JP7783626B2 - Dental hardenable composition and kit - Google Patents

Description

The present invention relates to a hardenable composition that initiates polymerization by reacting an oxidizing agent with a reducing agent. More specifically, the present invention relates to a dental hardenable composition that exhibits good hardening behavior.

(Meth)acrylate-based materials are used in a wide range of fields, including paints, printing materials, adhesives, and dental materials. For example, in the dental field, they are used in a variety of materials, including bonding agents, resin cements, resin-reinforced glass ionomers, and composite resins. These materials typically cure through radical polymerization. Radicals are generated by one or more polymerization initiators selected from photopolymerization initiators, thermal polymerization initiators, and chemical (redox) polymerization initiators, depending on the application.

Of these polymerization initiators, chemical polymerization initiators are particularly useful in applications where it is difficult to apply light or heat stimuli. Because chemical polymerization initiators contain a combination of a reducing agent and an oxidizing agent that react immediately upon contact, they usually need to be stored in two or more separate forms. Chemical polymerization initiators can be stored in two separate forms, such as paste/paste, liquid/liquid, powder/liquid, or liquid/paste combinations.

It is desirable for chemical polymerization initiators used in dental materials to have temperature-dependent curing behavior that does not progress easily at room temperature, but progresses easily in the oral cavity. A long-known chemical polymerization initiator is a chemical polymerization initiator that combines benzoyl peroxide and a tertiary aromatic amine compound. However, this chemical polymerization initiator has a low temperature-dependent curing behavior, making it difficult to achieve the temperature-dependent curing behavior described above. In addition, benzoyl peroxide has poor thermal stability, resulting in poor storage stability.

In response to this, Patent Documents 1 and 2 propose radical polymerization initiators with improved storage stability. These radical polymerization initiators use hydroperoxides as oxidizing agents and various thiourea derivatives as reducing agents. Hydroperoxides have higher thermal stability and superior storage stability compared to benzoyl peroxide and the like. However, even with these radical polymerization initiators, the temperature dependence of the curing behavior is not high, and it is still difficult to achieve the desired temperature dependence of the curing behavior.

JP 2014-227370 A International Publication No. WO2014/156077

The present invention aims to provide a dental hardenable composition that exhibits desirable hardening behavior as a dental material.

The present inventors have investigated dental hardenable compositions to solve the above problems, and as a result have found dental hardenable compositions that have desirable hardening behavior as dental materials.
That is, the dental curable composition according to one embodiment of the present invention comprises:
100 parts by mass of (A) polymerizable monomer;
0.05 to 5 parts by mass of a peroxyester compound (B);
0.001 to 0.05 parts by mass of (C) a divalent copper compound;
0.05 to 2.5 parts by mass of (D) a saccharin compound;
0.05 to 2.5 parts by mass of (E) a reducing agent for copper;
The compound is characterized by containing

In the dental hardenable composition, (E) is preferably at least one of (e1) an aromatic amine compound having no electron-withdrawing group, (e2) a (thio)barbituric acid compound, (e3) a thiourea compound, and (e4) a heterocyclic thiol compound.

In the dental hardenable composition described above, if the time from mixing (A) to (E) at 23°C until the temperature starts to rise while maintaining the composition at 23°C is t1 (seconds), and the time from maintaining the composition at 37°C until the temperature reaches its exothermic peak is t2 (seconds), then it is preferable that t1 - t2 be 50 seconds or longer.

It is preferable that the above dental hardenable composition further contains 50 to 1,500 parts by mass of a filler (F).

The kit for preparing the dental curable composition according to one aspect of the present invention includes:
It is composed of a first agent and a second agent that are isolated from each other,
(A) is contained in at least one of the first agent and the second agent,
(B) and (C) are contained in the first agent but not in the second agent;
The (D) and (E) are not contained in the first agent, but are contained in the second agent.

The present invention makes it possible to provide a dental hardenable composition that exhibits desirable hardening behavior as a dental material.

1 is a graph illustrating the operation time t1 of a dental hardenable composition. 1 is a graph illustrating the hardening time t2 of a dental hardenable composition.

1. Overview of Dental Hardenable Composition A dental hardenable composition according to one embodiment of the present invention is configured so as to be suitable for use as a dental material, such as a dental resin cement or a dental core build-up material. The dental hardenable composition according to this embodiment contains (A) a polymerizable monomer, (B) a peroxyester compound, (C) a divalent copper compound, (D) a saccharin compound, and (E) a reducing agent for copper. Components that may be contained in the dental hardenable composition according to this embodiment will be described in detail below.

In this specification, unless otherwise specified, the expression "x to y" using the numerical values x and y means "greater than or equal to x and less than or equal to y." In such expressions, when a unit is assigned only to the numerical value y, the unit also applies to the numerical value x. Furthermore, in this specification, the term "(meth)acrylate" means both "acrylate" and "methacrylate," and the term "(meth)acryloyl" means both "acryloyl" and "methacryloyl."

2. Constituents of Dental Curable Composition 2-1 (A) Polymerizable Monomer The dental curable composition according to this embodiment uses a polymerizable monomer (A) as the main component. The polymerizable monomer (A) is a compound having at least one radically polymerizable unsaturated group in one molecule. The dental curable composition according to this embodiment is cured by radical polymerization of the polymerizable monomer (A).

The polymerizable monomer (A) can be any known compound containing one or more radically polymerizable unsaturated groups in one molecule, without any particular restrictions. Examples of radically polymerizable unsaturated groups contained in the polymerizable monomer (A) include acryloyl groups, methacryloyl groups, acrylamide groups, methacrylamide groups, and styryl groups. From the standpoint of curability, the dental hardenable composition according to this embodiment preferably uses, as the polymerizable monomer (A), a compound containing at least one of an acryloyl group, a methacryloyl group, an acrylamide group, or a methacrylamide group as a radically polymerizable unsaturated group.

(A) Examples of monofunctional and polyfunctional monomers that can be suitably used as the polymerizable monomer include the following: Monofunctional monomers include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, glycidyl (meth)acrylate, 2-cyanomethyl (meth)acrylate, benzyl methacrylate, polyethylene glycol mono(meth)acrylate, allyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and glyceryl mono(meth)acrylate. Examples of polyfunctional monomers include 2,2'-bis{4-[2-hydroxy-3-(meth)acryloyloxypropoxy]phenyl}propane, triethylene glycol methacrylate, 2,2-bis[(4-(meth)acryloyloxypolyethoxyphenyl)propane], 1,6-bis(methacrylethyloxycarbonylamino)-2,2,4-trimethylhexane, 1,6-bis(methacrylethyloxycarbonylamino)-2,4,4-trimethylhexane, and trimethylolpropane trimethacrylate. (A) Polymerizable monomers may be used alone or in combination of two or more.

2-2 (B) Peroxyester Compound In the dental curable composition of this embodiment, a peroxyester compound (B) is used as an oxidizing agent. It is presumed that the peroxyester compound (B) undergoes an oxidation-reduction reaction with the divalent copper compound (C), the saccharin compound (D), and the reducing agent for copper (E), thereby generating initiation radicals necessary for curing.

(B) A peroxyester compound is a compound having a structure represented by R-C(=O)-O-O-R' (where R and R' are any organic groups) or R-O-C(=O)-O-O-R' (where R and R' are any organic groups). In this embodiment, peroxyester compounds having such a structure can be used as the oxidizing agent without any particular restrictions. Specific examples of peroxyester compounds that can be suitably used in this embodiment include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxydecanoate, t-hexyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, t-hexyl peroxy-2-ethylhexanoate, t- Examples of peroxyalkylene compounds include butylperoxy-2-ethylhexanoate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-di(benzoylperoxy)hexane, t-butylperoxyacetate, t-butylperoxy-3-methylbenzoate, and t-butylperoxybenzoate. In the dental curable composition according to this embodiment, from the viewpoints of polymerization activity and storage stability, it is preferable to use as the (B) peroxyester compound a peroxyester compound having a 10-hour half-life temperature of 80°C or higher, and it is particularly preferable to use at least one of t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxy-2-ethylhexyl monocarbonate, t-butylperoxyacetate, and t-butylperoxybenzoate. As the (B) peroxyester compound, a single type may be used, or two or more types may be used in combination.

The amount of the peroxyester compound (B) in the dental curable composition according to this embodiment is 0.05 to 5 parts by mass, and preferably 0.25 to 2.5 parts by mass from the viewpoint of curability, per 100 parts by mass of the polymerizable monomer (A).

2-3 (C) Divalent Copper Compound In the dental curable composition according to this embodiment, a divalent copper compound (C) is used as a catalyst. The divalent copper compound (C) is reduced by a saccharin compound (D) and a reducing agent for copper (E). It is presumed that the reduced copper compound undergoes an oxidation-reduction reaction with a peroxyester compound (B), thereby generating an initiating radical.

(C) The divalent copper compound may be a hydrate or anhydrous. Examples of divalent copper compounds that can be suitably used in this embodiment include copper(II) chloride, copper(II) sulfate pentahydrate, copper(II) nitrate, copper(II) trifluoromethanesulfonate, copper(II) acetate monohydrate, copper(II) acetylacetonate, copper(II) naphthenate, copper(II) salicylate, copper(II) benzoate, copper(II) methacrylate, copper(II) butyl phthalate, copper(II) gluconate, dichloro(1,10-phenanthroline)copper(II), ethylenediaminetetraacetate copper(II) disodium tetraacetate tetrahydrate, copper(II) dimethyldithiocarbamate, copper(II) diethylthiocarbamate, copper(II) hexafluoroacetylacetonate, bis(1,3-propanediamine)copper(II) dichloride, and bis(8-quinolinolato)copper(II). In the dental curable composition according to this embodiment, from the viewpoint of storage stability, it is preferable to use at least one of copper(II) acetate monohydrate and copper(II) acetylacetonate as the divalent copper compound (C). As the divalent copper compound (C), one type may be used alone, or two or more types may be used in combination.

The amount of the divalent copper compound (C) in the dental curable composition according to this embodiment is 0.001 to 0.05 parts by mass, and preferably 0.005 to 0.03 parts by mass from the viewpoint of storage stability, per 100 parts by mass of the polymerizable monomer (A).

2-4 (D) Saccharin Compound In the dental curable composition according to this embodiment, a saccharin compound (D) is used as a polymerization accelerator. It is presumed that the saccharin compound (D) accelerates the oxidation-reduction reaction by interacting with the divalent copper compound (C) and the reducing agent for copper (E).

(D) The saccharin compound is a compound represented by the following general formula (1):
(Here, in general formula (1), M represents a hydrogen atom or a metal atom. R ₁ represents an alkyl group having 1 to 5 carbon atoms, an unsaturated chain hydrocarbon group having 2 to 5 carbon atoms, a halogen atom, a silyl group, or an alkylsilyl group. n represents an integer of 0 to 4. However, when n is 2 to 4 and multiple R _1s are present, the multiple R _1s may be the same or different.)

In the dental curable composition according to this embodiment, it is preferable to use at least one of saccharin, saccharin sodium, and saccharin denatonium as the saccharin compound (D), and it is more preferable to use saccharin from the viewpoint of solubility in the polymerizable monomer (A).

The amount of the saccharin compound (D) in the dental hardenable composition according to this embodiment is 0.05 to 2.5 parts by mass, and preferably 0.3 to 1 part by mass from the viewpoint of hardenability, per 100 parts by mass of the polymerizable monomer (A).

2-5 (E) Reducing Agent for Copper In the dental hardenable composition according to this embodiment, a reducing agent for copper (E) is used. As the reducing agent for copper (E), any compound having the ability to reduce the divalent copper contained in the divalent copper compound (C) to monovalent copper or zero-valent copper can be used without particular limitation. In the dental hardenable composition according to this embodiment, it is preferable to use at least one of (e1) an aromatic amine compound having no electron-withdrawing group, (e2) a (thio)barbituric acid compound, (e3) a thiourea compound, and (e4) a heterocyclic thiol compound as the reducing agent for copper (E).

(e1) An aromatic amine compound having no electron-withdrawing group is characterized in that the aromatic ring does not have an electron-withdrawing group such as an ester group, an amide group, a nitrile group, or a nitro group. (e1) Examples of compounds used as an aromatic amine compound having no electron-withdrawing group include p-dimethylaminotoluidine, p-diethylaminotoluidine, p-diethanolaminotoluidine, p-dimethylaniline, and p-dimethylamino tertiary butylbenzene. In the dental curable composition according to this embodiment, from the viewpoint of storage stability, it is preferable to use p-diethylaminotoluidine as the (e1) aromatic amine compound having no electron-withdrawing group.

(e2) The (thio)barbituric acid compound is a compound represented by the following general formula (2):
(Here, in general formula (2), X represents O or S. _{R 2} , R ₃ , R ₄ and R ₅ each represent hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, a halogen group such as a chloro group, a hydroxyl group, an amino group, or a nitro group. _{R 2} , R ₃ , R ₄ and R ₅ may be the same or different.)

(e2) Examples of (thio)barbituric acid compounds include barbituric acid, thiobarbituric acid, 1,3,5-trimethylbarbituric acid, 1-phenyl-5-benzylbarbituric acid, 1-benzyl-5-phenylbarbituric acid, 1,3-dimethylbarbituric acid, 1,3-dimethyl-5-phenylbarbituric acid, 1-cyclohexyl-5-ethylbarbituric acid, 5-laurylbarbituric acid, 5-butylbarbituric acid, 5-allylbarbituric acid, 5-hydroxy-5-butylbarbituric acid, 5-phenylthiobarbituric acid, 1,3-dimethylthiobarbituric acid, 5,5-dibromobarbituric acid, trichlorobarbituric acid, 5-nitrobarbituric acid, 5-aminobarbituric acid, 5-hydroxybarbituric acid, and 5,5-dihydroxybarbituric acid. In the dental hardenable composition according to this embodiment, from the viewpoint of hardenability, it is preferable to use 1-cyclohexyl-5-ethylbarbituric acid as the (thio)barbituric acid compound (e2).

(e3) Thiourea compound refers to a compound having the structure =N-C(=S)-N=. As the (e3) thiourea compound, it is preferable to use a thiourea compound represented by the following general formula (3):
(Here, in general formula (3), R ₆ , R ₇ , and R ₈ each represent a hydrogen atom, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted acyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted alkenyl group. R ₇ may bond with R ₆ or R ₈ to form a ring.)

In the dental hardenable composition according to this embodiment, from the viewpoint of hardenability, it is preferable to use N-benzoylthiourea, (2-pyridyl)thiourea, or ethylenethiourea as the thiourea compound (e3).

(e4) The heterocyclic thiol compound is a compound represented by the following general formula (4):
(Here, in general formula (4), X represents O, S, or N-R _11. R ₉ , R ₁₀ , and R ₁₁ each represent hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, a halogen group such as a chloro group, a hydroxyl group, an amino group, or a nitro group. _{R 9} , R ₁₀ , and R ₁₁ may be the same or different. R ₁₀ may be bonded to R ₉ to form a ring.)

Examples of the heterocyclic thiol compound (e4) include 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptooxazole, 2-mercaptoimidazole, 2-mercaptothiazole, 6-methyl-1,3-benzoxazole-2-thiol, 5-phenylbenzoxazole-2-thiol, and 4,5-diphenyl-2-mercaptooxazole. In terms of curability, the dental hardenable composition according to this embodiment preferably uses at least one of 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, and 2-mercaptobenzothiazole as the heterocyclic thiol compound (e4), and more preferably uses 2-mercaptobenzoxazole.

In the dental hardenable composition according to this embodiment, from the viewpoint of aesthetics, it is preferable to use at least one of (e2) a (thio)barbituric acid compound, (e3) a thiourea compound, and (e4) a heterocyclic thiol compound as the reducing agent for copper (E). Furthermore, in consideration of hardenability, it is even more preferable to use (e4) a heterocyclic thiol compound as the reducing agent for copper (E). Only one type of reducing agent for copper (E) may be used, or two or more types may be used in combination.

In addition, the amount of reducing agent (E) relative to copper in the dental hardenable composition according to this embodiment is 0.05 to 2.5 parts by mass, and preferably 0.25 to 1 part by mass from the viewpoint of hardening, per 100 parts by mass of polymerizable monomer (A).

2-6 Other Components The dental curable composition according to this embodiment may contain other components as appropriate, provided that the effects of the invention are not impaired. Examples of other components include (F) a filler, a polymerization inhibitor, an ultraviolet absorber, a pigment, etc.

Specifically, in the dental curable composition according to this embodiment, it is preferable to use at least one of silica, zirconia, silica-zirconia, and polymethacrylic acid as the filler (F) in order to enhance polishability and mechanical strength. The filler (F) may be treated with a surface treatment agent, such as a silane coupling agent. The amount of filler (F) blended is preferably 50 to 1,500 parts by mass, and more preferably 70 to 1,000 parts by mass, per 100 parts by mass of the polymerizable monomer (A).

In the dental hardenable composition according to this embodiment, at least one of hydroquinone, hydroquinone monomethyl ether, and dibutylhydroxytoluene can be used as a polymerization inhibitor.

3. Hardening Behavior of Dental Hardenable Composition The dental hardenable composition is configured to be hardened in the oral cavity after preparation by mixing or other operations outside the oral cavity during patient treatment. For this reason, it is preferable that the dental hardenable composition does not harden outside the oral cavity from the viewpoint of ensuring sufficient time for preparation so as to ensure the reliability of treatment. On the other hand, it is preferable that the dental hardenable composition hardens easily inside the oral cavity from the viewpoint of reducing the burden on the patient due to restrictions on movement during hardening, etc. Based on these requirements, the dental hardenable composition according to this embodiment is configured to easily achieve both hardness in hardening outside the oral cavity and easy hardening in the oral cavity.

In this embodiment, assuming that the room temperature outside the oral cavity is 23°C, the extraoral curing behavior of the dental hardenable composition is evaluated based on the operation time t1, which is the time from mixing the components ((A) to (E) above) at 23°C until the dental hardenable composition begins to harden when the composition is maintained at 23°C. For a dental hardenable composition, the operation time t1 corresponds to the time available for various preparatory operations. Because the hardening reaction of a dental hardenable composition is an exothermic reaction, the operation time t1 can be defined as the time from the start of mixing the components until the temperature begins to rise. For the dental hardenable composition according to this embodiment, it is preferable that the operation time t1 be appropriately long, for example, 90 to 720 seconds is preferable, and 150 to 360 seconds is more preferable.

In this embodiment, an example of a method for determining the operation time t1 of the dental hardenable composition will be described. Figure 1 is a graph in which the horizontal axis represents the time elapsed since the start of mixing of the components, and the vertical axis represents the temperature of the dental hardenable composition. Figure 1 also shows a curve obtained by plotting the measured temperature values of the dental hardenable composition at each time. In this embodiment, the operation time t1 can be determined as the time at which the temperature changes from a constant linear portion of the curve to a monotonically increasing portion.

In addition, in this embodiment, assuming that the temperature inside the oral cavity is 37°C, the hardening behavior of the dental hardenable composition inside the oral cavity is evaluated based on the hardening time t2, which is the time required for the dental hardenable composition to completely harden when the components (above (A) to (E)) are mixed at 23°C and then maintained at 37°C. Because the hardening reaction of the dental hardenable composition is an exothermic reaction, the hardening time t2 can be defined as the time from the start of mixing the components until the temperature reaches its exothermic peak. For the dental hardenable composition according to this embodiment, it is preferable that the hardening time t2 be appropriately short, for example, 120 to 600 seconds is preferable, and 150 to 300 seconds is more preferable.

In this embodiment, an example of a method for determining the curing time t2 of a dental curable composition will be described. Figure 2 is a graph in which the horizontal axis represents the time elapsed since the start of mixing of the components, and the vertical axis represents the temperature of the dental curable composition. Figure 2 also shows a curve obtained by plotting the measured temperature of the dental curable composition at each time. In this embodiment, the curing time t2 can be determined as the time at which the exothermic peak is reached on the curve. The position of the exothermic peak on the curve can be obtained as the intersection of a horizontal line L1 tangent to the highest temperature portion of the curve and an extrapolated line L2 of the portion where the temperature rise can be considered to be substantially constant.

As described above, in the dental hardenable composition of this embodiment, in order to achieve both resistance to hardening outside the oral cavity and ease of hardening within the oral cavity, it is preferable that the operation time t1 be sufficiently longer than the hardening time t2. Specifically, in the dental hardenable composition of this embodiment, in order to obtain more desirable hardening behavior as a dental material, it is preferable that the difference (t1 - t2) between the operation time t1 (seconds) and the hardening time t2 (seconds) is 50 seconds or more.

4. Kit for Preparing Dental Curable Composition The dental curable composition according to this embodiment is prepared as a kit consisting of a first part and a second part that are isolated from each other to prevent progress of curing during storage or distribution. In the kit according to this embodiment, the first part and the second part are isolated by an inhibitor that inhibits molecular diffusion between them, thereby preventing physical contact between them. Typically, in the kit according to this embodiment, the first part and the second part are individually contained and held in various containers, such as syringes, bags, and bottles, that serve as inhibitors. The containers and bags that contain the first and second parts are preferably capable of blocking external air and external light, and can be formed, for example, from resin, glass, metal, ceramics, etc. However, the inhibitor is not limited to the above configuration as long as it is capable of isolating the first part and the second part.

In the kit according to this embodiment, from the viewpoint of storage stability, it is preferable that the components contained in the first agent and the second agent are a combination of components that do not react with each other. From this viewpoint, for example, a combination of (B) a peroxyester compound and (C) a divalent copper compound, which do not react with each other, can be configured so that it is contained in the first agent but not in the second agent. In this case, a combination of (D) a saccharin compound and (E) a reducing agent for copper, which do not react with each other, can be configured so that it is contained in the second agent but not in the first agent. The (A) polymerizable monomer can be contained in at least one of the first agent and the second agent; that is, it may be contained in either the first agent or the second agent, or in both the first and second agents.

5. Examples The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

5-1 Raw Materials First, the substances used as raw materials in the Examples and Comparative Examples and their abbreviations are listed below.

-(A) Polymerizable monomers Bis-GMA: 2,2'-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane 3G: triethylene glycol dimethacrylate D-2,6E: 2,2-bis(4-methacryloyloxypolyethoxyphenyl).

- (B) Peroxyester Compounds BPT: t-butylperoxy-3,5,5-trimethylhexanoate BPB: t-butylperoxy-benzoate.

-(C) Divalent copper compound Cu(acac)2: acetylacetonate copper(II)
Cu(OAc)2: Copper(II) acetate monohydrate Cu(OTf)2: Copper(II) trifluoromethanesulfonate.

- (D) Saccharin Compounds: Saccharin.

- (E) Reducing agents for copper: CEBA: 1-cyclohexyl-5-ethyl-barbituric acid; PEAT: N,N-diethylamino-p-toluidine; BzTU: N-benzoylthiourea; MBT: 2-mercaptobenzothiazole; MBO: 2-mercaptobenzoxazole; DEPT: p-diethanolaminotoluidine; PyTU: (2-pyridyl)thiourea.

- (F) Filler F1: Silica zirconia filler with an average particle size of 3 μm F2: Silica zirconia filler with an average particle size of 0.2 μm

-Other ingredients: BHT: dibutylhydroxytoluene, BPO: benzoyl peroxide, TMBH: 1,1,3,3-tetramethylbutyl hydroperoxide.

5-2 Preparation of Dental Hardenable Compositions Dental hardenable compositions were prepared for Examples 1 to 22 and Comparative Examples 1 to 6. Each dental hardenable composition according to each Example and Comparative Example was prepared as a kit consisting of a first part and a second part. That is, for each Example and Comparative Example, the dental hardenable composition was obtained by mixing the first part and the second part at a volume ratio of 1:1. Table 1 shows the compositions of the first and second parts according to Examples 1 to 22, excluding the (F) filler, and Table 2 shows the compositions of the first and second parts according to Comparative Examples 1 to 6, excluding the (F) filler. In each of Examples 1 to 22 and Comparative Examples 1 to 6, 75 parts by mass of F1 and 50 parts by mass of F2 were added to the first and second parts, respectively. Note that in Tables 1 and 2, the parenthesized numbers for each component indicate the amount (parts by mass) of each component, and an upward arrow indicates the same composition as the column immediately above.

Specifically, Example 1 will be described. A first agent was prepared by mixing 50 parts by weight of (A) polymerizable monomer consisting of 5 parts by weight of Bis-GMA, 20 parts by weight of 3G, and 25 parts by weight of D-2,6E with 1.5 parts by weight of BPT, 0.01 parts by weight of Cu(acac)2, 75 parts by weight of F1, and 50 parts by weight of F2. A second agent was prepared by mixing 50 parts by weight of (A) polymerizable monomer consisting of 5 parts by weight of Bis-GMA, 20 parts by weight of 3G, and 25 parts by weight of D-2,6E with 0.75 parts by weight of saccharin, 0.5 parts by weight of MBO, 75 parts by weight of F1, and 50 parts by weight of F2. The first and second agents thus prepared were filled into the paste container of an automix syringe "Estecem II" (manufactured by Tokuyama Dental Co., Ltd.). When mixing the first and second parts to obtain the dental hardenable composition, a mixing tip for cement (manufactured by Tokuyama Dental Co., Ltd.) was attached to the tip of the paste container, and equal amounts of the first and second parts were mixed at a volume ratio of 1:1 to obtain the dental hardenable composition.

For Examples 2 to 22 and Comparative Examples 1 to 6, dental curable compositions were prepared in the same manner as in Example 1 above, except for the composition, which was changed as shown in Tables 1 and 2.

5-3 Evaluation of Dental Curable Compositions The dental curable compositions according to Examples 1 to 22 and Comparative Examples 1 to 6 were evaluated for working time t1 and curing time t2.

For the operation time t1, the first and second parts of the dental hardenable compositions of each Example and Comparative Example were mixed at a volume ratio of 1:1 using a mixing tip, and the resulting composition was immediately loaded into a mold for a thermocouple device maintained at 23±1°C. In the resulting curve, the starting point where the temperature deviates from the linear portion where the temperature remained constant after loading to the higher temperature side over time was determined, and the operation time t1 was defined as the time from the start of mixing to the starting point. For each dental hardenable composition, an operation time t1 of 90 seconds or longer was considered to be satisfactory. Furthermore, for each dental hardenable composition, if no hardening was confirmed even after 720 seconds, it was considered to be "unhardened."

For the curing time t2, the first and second parts of the dental hardenable compositions of each Example and Comparative Example were mixed at a volume ratio of 1:1 using a mixing tip, and the resulting composition was placed in a mold for a thermocouple device maintained at 37±1°C 30 seconds after mixing. The intersection of the horizontal line tangent to the highest temperature and the extrapolated line of the part where the temperature rise could be considered substantially constant was determined for the resulting curve, and the time from the start of mixing to the intersection was defined as the curing time t2. For each dental hardenable composition, a curing time t2 of 600 seconds or less was considered to be satisfactory. Furthermore, for each dental hardenable composition, if no hardening was confirmed even after 600 seconds, it was considered to be "unhardened."

Furthermore, for the dental hardenable compositions of Examples 1 to 22 and Comparative Examples 1 to 6, the difference (t1 - t2) between the working time t1 (seconds) and the hardening time t2 (seconds) was calculated using the working time t1 and hardening time t2 determined as described above. For each dental hardenable composition, a difference of t1 - t2 of 50 seconds or longer was determined to be satisfactory.

Table 3 shows the evaluation results for dental hardenable compositions according to Examples 1 to 22, and Table 4 shows the evaluation results for dental hardenable compositions according to Comparative Examples 1 to 6. Tables 3 and 4 also show the pass/fail judgment results, where a sample is deemed to have passed if the operation time t1, curing time t2, and t1-t2 are all satisfactory, and a sample is deemed to have failed if at least one of the operation time t1, curing time t2, and t1-t2 is not satisfactory.

As shown in Table 3, all of the dental hardenable compositions according to Examples 1 to 22 passed the test. On the other hand, as shown in Table 4, all of the dental hardenable compositions according to Comparative Examples 1 to 6 failed the test. Specifically, Comparative Example 1, which did not contain (B) a peroxyester compound, Comparative Example 2, which did not contain (C) a divalent copper compound, Comparative Example 3, which did not contain (D) a saccharin compound, and Comparative Example 4, which did not contain a reducing agent for copper, failed due to not curing. Furthermore, Comparative Examples 5 and 6, which used a chemical polymerization initiator with a different configuration from the above embodiment, failed because t1-t2 was less than 50 seconds.

Claims (4)

100 parts by mass of (A) polymerizable monomer;
0.05 to 5 parts by mass of a peroxyester compound (B);
0.001 to 0.05 parts by mass of (C) a divalent copper compound;
0.05 to 2.5 parts by mass of a saccharin compound (D) represented by the following general formula (1) ;
0.05 to 2.5 parts by mass of (E) a reducing agent for copper;
Contains
When the time from mixing (A) to (E) at 23°C until the temperature starts to rise while maintaining the temperature at 23°C is t1 (seconds), and the time from maintaining the temperature at 37°C until the temperature reaches an exothermic peak while maintaining the temperature at 37°C is t2 (seconds), t1 - t2 is 50 seconds or more.
A dental hardenable composition comprising:
(In general formula (1), M represents a hydrogen atom or a metal atom. R ₁ represents an alkyl group having 1 to 5 carbon atoms, an unsaturated chain hydrocarbon group having 2 to 5 carbon atoms, a halogen atom, a silyl group, or an alkylsilyl group. n represents an integer of 0 to 4. However, when n is 2 to 4 and multiple R _1s are present, the multiple R _1s may be the same or different.) 2. The dental hardenable composition according to claim 1, wherein (E) is at least one of (e1) an aromatic amine compound having no electron-withdrawing group, (e2) a (thio)barbituric acid compound, (e3) a thiourea compound, and (e4) a heterocyclic thiol compound. 3. The dental hardenable composition according to claim 1 , further comprising 50 to 1500 parts by mass of a filler (F). It is composed of a first agent and a second agent that are isolated from each other,
(A) is contained in at least one of the first agent and the second agent,
(B) and (C) are contained in the first agent but not in the second agent;
2. The kit for preparing a dental hardenable composition according to claim 1, wherein (D) and (E) are not contained in the first part but are contained in the second part.