JPH10182329A - Dental polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pasty dental polymer composition capable of giving a cured body having stable mechanical properties for a long time, scarcely eluting the unpolymerized monomer in the oral cavity and excellent in staining resistance and enabling the impressing operation in the oral cavity. SOLUTION: This dental polymer composition is composed of (a) a thermoplastic elastomer containing (A) one or more thermoplastic polymer blocks consisting of an aromatic vinyl monomer and having a number average molecular weight of >=3000 and (B) one or more elastomer polymer blocks and (b) a (meth)acrylate monomer and (c) an acylphosphine oxide as a polymerization initiator and has consistency of 13-40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a dental polymerizable composition. More specifically, the present invention relates to a dental polymerizable composition having a paste property that allows an impression operation in the oral cavity.
The composition of the present invention can be used as a material for dental wearing articles such as denture bases, orthodontic bases, temporary crowns, etc., which involve an impression operation in the oral cavity or on a plaster model.

[0002]

2. Description of the Related Art At present, in dental treatment, a denture base made of a polymerizable resin composition for a floor (hereinafter sometimes referred to as resin) is worn on a patient who has lost teeth due to age or the like. . In general, the denture base wearer remarkably absorbs the ridges, thins the mucous membrane that is responsible for cushioning, and collapses the alveolar bone due to bone resorption. It has been pointed out that compatibility with the oral cavity is reduced.

When the compatibility between the denture base and the oral cavity is reduced,
In general, a denture base mucosal surface called rebase (reformation) is reformed to restore compatibility with the oral cavity. Rebase methods can be broadly divided into two types: indirect methods and direct methods. The indirect method is a method of taking an impression of the shape of the oral cavity using an impression material, reproducing the oral model with the same shape as the oral cavity in the laboratory, and using the model to form the mucosal surface of the old denture base It is. On the other hand, in the direct method, a rebase material is laid on the mucosal surface of the denture base, the impression operation is performed in the oral cavity in the same way as the usual impression acquisition, and curing is performed while maintaining the shape of the obtained impression Is a method of performing rebasing. As described above, the indirect method is performed in a laboratory and requires many steps, so that it takes a considerable period of time to perform rebase. Cause trouble. In addition, since many impression operations are required during rebasing, errors during impression are likely to occur, and the possibility of lowering compatibility with the oral cavity is higher than in the direct method. For these reasons, the direct law is widely accepted at present.

[0004] The rebase material is generally made of a hard material having the same hardness as the denture base resin. However, when there is bite pain due to thinning of the oral mucosa,
Even if the compatibility with the oral cavity is restored, pain may still remain, and a soft material having appropriate viscoelasticity is often used in order to provide cushioning properties in place of mucous membranes. Conventionally, as a soft rebase material by a direct method, a soft resin in which a plasticizer is blended with an acrylic resin, a silicone resin-based lining material, and the like have been used [Kusakari et al., “Tooth World Outlook,” Vol. 72, No. 6, No. (1988), 1267-
1272]. These soft rebase materials are composed of a powder and a liquid, or two pastes, and are prepared so as to be hardened by kneading them immediately before use.

On the other hand, Japanese Patent Application Laid-Open No. 52-503 discloses that
(A) styrene-butadiene block copolymer,
(B) a liquid prepolymer of polybutadiene or a butadiene-styrene copolymer, (c) a photopolymerizable monomer,
A photosensitive resin composition for flexographic printing plates comprising (d) a photopolymerization initiator and (e) a thermal polymerization inhibitor optionally added is disclosed. From this composition, a molded article having rubber elasticity is obtained.

[0006]

By the way, it has been pointed out that the above-mentioned soft rebase material has a problem in that when it is inserted into the oral cavity, it is stimulated by the monomer of the raw material or stimulated by heat generated during curing. In addition, the cured product obtained from these soft rebase materials contains many air bubbles and has a high water absorption rate. However, there is also a problem that the bacterium is strongly contaminated by oral bacteria and has a strong odor.
Also, by looking at the material, in the case of a soft resin in which a plasticizer is blended with an acrylic resin, the plasticizer elutes in the oral cavity, the resin itself gradually hardens, and moisture and food residues remain in the eluted voids.
The problem is that bacteria and the like enter into the container and the contamination resistance is reduced. In addition, the silicone-based rebase material is problematic in that it is easily stained in the oral cavity due to the properties of the material itself, and is easily adhered to the denture base and easily peeled off when worn. Furthermore, denture stabilizers and tissue conditioners that have been used frequently in recent years lack stability in the oral cavity and are decomposed or hardened, so that they are limited to temporary use.

On the other hand, in the composition disclosed in Japanese Patent Application Laid-Open No. 52-503, a liquid prepolymer of polybutadiene or a butadiene-styrene copolymer enhances the adhesiveness to the oral mucosa and makes the impression operation difficult. To

The present invention has been made in view of the above prior art, and has a paste property suitable for performing an impression operation in the oral cavity, and has a suitable viscoelasticity stable in the oral cavity for a long period of time. It is an object of the present invention to provide a dental polymerizable composition which provides a cured product which is maintained in a stable manner, suppresses the dissolution of unpolymerized monomers, and prevents intrusion of contaminants such as food residues and bacteria.

[0009]

The above object is achieved by (a) the aromatic vinyl monomer having a number average molecular weight of 3,000.
A thermoplastic elastomer having at least one thermoplastic polymer block (A) and at least one elastomer polymer block (B), (b) a (meth) acrylate monomer, and (c) an acylphosphine oxide as a polymerization initiator And having a consistency of from 13 to 40.

The thermoplastic elastomer (a) used in the present invention comprises a thermoplastic polymer block (A) comprising an aromatic vinyl monomer and an elastomer polymer block (B).
And containing. One block (A) and one block (B) may be present in the thermoplastic elastomer (a), but a plurality of blocks may be present respectively.

The thermoplastic polymer block (A), which is a component of the thermoplastic elastomer (a), comprises aromatic vinyl monomer units and has a number average molecular weight of 3,000 or more. Examples of the aromatic vinyl monomer unit include styrene, 1-vinylnaphthalene, 2-vinylnaphthalene,
Examples include 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4- (phenylbutyl) styrene and the like. Of these, styrene is preferred. There is no particular limitation on the bonding manner of these monomer units, and a structure in which one of these monomer units is polymerized alone or a structure in which two or more monomer units are copolymerized may be used. .

The number average molecular weight of the thermoplastic polymer block (A) of the aromatic vinyl monomer unit needs to be 3,000 or more, and 3,000 to 1,000,000.
00 is preferred. The number average molecular weight of the block A is 3,0
If it is less than 00, a paste having excellent impression cannot be obtained.

[0013] The content of the thermoplastic polymer block (A) in the thermoplastic elastomer (a) is preferably in the range of 5 to 70% by weight. More preferably, 5 to 30
% By weight. When the content of the thermoplastic polymer block (A) is 5 to 70% by weight, the compatibility with the (meth) acrylate-based monomer (b) described later is good, and a paste having desired properties can be obtained.

The elastomer polymer block (B) in the thermoplastic elastomer (a) is composed of monomer units constituting a known thermoplastic elastomer. The bonding manner of the monomer units is not particularly limited, and may be a structure in which one of the monomer units is polymerized alone, or a structure in which two or more monomer units are copolymerized.

[0015] Among them, a thermoplastic elastomer polymer composed of at least one monomer unit selected from isoprene, isobutylene, butadiene and butyl acrylate, a hydrogenated product of the polymer, and an unsaturated carboxylic acid or Adducts of the acid derivatives are preferred. The block (B) composed of these polymers is
One of the above-mentioned elastomer polymer, its hydrogenated product and its adduct may be used as a component, or a plurality of the above may be used as a component.

Further, as the block (B), a thermoplastic elastomer polymer composed of at least one selected from polyisoprene and isoprene-butadiene copolymer and having a vinyl bond content of 40 mol% or more;
Also preferred are hydrogenated products of the polymer and adducts of unsaturated carboxylic acids or derivatives of the acid in the polymer. Similarly to the above, these may be composed of one of the elastomer polymer, its hydrogenated product and its adduct, or may be composed of plural components. Here, the vinyl bond content refers to an ethylenic double bond in a side chain generated by the following bonding mode among all carbon-carbon double bonds contained in an elastomer polymer block of polyisoprene or isoprene-butadiene. (Mol%).

The unsaturated carboxylic acid and its derivative to be added to the thermoplastic elastomer polymer include maleic anhydride, maleic acid, fumaric acid, acrylic acid, itaconic acid, crotonic acid and the like.

The elastomeric polymer block (B) containing isoprene and butadiene monomers forms a 1,2 bond or a 3,4 bond depending on the polymerization mode to form an ethylenic double bond in a side chain. This ethylenic double bond is 1,
Compared with the double bond of the main chain formed by four bonds, it has high reactivity and can be copolymerized with the (meth) acrylate monomer (b). Therefore, the elastomer (a) having the polymer block having the bond gives a paste having excellent polymerization curability, and the polymer cured product has a small permanent set due to chemical cross-linking, and thus is suitable.

The content of the elastomer polymer block (B) in the thermoplastic elastomer (a) is preferably in the range of 30 to 95% by weight, more preferably 70 to 95% by weight.

Examples of the thermoplastic elastomer (a) include diblocks, triblocks, multiblocks, star-shapes having a polystyrene block, and taper-types in which the boundaries between blocks are gradually changed by random copolymerization. Styrene-isoprene-based elastomer, styrene-butadiene-based elastomer which is a thermoplastic elastomer containing a polystyrene-based block copolymer,
Styrene-isoprene-butadiene-based elastomer, styrene-isobutylene-based elastomer, styrene-butyl acrylate-based elastomer and the like can be mentioned.

Among these, Japanese Patent Application Laid-Open No. 2-102212
Thermoplastic elastomers disclosed in
In the molecule, two or more blocks of an aromatic vinyl monomer having a number average molecular weight of 3,000 or more and 40,000 or less and one block of isoprene and / or isoprene-butadiene having a vinyl bond content of 40 mol% or more are included. And the molecular weight is 40,000 or more and 300,0 or more.
The block copolymer of not more than 00 has, in addition to the above properties,
Since the polymer cured product of the present invention is fitted in the mouth and bites, it is particularly suitable because it has excellent vibration damping performance.

A paste containing an elastomer generally tends to recover from creep. This phenomenon indicates that when taken out after performing an impression in the oral cavity, it is easy to return to the pre-impression form over time, indicating that it is not suitable for impression. However, by having a thermoplastic elastomer block composed of an aromatic vinyl monomer, creep recovery is unlikely to occur, and a composition having excellent impression can be obtained.

The rubber hardness of the thermoplastic elastomer (a) is not particularly limited, but is preferably in the range of 30 to 90. Here, the rubber hardness refers to JIS K 62
This is a value measured using a durometer type A according to No. 53.

As the (meth) acrylate monomer (b), either a monofunctional (meth) acrylate or a polyfunctional (meth) acrylate can be used. As the monofunctional (meth) acrylate, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate,
Hexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate and stearyl (meth) acrylate such as alkyl (meth) acrylate (alkyl group having 1 to 20 carbon atoms), methoxyethyl ( Meth) acrylate, 2-phenoxyethyl (meth) acrylate,
Methoxy polyethylene glycol (meth) acrylate (degree of polymerization 2 to 10), tetrahydrofurfuryl (meth)
Examples include acrylate, isobornyl (meth) acrylate, undecenyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate (HEMA), and dimethylaminoethyl (meth) acrylate.

Examples of the polyfunctional (meth) acrylate include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and neopentyl glycol. Di (meth) acrylate,
Alkylene glycol di (meth) acrylate (alkylene group having 1 to 20 carbon atoms) such as 1,6-hexanediol di (meth) acrylate and 1,10-decanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, Polyalkylene glycol di (meth) acrylates such as triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate and polyethylene glycol di (meth) acrylate (where the alkylene group has 2 to 4 carbon atoms;
And a polymerization degree of 2 to 200), glycerin di (meth) acrylate, 2,2′-bis [p- (γ-methacryloxy-
β-hydroxypropoxy) phenyl] propane (Bi
s-GMA), bisphenol A dimethacrylate,
2,2′-bis (4-methacryloxypolyethoxyphenyl) propane (2 to 10 ethoxy groups per molecule),
Examples thereof include 1,2-bis (3-methacryloxy-2-hydroxypropoxy) butane, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and urethane (meth) acrylate. These (meth) acrylate monomers are used alone or in combination of two or more.

Among these, the alkyl (meth) acrylate and the alkylene glycol di (meth) acrylate are the thermoplastic elastomers (a) used in the present invention.
It is particularly high in compatibility with and is suitable. It is desirable that these alkyl (meth) acrylates or alkylene glycol di (meth) acrylates are contained in the (meth) acrylate-based monomer (b) in an amount of 40% by weight or more.

As the (meth) acrylate monomer (b), n-hexyl (meth) acrylate, n
When a monofunctional (meth) acrylate having an alkyl group or an alkenyl group having a large number of carbon atoms (6 or more carbon atoms) such as lauryl (meth) acrylate or n-stearyl (meth) acrylate is mainly used, a soft cured product is obtained. Is obtained. On the other hand, as the (meth) acrylate-based monomer (b), methyl (meth) acrylate, n-butyl (meth)
When a monofunctional (meth) acrylate or polyfunctional (meth) acrylate having an alkyl group or an alkenyl group having a small number of carbon atoms such as acrylate is mainly used, a relatively hard cured product tends to be obtained.

Examples of the polymerization initiator (c) in the present invention include acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and diethoxyphosphine oxide which are photopolymerization initiators. By using the acylphosphine oxide, the polymerization rate of the (meth) acrylate monomer is improved, and the amount of the unpolymerized monomer is reduced. By reducing the amount of unpolymerized monomer, the amount of elution into the oral cavity can be suppressed, the risk of developing allergies due to the monomer is reduced, and the stain resistance is improved. In addition, there is no change in color tone even when the present polymerization catalyst is added to the composition, and the composition is excellent in aesthetics, and there is no odor or irritation even when it is worn in the oral cavity. Furthermore, the storage stability is extremely high, and there is no possibility of polymerization and curing during storage or deterioration of photopolymerization curability due to deterioration. Other photopolymerization initiators can be used in combination with the acylphosphine oxide. Examples of the photopolymerization initiator include camphorquinone, diacetyl, 2,3-pentanedione,
Α-diketones such as benzyl, acenaphthenequinone and phenanthraquinone, benzoin methyl ether, benzyldimethyl ketal, benzophenone, 2-ethylthioxanthone and the like. These photopolymerization initiators are used as a polymerization initiator system appropriately combined with a polymerization initiator.

As such a polymerization initiation auxiliary, for example,
N, N-dimethylaminoethyl methacrylate, N, N
-Ethyl-dimethylaminobenzoate, bis-N, N-dimethylaminobenzophenone, N, N-dimethylaminobenzaldehyde, N-phenylglycine, morpholinomethacrylate, triethanolamine, N-methyldiethanolamine, N, N-dimethylaminobenzoic acid 2-
Tertiary amines such as n-butoxyethyl and isoamyl N, N-dimethylaminobenzoate can be mentioned, and for example, citronellal, lauryl aldehyde, o
Aldehydes such as -phthaldialdehyde and p-octyloxybenzaldehyde. Further examples include mercaptans such as 1-decanethiol, thiosalicylic acid, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 4-mercaptoacetophenone, and 4-t-butylthiophenol. .

Further, azo compounds such as benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, azobisisobutyronitrile, and thiuram compounds such as tetramethylthiuram disulfide may be used as the photopolymerization initiator. A system to which a compound is added is also included. Among them, a system in which camphorquinone and a reducing agent are combined with an acylphosphine oxide is suitable in that, in addition to reducing unpolymerized monomers, the thickness of polymerization and curing in the vertical direction of light irradiation can be improved. . A relatively small amount of camphorquinone and a reducing agent to be added at this time are sufficient, and the odor and color tone are not significantly impaired. Among the reducing agents used herein, N, N-dimethylaminoethyl methacrylate, N, N-dimethylaminobenzophenone, N, N-dimethylaminobenzoic acid 2
-N-Butoxyethyl is preferred.

When the polymerization initiator contains the above-mentioned polymerization initiation auxiliary agent, both components react depending on the combination of the auxiliary agents, for example, an organic peroxide and a tertiary amine. From the viewpoint of properties, it is necessary to form a separate package so that the polymerization initiator which is easily reactive does not mix, and to mix immediately before use.

The amounts of the thermoplastic elastomer (a), the (meth) acrylate monomer (b) and the polymerization initiator (c) in the dental polymerizable composition of the present invention are determined according to the amounts of the thermoplastic elastomer (a) used. Type and molecular weight,
It varies depending on the type of the (meth) acrylate-based monomer (b) and the like, but is usually a thermoplastic elastomer (a),
Based on the total of the (meth) acrylate-based monomer (b) and the polymerization catalyst (c), the thermoplastic elastomer (a) is 40 to 80% by weight, the (meth) acrylate-based monomer (b) is 60 to 20% by weight, When the polymerization catalyst (c) is 0.
The amount of component (a) is preferably 50 to 5% by weight.
-60% by weight, component (b) is 50-40% by weight, (c)
The component is 0.1-3% by weight.

The composition of the present invention has a number average molecular weight of 3 in addition to the thermoplastic elastomer (a), the (meth) acrylate monomer (b) and the polymerization initiator (c).
A polymer having no block of an aromatic vinyl monomer unit having a molecular weight of not less than 000 (hereinafter abbreviated as polymer (d)) was used to adjust the paste properties of the composition and the properties of the cured product. Can be added in an amount not exceeding 10% by weight.

As the polymer (d), known polymers are used without any particular limitation. Examples thereof include isoprene rubber, butadiene rubber, styrene-butadiene rubber (random copolymer), hydrogenated styrene-butadiene rubber, chloroprene rubber, Nitrile rubber, butyl rubber, ethylene-propylene rubber, chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, polysulfide rubber, silicone rubber, fluorine rubber, urethane rubber, polyolefin thermoplastic elastomer, polyurethane thermoplastic elastomer, polyester thermoplastic Elastomers such as elastomers, polyamide-based thermoplastic elastomers, 1,2-polybutadiene-based thermoplastic elastomers, ethylene-vinyl acetate-based thermoplastic elastomers, and polyvinyl chloride-based thermoplastic elastomers And the like. However, a liquid prepolymer having a relatively low molecular weight selected from polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, and derivatives thereof is not included in the polymer (d) of the present invention. The addition of these liquid prepolymers significantly increases the adhesion to the oral mucosa, making the impression manipulation in the oral cavity difficult. Further, as the polymer (d), polyethylene, polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate,
Polyethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polycarbonate, nylon, polyurethane, polychloroprene, polyvinyl fluoride, polyethylene oxide, polyoxymethylene, polyacrylonitrile, polyvinyl alcohol, polyvinylidene chloride, polyvinylidene fluoride, cellulose, polyester, Conventionally known polymers such as polyamide and cellulose acetate can also be used.

If necessary, a small amount of hydroquinone, hydroquinone monomethyl ether, butylhydroxyl toluene and the like may be added to the composition of the present invention as a polymerization inhibitor. In order to enhance the stability of the thermoplastic elastomer, a small amount of an antioxidant, a light stabilizer or the like can be added. Furthermore, in order to adjust the properties of the paste and the cured product to more suitable ones, various lubricants, surfactants,
Inorganic fillers, plasticizers and the like may be added in small amounts, and pigments, dyes, and fibers for mimic blood vessels may be added to give the composition a gingival color.

The composition of the present invention is usually provided as a paste by mixing a thermoplastic elastomer (a), a (meth) acrylate monomer (b), a polymerization initiator (c) and the like. As a mixing method of each component, a known method is used without any particular limitation, and examples thereof include kneading with a solvent and melt kneading. Specifically, a thermoplastic elastomer (a), (meth)
A method in which the acrylate monomer (b) and the polymerization initiator (c) are dissolved and uniformly mixed, and then the solvent is removed, or kneading is performed using a kneading machine such as Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.). And the like, whereby a uniform paste can be prepared. The resulting paste is
It is preferable to perform a defoaming treatment.

The dental polymerizable composition of the present invention has a consistency of 1
It is in the range of 3 or more and 40 or less, and has a paste property suitable for an impression operation in the oral cavity. More preferred consistency is
It is in the range of 15 or more and 35 or less. The term "consistency of the paste" as used in the present invention refers to a value measured by a method described in ISO 4823 (1992 version), which indicates the hardness of the paste and serves as an index of the fluidity of the paste. If the consistency of the paste is out of the above range, the impression operability in the oral cavity is impaired, which is not desirable.

[0038] The dental polymerizable composition of the present invention is excellent not only in the impression collecting property in the oral cavity but also in the property of retaining the shape after the impression is collected. Such a property is
The stress relaxation rate when the paste is plastically deformed by applying a certain load to the paste (in the present invention, a value measured by a method described in Examples described below is referred to as a stress relaxation rate) is quantitatively shown as an index. be able to.

The dental polymerizable composition of the present invention has a stress relaxation rate of 90% or more, and when the paste is plastically deformed, the force applied to maintain the plastic deformation is extremely small. For this reason, even if an impression is collected in the oral cavity, and it is removed from the oral cavity and left as it is, the obtained impression shape can be well maintained. If the stress relaxation rate of the paste is less than 90%, the obtained impression shape changes over time unless a force for maintaining the deformation is applied to the plastically deformed paste. This is undesirable because the compatibility of the rebase material obtained by curing it with the oral cavity is impaired.

The procedure for forming a rebase material from the composition of the present invention is as follows. That is, the composition of the present invention is laid on the mucosal surface of the denture base, and an impression is taken in the oral cavity. Thereafter, the denture base is removed by removing from the oral cavity and polymerizing and hardening by a method such as light irradiation or room temperature polymerization while maintaining the impression after collection.

As the rebase material of the composition of the present invention, a cured product having an appropriate rubber elasticity can be obtained by using the specific thermoplastic elastomer (a), and the rubber elasticity is maintained for a long time. Furthermore, by using the (meth) acrylate monomer (b), the water absorption of the obtained cured product is low, and a low value of water absorption is maintained over a long period of time. In addition, the amount of eluted substances from the cured product is small, and the contamination in the oral cavity can be suppressed low.

The composition of the present invention is not limited to a rebase material, and can be used as a material for dental wearing articles such as denture bases, orthodontic bases, temporary crowns, etc., which involve an impression operation in the oral cavity. Further, the present invention is not limited to the impression operation in the oral cavity, and can be used as a material for a dental polymerizable wearing article on a plaster model or the like.

[0043]

The present invention will be described in detail with reference to the following examples. Note that the present invention is not limited to the embodiment.

In this example, the paste properties and photocuring properties of the composition, the mechanical properties of the cured product obtained from the composition, and the amount of unpolymerized monomer were measured by the following methods.

(1) Consistency of composition Measured according to the method described in ISO 4823. That is, at 25 ° C., 0.5 ml of the composition is formed into a cylindrical shape having a diameter of 10 mm and placed on a glass plate. Another glass plate and a weight (total of 1500 g) are gently placed on the top of the columnar composition, and after 5 seconds, the glass plate 2 and the weight are removed. For the shape of the composition spread on the glass plate, the maximum and minimum dimensions between the parallel cut lines were determined, the average was calculated, and 1 m
Expressed in units of m. This test is repeated three times to obtain consistency.

(2) Depth of cure A stainless steel mold having a cylindrical hole with an inner diameter of 3 mm and a depth of 18 mm is placed on a light-shielded glass plate, and the composition is filled. After placing a slide glass on top of it and pressing it against it, a dental light irradiator [Alpha Light, manufactured by Kuraray Co., Ltd.]
The composition is cured by irradiation with light for one minute, and the thickness of the cured composition is measured with a vernier caliper.

(3) Rubber hardness of cured product The composition is filled into a mold having an inner diameter of 10 mm and a thickness of 10 mm,
Dental light irradiator [Alpha Light, Kuraray Co., Ltd.]
For 10 minutes and polymerized and cured, and the obtained cured product was used as a test piece. After the test piece was immersed in water at 37 ° C. for one day, the rubber hardness was measured using a durometer type A (manufactured by Furusato Seiki Seisakusho) according to JIS K6253.

(4) Determination of Unpolymerized Monomer A resin paste was filled in a mold having an inner diameter of 20 mm and a thickness of 1 mm, and was irradiated with light for 5 minutes using a dental light irradiator [alpha-light] to be polymerized. The weight of the obtained five cured products was measured, and the weight of the monomer contained in the sample was determined. Then, the polymer was immersed in 10 ml of methanol and extracted for 30 days at 37 ° C. to extract unpolymerized monomers. The extracted methanol solution was analyzed by high performance liquid chromatography (HPLC) using a reversed phase column. The amount of the unpolymerized monomer was determined by the calibration curve method, and the amount of the unpolymerized monomer (% by weight) was determined from the ratio to the amount of the monomer in the sample previously determined.

(5) Fatigue durability of cured product The composition is filled in a mold having a diameter of 10 mm and a thickness of 10 mm.
Irradiation with a dental light irradiator [alpha-light] for 10 minutes was carried out to polymerize and cure, and the resulting cured product was used as a test piece.
A compression fatigue test was performed in water at ℃. That is, the test piece was immersed in water at 37 ° C.
(Made by Shimadzu Corporation), repeating a sinusoidal wave (5 Hz) with a maximum compression load of 2 kgf and a minimum compression load of 0.2 kgf 1
It was given up to a million times and the change in displacement was observed. When the displacement reached 3 mm or more (30% of the total length of the test piece), the measurement was stopped at that time.

Example 1 Styrene-isoprene thermoplastic elastomer (SI
S), 60 g of Hybler VS-1 (manufactured by Kuraray Co., Ltd., hereinafter abbreviated as VS-1) having a styrene content of 20% by weight, n-lauryl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., hereinafter abbreviated as LM) ) 38 g, 1,10-decanediol dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd .; DD
2 g) and 1.0 g of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (hereinafter abbreviated as TMDPO) were dissolved and mixed at room temperature to form a paste. Tables 1 and 2 show the properties of the obtained paste and the mechanical properties of the cured product obtained from the paste.

Example 2 VS-1 60 g, LM 38 g, DD 2 g, TMD
PO 1.0g, CQ (Camphorquinone) 0.3
g and DMAEMA (dimethylaminoethyl methacrylate) 0.3 g were dissolved and mixed at room temperature to form a paste.
Tables 1 and 2 show the properties of the obtained paste and the mechanical properties of the cured product obtained from the paste.

Example 3 VS-1 60 g, LM 38 g, DD 2 g, TMD
1.0 g of PO, 0.5 g of CQ, and 0.5 g of 2-n-butoxyethyl N, N-dimethylaminobenzoate were dissolved and mixed at room temperature to form a paste. Tables 1 and 2 show the properties of the obtained paste and the mechanical properties of the cured product obtained from the paste.

Example 4 Styrene-isoprene thermoplastic elastomer (SI
S) JSR-SIS5000 (manufactured by Nippon Synthetic Rubber Co., Ltd.) 60 g, LM 38 g, DD 2 g, TMDPO
1.0 g was dissolved and mixed at room temperature to form a paste. Table 1 shows the properties of the obtained paste and the mechanical properties of the cured product obtained from the paste.

Example 5 60 g of VS-1, 38 g of stearyl methacrylate (manufactured by Kyoeisha Chemical), 2 g of DD, 1.5 g of TMDPO, C
Q 0.5 g, p-dimethylaminobenzophenone
0.5 g was dissolved and mixed at room temperature to form a paste. Table 1 shows the properties of the obtained paste, the mechanical properties and the water absorption of the cured product obtained from the paste, and the like.

Example 6 The resin paste prepared in Example 3 was mixed with the resin paste at 50 ° C.
After storage for months, the properties of the paste and the mechanical properties of the cured product obtained from the paste are shown in Table 1.

Comparative Example 1 VS-1 60 g, LM 38 g, DD 2 g, CQ
0.5 g of DMAEMA and 0.5 g of DMAEMA were dissolved and mixed at room temperature to form a paste. Table 1 shows the properties of the obtained paste and the mechanical properties of the cured product obtained from the paste.

[0057]

[Table 1]

[0058]

[Table 2]

As is clear from Table 1, the composition of the present invention has a paste property suitable for an impression operation in the oral cavity, has a high photocurability, has a very small amount of unpolymerized monomer, and may be eluted in the oral cavity. Is extremely low. Further, as is clear from Table 2, the polymer cured product has high fatigue durability, and has properties that are hard to set by repeated bite in the oral cavity.

Further, these compositions showed little change in color tone before and after polymerization and curing, and the resin paste was tasteless and odorless, and did not cause any discomfort even when the impression operation was performed in the oral cavity.

[0061]

According to the present invention, there is provided a dental polymerizable composition having a paste property capable of performing an impression operation in the oral cavity, the storage stability of the resin paste is high, and the resin paste is colored and before and after polymerization. There is little change in color tone. The cured product obtained from the composition of the present invention has mechanical properties that are stable for a long period of time, and has very little unpolymerized monomer elution, and is excellent in stain resistance.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mizuho Maeda 36, Towada, Kamisu-cho, Kashima-gun, Ibaraki Pref. Kuraray Co., Ltd. Inventor Eiichi Masuhara 2-5-11 Honkomagome, Bunkyo-ku, Tokyo (72) Inventor Naoto Masuhara 2-5-11 Honkomagome, Bunkyo-ku, Tokyo (72) Inventor Jiro Tarumi 2-6, Tsutsujigaoka, Akishima-shi, Tokyo 21-510

Claims (4)

[Claims] 1. A thermoplastic elastomer comprising (a) a thermoplastic polymer block (A) composed of an aromatic vinyl monomer having a number average molecular weight of 3,000 or more and an elastomer polymer block (B), each having one or more blocks. ,
(B) a (meth) acrylate monomer and (c) an acylphosphine oxide as a polymerization initiator,
A dental polymerizable composition having a consistency of 3 to 40. 2. An elastomeric polymer block (B) comprising:
The dental polymerizable composition according to claim 1, which is at least one kind of polymer block selected from polyisoprene and isoprene-butadiene copolymer, and is a thermoplastic elastomer polymer having a vinyl bond content of 40 mol% or more. 3. The method according to claim 1, wherein the acylphosphine oxide is 2,4,4.
The dental polymerizable composition according to claim 1, which is 6-trimethylbenzoyldiphenylphosphine oxide. 4. The dental polymerizable composition according to claim 1, wherein the polymerization initiator (c) is 2,4,6-trimethylbenzoyldiphenylphosphine oxide, camphorquinone and a reducing agent.