7638-7647). As for the phenyl ether dendrimer, those obtained by substituting the terminals with various chemical structures can be used instead of the terminal benzyl ether bond.

  A hyperbranched polymer is a synthetic polymer generally obtained by a one-step polymerization method, unlike a dendrimer that forms a branched structure by precisely controlling a multi-step synthesis reaction. In order to synthesize a large molecule in one step, there are molecular weight distribution and insufficiently branched units. However, compared with the dendrimer, there are great advantages that production is easy and production cost is low. Moreover, if the synthesis conditions are appropriately selected, the degree of branching can be controlled, and molecular design according to the application can be performed. The hyperbranched polymer has, in one molecule, two or more first reaction points corresponding to a branched portion, and a single second reaction point corresponding to a connecting portion and different from the first reaction point. It is synthesized through a one-step synthesis process using monomers (Macromolecules, 29 (1996), 3831-3838).

  As such a synthesis process, for example, a self-condensation method of an ABx type monomer having two functional groups in one molecule, a vinyl group “A”, and a function capable of initiating polymerization with respect to the vinyl group “A”. Known are self-condensation vinyl polymerization of AC-type monomers having a group “C”, polycondensation of A2-type monomers and B3-type monomers (dendritic polymer-high functionality with multi-branched structure expanding) World, NTS Corporation (2005)). And a branched structure is formed at a stretch by these methods. In the description of the synthesis method described above, “A” and “B” shown in capital letters indicate different functional groups, and the Arabic numerals shown in combination with “A” and “B” are 1 indicates the number of functional groups in one molecule.

  Further, as a method for obtaining a hyperbranched polymer by polymerizing a compound having a functional group capable of initiating polymerization and a vinyl group in one molecule, a self-condensable vinyl polymerization method (SCVP method) is known (Science, 269, 1080 (1995)). In addition, as a method of synthesizing a hyperbranched polymer in which an initiator fragment is incorporated into a produced polymer by polymerizing a molecule having a plurality of polymerizable groups using a large amount of initiator, the initiator fragment-containing radical weight is synthesized. Legal (IFIRP) is known (J. Polymer. Sci .: Part A: Polym. Chem., 42, 3038 (2003)).

  The structure of the hyperbranched polymer has various structures depending on the chemical modification of the surface functional group of the ABx type monomer to be used or the obtained polymer. As the hyperbranched polymer, from the viewpoint of classification of the skeleton structure, hyperbranched polycarbonate, hyperbranched polyether, hyperbranched polyester, hyperbranched polyphenylene, hyperbranched polyamide, hyperbranched polyimide, hyperbranched polyamideimide, hyperbranched polysiloxane, Examples include hyperbranched polycarbosilane. In addition, as the end groups that these hyperbranched polymers have, alkyl groups, phenyl groups, heterocyclic groups, (meth) acryl groups, allyl groups, styryl groups, hydroxyl groups, amino groups, imino groups, carboxyl groups, halogeno groups, An epoxy group, a silyl group, etc. are mentioned. Further, these end groups can be further chemically modified to give functional groups according to the purpose to the hyperbranched polymer surface.

  In the powder type dental adhesive of the present invention, only one kind of these dendritic polymers may be used alone, or two or more kinds of dendritic polymers may be used in combination. Among the dendritic polymers listed above, dendritic polymers with a degree of branching represented by 1 such as dendrimers, linear-dendritic polymers, and dendrigraft polymers have a relatively dense structure with no defects. For this reason, voids between the branched branches in the dendritic polymer tend to be small, and the lower alkyl (meth) acrylate is not sufficiently penetrating into the voids. On the other hand, when the dendritic polymer has a random branch structure that may contain defects represented by a hyperbranched polymer, a star hyperbranched polymer, a hypergraft polymer, etc., The voids tend to be wide, and the lower alkyl (meth) acrylate is likely to enter the voids between the branched branches. For this reason, dendritic polymers with wide gaps between these branch branches can increase the polymerizability of powder-type dental adhesives, speed up the setting time, and adhere to teeth and prostheses. It is preferable because it increases. In particular, a hyperbranched polymer is preferable.

  Further, the molecular weight of the dendritic polymer is not particularly limited, but the weight average molecular weight measured by GPC (Gel Permeation Chromatography) method is preferably 1500 or more, more preferably 10,000 or more, Most preferably, it is 15000 or more. When the weight average molecular weight is not less than the above, a branched structure is formed and a space between each branched branch is widened. Therefore, the lower alkyl (meth) acrylate penetrates into the voids, and the effect of increasing the polymerization activity is exhibited more significantly, which is preferable. On the other hand, the upper limit of the weight average molecular weight of the dendritic polymer is not particularly limited, but is preferably 200000 or less, more preferably 100000 or less, and most preferably 80000 or less. When the weight average molecular weight is not more than the above, the dispersibility with respect to the lower alkyl (meth) acrylate is improved.

  When the molecular weight is within the above range, a spherical dendritic polymer having a hydrodynamic average diameter of about 1 nm to about 40 nm in tetrahydrofuran (THF) measured by a dynamic light scattering method can be obtained. The hydrodynamic average diameter is preferably in the range of 3 nm to 20 nm, and more preferably in the range of 5 nm to 15 nm.

  The blending amount of the dendritic polymer contained in the powder liquid type dental adhesive is not particularly limited. In the paste obtained by mixing the liquid material and the powder material, with respect to 100 parts by mass of the radical polymerizable monomer. 1 to 100 parts by mass, and more preferably 5 to 40 parts by mass. By setting the blending amount of the dendritic polymer particles to 1 part by mass or more, it becomes easier to reduce the polymerization shrinkage rate when curing the powder-type dental adhesive, and further, the effect of increasing the curing time. It becomes possible to make it exhibit more remarkably. In addition, when the blending amount of the dendritic polymer exceeds 100 parts by mass, the dendritic polymer is excessive and an excessive increase in viscosity is caused, so that adverse effects on operability and adhesiveness are increased. . Furthermore, the blending amount of the dendritic polymer is preferably 40 parts by mass or less because the adverse effects on the operability and adhesiveness can be extremely reduced.

  As the dendritic polymer used for the powder liquid type dental adhesive, the various dendritic polymers described above can be used, but at least one kind of branched portion selected from three branched portions and four branched portions. And a network structure (network-like multi-branch structure) including a connection part that connects the branched parts. A typical example of the dendritic polymer having such a network structure is a hyperbranched polymer. In addition, the more developed and formed the branch in the network structure, the movement of the molecular chains constituting the network structure is restricted, and the entanglement between the molecular chains is reduced. Even if it increases, the increase in a viscosity will be suppressed and it is more preferable. Furthermore, the space | gap between each branch branch of a dendritic polymer becomes wide, the hardening time of a powder-liquid type dental adhesive material can be made faster, and the adhesiveness to a tooth | gum or a prosthesis is also improved.

  In addition, the terminal portion of the network structure may have a reactive functional group with an ethylenically unsaturated group, or a reactive functional group such as an acidic group, an amino group, or a hydroxyl group. It may not have. In addition, when it has substantially no reactive functional group, the terminal part of network structure will be occupied by non-reactive functional groups, such as an alkyl group. Here, “substantially having no reactive functional group” means not only the case where there is no reactive functional group at the end of the network structure, but also the synthesis of a dendritic polymer having a network structure. It also means that a slightly reactive functional group is introduced into the end portion of the network structure due to occasional side reactions or impurities in the reaction system.

  When the terminal portion of the network structure has a reactive group with an ethylenically unsaturated group, the formation of a bond between the dendritic polymers or between the dendritic polymer and the radical polymerizable monomer results in It becomes easy to further improve the mechanical strength. Here, examples of the reactive group with the ethylenically unsaturated group include an ethylenically unsaturated group such as a styryl group, an acryloyl group, and a methacryloyl group, and a bidrosilyl group. Moreover, when the terminal part of network structure has a hydrophilic functional group, since the effect which becomes high to the adhesiveness to a tooth | gear is acquired, it is suitable. Here, examples of the hydrophilic functional group include an acidic group such as a carboxyl group and a phosphoric acid group, and a hydroxyl group, and a demineralizing function for a tooth is exhibited, so that the adhesiveness to the tooth is particularly high. Therefore, an acidic group is more preferable, and a phosphoric acid group is most preferable.

  In addition, the internal part of network structure may also have a reactive functional group. However, the reactive functional group located in the inner part of the network structure is less likely to react with other dendritic polymers or radically polymerizable monomers than the reactive functional group located at the terminal part. Considering the point that it is difficult to contribute to the improvement of the mechanical strength of the cured product, it is preferable that the internal part of the network structure has substantially no reactive functional group. The same applies to hydrophilic functional groups.

  In the network structure constituting the hyperbranched polymer, the number of branches is generally 3 or 4 branches. The three-branched branched portion (three-branched portion) is preferably formed of a nitrogen atom, a trivalent cyclic hydrocarbon group or a trivalent heterocyclic group, and the four-branched branched portion (four-branched portion) is: It is preferably formed of a carbon atom, a silicon atom, a tetravalent cyclic hydrocarbon group or a tetravalent heterocyclic group. The (trivalent or tetravalent) cyclic hydrocarbon group can be broadly classified as an aromatic hydrocarbon group exemplified by a (trivalent or tetravalent) benzene ring and the like, and (trivalent or tetravalent). And an alicyclic hydrocarbon group exemplified by a (cyclovalent) cyclohexane ring. As the (trivalent or tetravalent) heterocyclic group, a known heterocyclic group can be used. In addition, as a trivalent heterocyclic group, what is shown to following Structural formula 1 can also be mentioned, for example.

Moreover, it is preferable that the connection part which connects branch parts is any 1 type of bivalent group or atom selected from following Structural formula group X. Here, in Structural Formula Group X, R ¹¹ is an aromatic hydrocarbon group or an alkylene group having 40 or less carbon atoms, and n is an integer selected from the range of 1 to 9. Note that two or more of the plurality of connection portions coupled to one branch portion may be the same, or all the connection portions coupled to one branch portion may be different from each other.

  General examples of the terminal portion of such a network structure are selected from a hydrogen atom, a halogen atom (—F, —Cl, —Br, or —I), a styryl group, an epoxy group, a glycidyl group, and the following structural group Z And any one monovalent group, monovalent cyclic hydrocarbon group, or monovalent heterocyclic group. Here, the group excluding the hydrogen atom and the halogen atom in the terminal portion may be further chemically modified. In the monovalent cyclic hydrocarbon group and monovalent heterocyclic group, the hydrogen atom bonded to the ring may be substituted with a halogen atom, a carboxyl group, an amino group, a hydroxyl group, or a monovalent carboxylic acid ester. . In addition, the monovalent cyclic hydrocarbon group is roughly classified into an aromatic hydrocarbon group exemplified by a monovalent benzene ring and an alicyclic hydrocarbon group exemplified by a monovalent cyclohexane ring. Can be mentioned.

In Structural Formula Group Z, R ¹² is a monovalent aromatic hydrocarbon group or an alkyl group having 40 or less carbon atoms, and R ¹³ is a divalent aromatic hydrocarbon group or an alkylene having 40 or less carbon atoms. It is a group. Further, in the group represented by the structural formula group Z, when both R ¹² and R ¹³ are included, the structures of both may be the same or different from each other except for the valence.

  The terminal part of these network structures contains an ethylenically unsaturated group-containing group, a reactive group with an ethylenically unsaturated group such as a bidrosilyl group, an acidic group such as a carboxyl group or a phosphate group, or a hydroxyl group. This is particularly suitable as described above.

  Specific examples of the dendritic polymer that can be suitably used in the powder liquid type dental adhesive of the present invention include dendrites having a network structure formed by bonding unit structures represented by the following general formula (I) to each other. And the like polymer.

Here, in the general formula (I), A is a single bond linking the C and ^{R 1} (i.e., state and C and ^{R 1} is simply attached at bond σ),> C = O, -O —, —COO—, or —COO—CH ₂ —, wherein R ¹ is a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group, and R ² is a hydrogen atom Or Y is a group represented by the following general formula (IIa) or a group represented by the following general formula (IIb). When the network structure excluding the terminal portion is composed of the unit structure represented by the general formula (I), the unit structure represented by the general formula (I) constituting the network structure is substantially only one type. It may be comprised from two or more types.

  In the group represented by the following general formula (IIa) and the group represented by the following general formula (IIb), a is 0 or 1. Here, when Y is a group represented by the general formula (IIa), the unit structure represented by the general formula (I) is a unit structure having four bonds, and Y is represented by the general formula (IIb). In the case of the group shown, the unit structure has three bonds. Y is preferably a group represented by the general formula (IIa) from the viewpoint of easily suppressing an increase in viscosity when the blending ratio of the hyperbranched polymer to the powder liquid dental adhesive is increased.

  Examples of the terminal portion of the network structure formed by the unit structure represented by the general formula (I) include various atoms or various groups exemplified as general examples of the terminal portion described above.

R ¹ constituting the unit structure represented by the general formula (I) is a divalent saturated aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group. Here, the divalent saturated aliphatic hydrocarbon group may be either a chain or a ring. Moreover, although carbon number is not specifically limited, The inside of the range of 1-5 is preferable, and the inside of the range of 1-2 is more preferable. By setting the number of carbon atoms to 5 or less, the molecular chain portion shown as R ¹ is shortened, so that the entanglement between the radical polymerizable monomer constituting the liquid material and the hyperbranched polymer is further suppressed, and the paste An increase in viscosity can be further suppressed. Examples of the divalent chain saturated aliphatic hydrocarbon group include a methylene group, an ethylene group, a propylene group, and a butylene group. Examples of the divalent cyclic saturated aliphatic hydrocarbon group include a cyclopropylene group and a cyclobutylene group.

  In addition, the divalent aromatic hydrocarbon group includes a monocyclic ring containing one benzene ring, a monocyclic ring containing two or more benzene rings and having a condensed ring structure, or a condensed ring structure containing two or more benzene rings. Any of these may be used. The number of benzene rings contained in the divalent aromatic hydrocarbon group is not particularly limited, but is preferably in the range of 1 to 2, and the number of benzene rings is particularly preferably 1 (in other words, divalent aromatic The group hydrocarbon group is particularly preferably a phenylene group). Examples of the divalent aromatic hydrocarbon group include a naphthylene group and a biphenylene group in addition to the phenylene group described above.

It should be noted that, among the R ¹ exemplified above, especially a phenylene group is preferable. When using a phenylene group as R ^1, it is possible to improve the mechanical strength of the cured product of Konaeki type dental adhesive.

  At present, examples of hyperbranched polymers that can be suitably used as dendritic polymers, ie, commercially available hyperbranched polymers having the above-described structure, include “HYPERTECH” (registered trademark) series of Nissan Chemical Industries, Ltd., DSM “Hybrane” (registered trademark), “Boltorn” (registered trademark) manufactured by Perstop Co., etc. “HYPERTECH”, “Hybrane”, and “Bolton” are sold in different grades with different molecular weights, viscosities, and terminal groups.

  In the powder liquid type dental adhesive of the present invention, the dendritic polymer may be blended in any of (A) liquid material and (B) powder material, but has an affinity for lower alkyl (meth) acrylate. Therefore, it is particularly preferable to dissolve, swell, or finely disperse in a liquid material in advance because a uniform paste can be easily obtained when mixed with a powder material and the curing rate can be further increased.

  At least one of the powder type dental adhesive of the present invention also contains a radical polymerization initiator. The powder liquid dental adhesive is often cured by chemical polymerization, but a photopolymerization initiator may be blended instead of the chemical polymerization initiator and cured by photopolymerization.

  As the chemical polymerization initiator, a redox type polymerization initiator composed of an organic peroxide / amine compound or an organic peroxide / amine compound / sulfinate; an organic metal type polymerization that starts polymerization by reacting with an acid An initiator; a polymerization initiator composed of an organic boron compound or a partial oxide of an organoboron compound; and a polymerization initiator composed of (thio) barbituric acid derivative / cupric ion / halogen compound can be used. As a specific example of such a polymerization initiator, for example, those exemplified in Japanese Patent Application No. 2000-361150 can be used.

  In particular, as the organometallic polymerization initiator, tributylborane, a partial oxide of tributylborane, or an aryl borate salt exemplified by the general formula (1) described later is preferably used from the viewpoint of aesthetics and the like. At this time, conventionally known organic acids and inorganic acids can be used as the acid combined with the aryl borate salt. Strong acids are preferred because of their high reactivity, and sulfonic acid group-containing compounds are particularly easy to handle. For such an acid, a polymerizable monomer containing an acidic group may be used as a part of the liquid material (A). Moreover, considering the storage stability of the liquid material (A), an acidic compound that is solid at room temperature, such as 2-methacrylamide-2-methylpropanesulfonic acid, is included as part of the powder material (B) described above. Also good.

  The aryl borate salt is not particularly limited as long as it is a tetracoordinate boron compound having at least one boron-aryl bond in the molecule, and a known compound can be used. A borate compound having no boron-aryl bond is extremely unstable and is practically impossible to use because it easily decomposes by reacting with oxygen in the air.

  The aryl borate salt used in the present invention is represented by the following general formula (1) from the viewpoint of storage stability and polymerization activity.

(In the above formula, R ^a , R ^b and R ^c are each independently an alkyl group, an aryl group or an alkenyl group, and these groups each may have a substituent; R ^d and R each ^e is independently a hydrogen atom, a halogen atom, a nitro group, an optionally substituted alkyl or alkoxy group, or an optionally substituted phenyl group; L ⁺ is a metal cation , A tertiary or quaternary ammonium ion, a quaternary pyridinium ion, a quaternary quinolinium ion, or a quaternary phosphonium ion.).

  Among these, an aryl borate salt in which a boron atom is substituted with four aryl groups is particularly preferable from the viewpoint of storage stability and availability.

  On the other hand, as photopolymerization initiators, diacetyl, acetylbenzoyl, benzyl, 2,3-pentadione, 2,3-octadione, 4,4′-dimethoxybenzyl, 4,4′-oxybenzyl, camphorquinone, 9,10 -Α-diketones such as phenanthrenequinone and acenaphthenequinone, benzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin propyl ether, 2,4-diethoxythioxanthone, 2-chlorothioxanthone Thioxanthone derivatives such as methylthioxanthone, benzophenone, benzophenone derivatives such as p, p′-dimethylaminobenzophenone, p, p′-methoxybenzophenone, acylphosphine oxide derivatives, and aryl borate compounds / dyes / photoacids It includes a system consisting of the raw material. These may be added alone or in combination as necessary.

  In addition, α-diketones and acylphosphine oxides are used in combination with amine compounds such as ethyl 4-dimethylaminobenzoate, lauryl 4-dimethylaminobenzoate, and dimethylaminoethyl (meth) acrylate to obtain higher activity. May be. However, since the amine compound causes coloring of the cured product, it is preferably suppressed to 0.5% by weight or less with respect to 100% by weight of the polymerizable monomer.

  Among these photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators are particularly preferred because particularly high photopolymerization activity can be obtained. The acyl phosphine oxide polymerization initiator is not particularly limited as long as it is a compound having a skeleton in which at least one acyl group {—C (═O) —} is bonded to a> P (═O) — group. A phosphine oxide derivative and a bisacylphosphine oxide derivative are used without any limitation. For example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphine Acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5- Dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,4,4-tri Tylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- ( 2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis- (2,5,6-trimethylbenzoyl) -2,4,4-trimethylpentylphosphine oxide are raised. Among these acylphosphine oxide polymerization initiators, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, because of its high activity, Bis- (2,4,6-trimethylbenzoyl) phenylphosphine oxide is preferred.

  The blending amount of the radical polymerization initiator in the powder liquid type dental adhesive of the present invention is not particularly limited as long as it is an amount sufficient to polymerize the lower alkyl (meth) acrylate contained in the liquid material (A), From the viewpoint of various physical properties such as weather resistance of the cured product, it is preferably in the range of 0.01 to 20 parts by mass with respect to 100 parts by mass of (A) the lower alkyl (meth) acrylate. It is especially preferable that it is 0.1-10 mass parts.

  When the radical polymerization initiator is composed of a plurality of components, the polymerization reaction of the radical polymerizable monomer contained in the liquid material (A) is not started during storage, and the radical polymerization initiator is stabilized. In consideration of the properties, it is preferable to mix these components separately for each of (A) liquid material and (B) powder material. In some cases, the radical polymerization initiator may be packaged separately from (A) the liquid material and (B) the powder material.

  Furthermore, it may be a dual cure type by combining a chemical polymerization initiator and a photopolymerization initiator. When the dual cure type is used, the mechanical strength of the cured body is particularly high. In addition, if the rough polymerization is allowed to proceed in a short time by light irradiation, and then the polymerization is completed with a chemical polymerization initiator, the curing time will be significantly greater than when only a conventional chemical polymerization initiator is used. This is particularly preferable because it can be shortened and the operability and mechanical strength can be made highly compatible.

  The powder liquid type dental adhesive of the present invention may be used by applying a paste or resin mud obtained by mixing (A) liquid material and (B) powder material to the tooth surface. If the material surface is pretreated with a dental pretreatment material in advance, it is preferable because higher adhesive force can be obtained. That is, it is good also as a dental adhesive kit containing (a) the said powder liquid type dental adhesive and (b) the dental pretreatment material which consists of the aqueous solution of an acidic compound.

  Here, examples of the dental pretreatment material include an etching treatment material and a primer. Examples of the etching treatment material include aqueous solutions (acid aqueous solutions) such as phosphoric acid, carboxylic acid, and citric acid. On the other hand, examples of the primer include a composition containing an acidic group-containing radical polymerizable monomer and water. In any case, the concentration of the acidic compound is preferably 1% by mass or more, preferably 3 to 90% by mass. As such dental pretreatment materials, JP-A-2008-222642, JP-A-07-118116, JP-A-08-310912, JP-A-08-319209, JP-A-09-025208 are disclosed. JP-A 09-227325, JP-A 10-251115, JP-A 2002-265212, JP-A 2003-096122, JP-A 2004-043427, JP-A 2004-026838, etc. Those described can be appropriately selected and used.

  The powder liquid type dental adhesive of the present invention may be used in a method (referred to as a mixing method) used after mixing (A) liquid material and (B) powder material with a spatula to form a paste, (A) Liquid material and (B) powder material are prepared separately, the liquid material is contained in the small brush, and then the ball tip is brought into contact with the powder material to produce a ball-shaped resin mud on the brush tip. It may be used by a method (referred to as brush writing method). In these methods of use, the mixing ratio of the (A) liquid material and the (B) powder material is usually 1: 3 to 5: 1 by mass ratio.

  When the powder liquid type dental adhesive is a dual cure type, the time until the paste or resin mud is irradiated with light is not particularly limited, but after the mixing of (A) liquid material and (B) powder material is started. It is appropriate to start the light irradiation in about 10 to 120 seconds. The light irradiation time is usually 3 to 90 seconds, preferably 3 to 50 seconds. As a light source, a xenon lamp, a halogen lamp, a metal hydride lamp, a tungsten lamp, a fluorescent lamp, an argon lamp can be used as long as it emits light having a wavelength effective for photolysis of the photopolymerization initiator, that is, a wavelength in the range of 250 to 500 nm. A laser or the like can be used without limitation.

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

  The compounds used in Examples and Comparative Examples and their abbreviations are (1), the properties of dendritic polymers are (2), the properties of non-crosslinked poly lower alkyl (meth) acrylate particles are (3), dental The primer composition for use is shown in (4), and the evaluation method for the powder-type dental adhesive is shown in (5).

(1) Compound used and its abbreviation MMA; methyl methacrylate PM; mixture of 2-methacryloyloxyethyl dihydrogen phosphate and bis (2-methacryloyloxyethyl) hydrogen phosphate TMPT; trimethylolpropane trimethacrylate HEMA; 2-hydroxy Ethyl methacrylate UDMA; 1,6-bis (methacrylethyloxycarbonylamino) 2,2,4-trimethylhexane and 1,6-bis (methacrylethyloxycarbonylamino) 2,4,4-trimethylhexane mixture PhBTEOA; tetra Phenylboron triethanolamine salt MMPS; 2-methacrylamide-2-methylpropanesulfonic acid BTPO; bis (2,4,6-trimethylbenzoyl) -phenylphosphine Kisaido DMEM; N, N-dimethylaminoethyl methacrylate BMOV; bis (Marutorato) oxovanadium (IV)
BHT; dibutylhydroxytoluene CQ; camphorquinone DMBE; ethyl pN, N-dimethylaminobenzoate (2) Dendritic polymer HPS-200; Nissan Chemical Industries, Ltd., weight average molecular weight 23000 by GPC method, fluid dynamics Hyperbranched polymer with a mean average diameter of 7.5 nm. The terminal functional group is a styryl group.
HA-DVB-500; Nissan Chemical Industries, Ltd. Hyperbranched polymer having a weight average molecular weight of 48000 by GPC method and a hydrodynamic average diameter of 11.7 nm (in THF). The functional group (terminal functional group) located at the terminal portion of the dendritic polymer is a methyl ester group.
HA-DMA-200; Nissan Chemical Industries, Ltd., hyperbranched polymer having a weight average molecular weight of 22000 by GPC method and a hydrodynamic average diameter of 5.2 nm (in THF). The terminal functional group is a methyl ester group.
PBP: Perton's Boltorn H40 (a polycondensate of dimethylolpropane having trimethylolpropane as a core, weight average molecular weight 2100 by GPC method), which is a hyperbranched polymer having a hydroxyl group as a terminal functional group. A hyperbranched polymer in which a part of the hydroxyl group as a terminal functional group is changed to a phosphate group by contacting at ° C. The adjustment method and the structural analysis were performed in the same manner as in Example 1 of JP-A-2006-160789. The ratio of the terminal functional group is hydroxyl group / phosphate group = 1/1.

(3) Non-crosslinked poly lower alkyl (meth) acrylate particles [Polymethyl methacrylate particles (P1 to P4), copolymer particles of methyl methacrylate and ethyl methacrylate (P5)] shown in Table 1 were used. The average particle diameter of the particles is the median diameter measured by the laser diffraction / scattering method, the specific surface area is the BET specific surface area value (m ² / g) by the nitrogen adsorption method, and the weight average molecular weight is gel permeation It is the value measured as a molecular weight in terms of polystyrene using an association chromatography.

  In addition, the irregular shaped particles are obtained by superheated spherical particles synthesized by suspension polymerization at 90 to 120 ° C. to such an extent that they can be crushed or crushed. , Pot; 300 mL alumina pot) was used, and 100 g of fused particles and 100 g of φ10 mm alumina balls were mixed and crushed and pulverized until the desired specific surface area was obtained. .

(4) Dental primer composition 20 wt% PM, 30 wt% water, 41 wt% acetone, 7 wt% UDMA, 2 wt% DMEM, 0.2 wt% BMOV and 0.3 wt% Of BHT.

(5) Evaluation method of powder liquid type dental adhesive <Evaluation method of curing time>
For the evaluation of chemical curing, prepare a wax sheet mold with a hole of 6 mmφ × 2 mm thickness into which a thermocouple with an aluminum foil wound at the tip is prepared, and each dental adhesive material of the present invention and comparative examples The powder material and the liquid material are mixed for 10 seconds with a powder / liquid (mass ratio) of 2, and the resin mud thus obtained is poured into the hole, and the opening of the hole of the wax sheet is covered with a PP sheet. did. One minute after the start of mixing, the mold containing the resin mud was immersed in a constant temperature water bath at 37 ° C., and the time from the start of mixing to the maximum exothermic point was measured as the curing time.

  When evaluating photocuring, at 23 ° C, a powder material and a liquid material are separately collected in a dappen dish, and the brush tip has a root diameter of about 2 mm and a liquid absorption amount of about 10 to 15 mg (Tokuyama brush) Using a disposable brush for stacking N (manufactured by Tokuyama Dental Co., Ltd.), a ball of resin mud (powder / liquid (mass ratio is approximately 2)) is prepared at the tip of the brush by a brushing method. After 30 seconds from the start of writing, light is irradiated with a dental visible light irradiator (Tokuso Power Light, manufactured by Tokuyama Co., Ltd.), and when a 50 g load is applied, the needle (φ : 0.5 mm) was evaluated whether it would not enter the cured body. When evaluating chemical curing, it was evaluated how many seconds from the start of writing a stroke a needle (φ: 0.5 mm) applied with a load of 50 g would not enter the cured body.

<Measurement method of enamel bond strength>
Within 24 hours after slaughter, the front teeth of the cow were removed, and the enamel plane was cut out with water-resistant abrasive paper # 600 so that it was parallel to the lip surface under water injection. Next, compressed air was blown onto these surfaces for about 10 seconds to dry them, and then a double-sided tape with a hole having a diameter of 3 mm was fixed on this surface to define the area of the adherend surface. The dental primer was applied to the holes, allowed to stand for 20 seconds, and then compressed air was blown for about 10 seconds. A dental primer having the following composition was used.

  After the application of the dental primer, a wax sheet with a hole having a thickness of 0.6 mm and a diameter of 8 mm was fixed on the circular hole so as to have the same center. Then, using the powder material and the liquid material of the powder liquid type dental adhesive material of Example or Comparative Example, resin mud by the brushing method using Tokuyama brush stacking disposable brush N (manufactured by Tokuyama Dental Co., Ltd.) [Powder / Liquid (mass ratio) is approximately 2]. The obtained resin mud was transferred into the above-mentioned wax sheet hole, and the hole was filled with the resin mud without excess or deficiency. Immediately after that, the polypropylene sheet was put on the opening of the hole of the wax sheet and the lid was closed (in this case, the polypropylene sheet was not pressed and the non-pressure welding method was used), and immediately a constant temperature and humidity box at 37 ° C. and humidity of 100%. And allowed to react for 1 hour to cure.

  After 1 hour, the polypropylene sheet and wax sheet were removed. In the cured body obtained by curing the resin mud, a circular plane having a diameter of 8 mm corresponding to the opening plane of the wax sheet (the contact plane between the resin mud and the polypropylene sheet) is formed horizontally with the adherend surface. In addition, using Tokuyama Multibond II (manufactured by Tokuyama Dental Co., Ltd.), which is a resin cement for dental bonding, on the flat surface of the cured body, a stainless steel attachment having a diameter of 8 mmφ was adhered to prepare an adhesion test piece.

After the said adhesion test piece was immersed in 37 degreeC water for 24 hours, the tensile bond strength with a tooth | gear was measured with the crosshead speed of 1 mm / min using the tension tester (autograph, Shimadzu Corporation make). The five tensile bond strengths per test were measured by the above method, and the average value was defined as the bond strength.

Examples 1-8, Comparative Examples 1-3
A liquid material having the composition shown in Table 2 was prepared. On the other hand, a mixed powder composed of 98% by mass of P1 and 2% by mass of MMPS was prepared as a powder material. With respect to the powder type dental adhesives in which the respective liquid materials and powder materials were combined, the curing time and the enamel bond strength were evaluated according to the above (5). The respective evaluation results are shown in Table 2.

  As in Examples 1 to 7, the powder type dental adhesive of the present invention reached curing in a short time (240 seconds or less). In the case where the dendritic polymer content was large as in Examples 1 and 2, the enamel bond strength was high. Further, in Example 8 where the content of the dendritic polymer is large (containing 50% by mass of the dendritic polymer in the liquid material), curing was achieved in a short time. However, the familiarity between the liquid material and the powder material was slightly poor, and the enamel bond strength was slightly lower than the others.

  On the other hand, Comparative Example 1 is a result of evaluating the composition without the dendritic polymer, but it took 290 seconds until the final curing in the chemical polymerization.

  Further, as in Comparative Example 2 and Comparative Example 3, in the case where the liquid material used was a polyfunctional radical polymerizable monomer as the main component, the curing time could be slightly shortened, but the dendritic polymer was It did not reach the composition.

Examples 9-14
As liquid materials, 75.5 wt% MMA, 20 wt% HPS-200, 5 wt% HEMA, 3 wt% PhBTEOA, 3.5 wt% CQ, 1 wt% DMBE and 0.1 wt% A composition consisting of% BHT was prepared. On the other hand, a powder material having the composition shown in Table 3 was prepared. With respect to the powder type dental adhesive in which the liquid material and each powder material were combined, the curing time and the enamel bond strength were evaluated according to (5). The respective evaluation results are shown in Table 3.

  Examples 9-12 showed high adhesive strength and the curing time was also short. Moreover, although Example 13 is a result of using the thing with a small specific surface area of a powder material, hardening time became a little long. Further, in Example 14 in which the powder material having a larger total specific surface area was used, the familiarity between the powder material and the liquid material was deteriorated, and the enamel bond strength was slightly low.

Claims (8)

(A) A liquid material containing lower alkyl (meth) acrylate as a main component, and (B) non-crosslinked poly lower alkyl (meth) acrylate particles having a volume average particle diameter of 0.1 to 150 μm as a main component. In a powder-liquid type dental adhesive comprising a combination of a powder material containing, and a radical polymerization initiator blended in at least one of the (A) liquid material and (B) powder material,
Further, the (A) liquid medium and (B) Ri to at least one of the powdery material name is blended is dendritic polymers, the amount of dendritic polymer contained in Konaeki dental adhesive comprises a liquid material in the paste obtained by mixing the powder material, 11 to 91 parts by mass der Ru powder-liquid type dental adhesive of the radical polymerizable monomer 100 parts by mass. (B) The powder-liquid type dental adhesive according to claim 1, wherein the non-crosslinked poly-lower alkyl (meth) acrylate particles contained in the powder material have a specific surface area of 0.7 to 5.5 m2 / g. The powder-liquid dental adhesive according to claim 1 or 2, wherein the dendritic polymer has a weight average molecular weight of 1500 to 200,000. The powder liquid type dental adhesive according to any one of claims 1 to 3, wherein the dendritic polymer is a hyperbranched polymer. The dendritic polymer has a network structure including at least one kind of branch part selected from a branched part having three branches and a branched part having four branches, and a connecting part connecting the branched parts. The powder-liquid type dental adhesive as described in any one of 1-4. The powder-liquid type dental adhesive according to claim 5, wherein a dendritic polymer having a reactive group with an ethylenically unsaturated group is used at a terminal portion of the network structure. The powder-liquid type dental adhesive according to claim 5, wherein a dendritic polymer having a hydrophilic functional group at a terminal portion of the network structure is used. (A) the powder type dental adhesive according to claims 1 to 7;
(B) A dental adhesion kit comprising a dental pretreatment material comprising an aqueous solution of an acidic compound.