JPH085769B2 - Photopolymerizable resin composition for making clasp patterns - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] In manufacturing a partial denture according to the present invention, the denture is grasped (resistance to lateral movement) and maintained (resistance to attachment / detachment).
And the support (resistance to occlusal pressure), the casting clasp, which is the metal component that gives the support (resistance to occlusal pressure), is manufactured by the lost wax method. It relates to a photopolymerizable resin composition for making.

[Conventional technology]

Clasps are used in more than 90% of the main and indirect maintenance devices for partial dentures. However, especially in the case of a casting clasp, the manufacturing method is complicated, and the maintenance power, the fitting accuracy, and the shape of the given arm are not always satisfactory.

In the conventional method of manufacturing a casting clasp, first, a jaw impression in a patient's mouth is taken, and a working model is made with cemented plaster. Next, in order to design the clasp which becomes the maintenance device, the maintenance tooth portion on this working model is surveyed. In addition, surveying is a work performed to find the remaining teeth on the model and the maximum protuberance of the ridge, and at the same time, to check the mutual parallel relationship.
It is an extremely important work for denture manufacture when the purpose is to be examined, such as the Meiji period at the blockout section, the measurement of the undercut amount, and the determination of the clasp position.

The important factors that influence the clasp retention force are the length and thickness of the clasp arm, the cross-sectional shape, the Young's modulus of the alloy used, the set undercut amount, and the curvature of the tooth flank of the maintenance tooth. To be When a casting clasp is manufactured using a paraffin wax pattern, the clasp retention force can be controlled by selecting the amount of undercut used, the thickness of the pattern, and the type of cross-section. At the time of denture design and denture design, a clasp design corresponding to the condition of the periodontal tissue of the maintenance tooth is required.

After the design / blockout of the working model is completed, the maintenance tooth part that has been blocked out according to the design is taken again to make a wax pattern of the clasp (composite impression), and the working model is invested in the model. Replace with. Next, while carefully controlling the clasp maintenance power in a precise phrase, while bending the clasp pattern of the paraffin wax with your fingers, attach it to the model investment material with an adhesive and mold the rest part and legs. Perform sprue planting. Next, without removing the paraffin-type wax clasp pattern from the model investment material, bury the model investment material together with the casting investment material, and after the investment material has hardened, heat the paraffin-based clasp pattern with the furnace. After incineration, melted metal is poured into the mold of the clasp pattern and cooled, and then indexed and polished to complete the clasp. (Hereinafter, this method will be referred to as "embedding method for each mold.") [Problems to be solved by the invention] The casting clasp manufacturing method described above and the material for forming the urasp pattern are paraffin waxes. It includes such problems as.

The paraffin type wax cannot be elastically deformed at all and is plastically deformed, so it cannot be removed from the undercut portion of the maintenance tooth on the working model through the maximum ridge.

If it is forcibly removed, permanent deformation will occur and accurate adaptation cannot be obtained. For this reason, it is not possible to build an accurate clasp with controlled maintenance. Therefore, the clasp pattern of the paraffin wax is always double-impressed with the working model and replaced with the investment material for the model, the clasp pattern is formed on the investment material for the model, and the investment material for the model is embedded with the investment material for casting. The so-called burial method must be performed for each type. For this reason, the clasp manufacturing process is complicated and takes a long time, and the material cost becomes large.

The plaque-in wax clasp pattern does not adhere to the investment material for the model or plaster, so be sure to use a special adhesive. Therefore, the thickness of the adhesive is about 50 μm
It becomes a clasp with an error of, and it is not possible to obtain a clasp with a good fit.

The clasp pattern of the paraffin type wax is bonded with pressure to the model investment material by pressure contact with fingers using an adhesive.
At that time, since the strength of the investment material is low, the particles of the investment material are peeled off and the morphology and surface quality of the maintenance tooth are deteriorated. Further, the particles that have fallen off of the investment material adhere to the clasp pattern of the paraffin wax and a casting clasp with good surface quality cannot be obtained.

The clasp pattern of a paraffin wax is a polymer with high crystallinity and a relatively low molecular weight, and the glass transition temperature Tg and melting point Tm are very close to each other, but it is a substance that does not have a glass transition point like a metal. If the temperature rise rate is too high during heating and incineration, the melted wax will boil, and the wax that has become a gas will expand, so that it will be suddenly pressurized and cracks will occur in the investment material or the inner surface of the investment material will become rough.

In order to solve the above problems, the present invention is intended to develop a clasp pattern made of a new material that replaces the paraffin wax.

[Means for solving problems]

As a result of intensive studies to solve the above problems, the present inventors have developed a photopolymerizable resin composition, which is a new material replacing the clasp pattern of paraffin wax. First, respective means for solving the above problems will be described.

The impression of the conventional working model is taken again and the clasp pattern is made by replacing it with the investment material for the model, and the investment material for the model is embedded by the investment material for casting. A clasp pattern made of a polymerized resin composition is used to bond and mold the clasp pattern to a working model, polymerize it with visible light, and remove it from the working model and bury it in a casting embedding material for manufacturing. Do the way. For this purpose, at the stage of adhering and molding the clasp pattern to the work model, it has a high degree of plasticity and can be freely deformed like the conventional wax, and it can be immediately irradiated with active energy rays such as visible light and ultraviolet rays. A material that hardens to become an elastic body and does not deform at all even if it is not removed from the work model is required.

The photopolymerizable resin composition of the present invention is as described above,
It has the property that it does not break even if it is not removed with a change of up to about 0.5 mm from the undercut part of the slap wearing part through the maximum bump part and it returns to the original shape accurately. . When making a casting clasp using the photopolymerized clasp pattern of this material, the steps of taking an impression of the maintenance tooth part on the working model and replacing the investment material for the model can be deleted, so it took about 8 hours. It was possible to shorten the time to about 4 hours and to reduce the material costs of precision impression materials and investment materials for models that were used in the past.

The material of the composition obtained according to the present invention has a good compatibility with gypsum unlike paraffin wax, and can be easily removed after curing by appropriately adhering to gypsum without using an adhesive. I can. Therefore, it is possible to produce a casting clasp with good fitting accuracy by preventing the bad fitting due to the thickness of the conventional adhesive film.

The material of the composition obtained according to the present invention has a good influence on the morphology and surface quality of the maintenance tooth because the composition does not peel off due to the pressure contact of the fingers because it adheres to the investment material properly without using an adhesive. Don't give. Further, since the investment material particles do not adhere to the clasp pattern, it is possible to produce a cast clasp with good surface properties.

The material of the composition obtained by the present invention is a crystalline polymer, which is composed of a crystalline part (where the molecules are oriented) and an amorphous part (where the molecules are not oriented).
There is a glass transition point Tg near ℃, it gradually softens up to near the decomposition temperature of the cured product that has become a thermosetting resin, then carbonizes, and finally it is incinerated by carbon dioxide and water. .
Therefore, it was possible to obtain a good casting clasp with a casting surface free from the boiling expansion and cracking of the investment material due to rapid pressurization and the inner surface of the investment material which were found to be rough in the clasp pattern of conventional paraffin wax.

Among the compounds of the present invention, which are solid at room temperature and which contain at least one ethylenically unsaturated double bond and are polymerizable for polymerization, an example of a monofunctional methacrylate is methoxy polyethylene glycol 1000 methacrylate, which is a monofunctional methacrylate. An example of acrylate is methoxy polyethylene glycol 1000 acrylate, and an example of polyfunctional methacrylate is diisocyanate methylbenzene and 2
-Reaction product with hydroxyethyl methacrylate (trade name Art Resin SH-100, product of Negami Kogyo Co., Ltd.), Reaction product with diisocyanate methylcyclohexane and 2-hydroxyethyl methacrylate (trade name Art Resin SH
-200, product of Negami Kogyo Co., Ltd., reaction product of isophorone diisocyanate and 2-hydroxyethyl methacrylate (trade name Art Resin SH-300, product of Negami Kogyo Co., Ltd.), reaction of hexamethylene diisocyanate with 2-hydroxyethyl methacrylate Product (Product name Art Resin SH
-400, product of Negami Kogyo Co., Ltd., reaction product of hexamethylene diisocyanate and 2-hydroxypropyl methacrylate (trade name Art Resin SH-420, product of Negami Kogyo Co., Ltd.), hexamethylene diisocyanate and 3-chloro-2
-A reaction product with hydroxypropylmethacrylate (trade name Art Resin SH-440, a product of Negami Kogyo Co., Ltd.), methylenebis (4-cyclohexylisocyanate) and 2-
There are reaction products with hydroxyethyl methacrylate (trade name Art Resin SH-600, product of Negami Kogyo Co., Ltd.), tris (methacryloxyethyl) isocyanate, polyethylene glycol 1000 dimethacrylate, and examples of polyfunctional acrylates are tris ( Acryloxyethyl) isocyanate, pentaerythritol tetraacrylate, pentaerythritol triacrylate,
A polyfunctional acrylate represented by the following structural formula is also suitable.

R ₁ , R ₂ and R ₃ are alkyl groups (trade name: U-108A, product of Shin-Nakamura Chemical Co., Ltd.) As the organic filler in the present invention, polyolefin powder (polyethylene powder, polypropylene powder, etc.), paris acrylate ester Powder (polymethyl acrylate, polyethyl acrylate, etc.), polymethacrylate ester powder (polymethyl methacrylate, polyethyl methacrylate, etc.), methacrylic acid ester copolymer powder (polymethyl methacrylate and polyethyl methacrylate) , Etc.), acrylic acid ester copolymer powder (copolymer of polymethyl acrylate and polyethyl acrylate, etc.), crosslinkable methacrylic acid ester powder (polymethacrylic acid crosslinked with trimethylolpropane trimethacrylate) Methyl), styrene- Tajien copolymer powder, acrylonitrile - styrene copolymer powder, acrylate Lori tolyl - styrene - butadiene copolymer powder include nylon powder, this like may be used alone or in combination. The addition amount is a photopolymerizable compound.
0.1 to 90 parts by weight is preferable for 100 parts by weight.

As the photopolymerization initiator, α-diketone compounds, ketal compounds, anthraquinone compounds, thioxanthone compounds, and benzoin alkyl ether compounds are effective. Specifically, α-diketone compounds are
d, l camphorquinone, benzyl, diacetyl, acenaphthenequinone, and 9,10-phenanthrenequinone are effective. Among these, d, l camphorquinone and benzyl are particularly preferable. Examples of the ketal compound include benzyl dimethyl ketal, benzyl diethyl ketal, benzyl dipropyl ketal, benzyl di (β-phenylethyl) ketal, benzyl di (2-methoxyethyl) ketal, benzyl di (2-ethoxyethyl) ketal, benzyl di (2-methoxyethoxy). Ethyl) ketal, benzyldi (2-ethoxyethoxyethyl) ketal, 4,
4'-Dimethylbenzyldimethyl ketal, 2,2-dimethoxybenzyl diethyl ketal, 4,4'-dichlorobenzyl-diethyl ketal, 4,4'-dichlorobenzyl dipropyl ketal and the like are effective. Among them, benzyl dimethyl ketal, benzyl diethyl ketal, benzyl di (2-methoxyethyl) ketal, and 4,4'-dichlorobenzyl dimethyl ketal are particularly preferable.

Anthraquinone compounds include anthraquinone, 1-
Chloroanthraquinone, 2-Chloroanthraquinone, 1,2-
Benzanthraquinone, 1-hydroxyanthraquinone, 1
-Methylanthraquinone, 2-Ethylanthraquinone, 1-
Bromoanthraquinone is effective. Among them, anthraquinone, 1-chloroanthraquinone and 1,2-benzanthraquinone are particularly preferable. Thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2
-Isopropylthioxanthone, 2-nitrothioxanthone, 2-methylthioxanthone, 2,4-dimethyloxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chloro-7-trifluoromethylthioxanthone, thioxanthone-10 , 10-dioxide, thioxanthone-10-oxide, etc. are effective. Among these, thioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone and 2,4-diisopropylthioxanthone are particularly preferable.

Benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin butyl ether and the like are effective as the benzoin alkyl ether compound. Among them, benzoin butyl ether is particularly preferable.

The above photopolymerization initiators may be used either individually or in combination of two or more. The amount of these photopolymerization initiators to be added is 0.0 with respect to 100 parts by weight of a photopolymerizable compound containing at least one ethylenically unsaturated double bond and solid at room temperature.
It is preferably from 01 to 5 parts by weight. If the compounding amount is less than 0.001 part by weight, the reactivity becomes poor and the curing time becomes long, and the curing depth becomes small. On the other hand, if the blending amount exceeds 5 parts by weight, the surplus catalyst acts as a plasticizer, which reduces the strength of the cured product.

The reducing agent of the present invention reduces the photosensitizer when the reverse sensitizer is in an excited state, but reduces the photosensitizer when the photosensitizer is not excited by active energy rays. The one with the reduction ability that cannot be used is used. The reducing agent may be a primary, secondary or tertiary amine, In which 2, 1, or 0 radicals R, R ', R "may be hydrogen atoms, and one or more radicals R, R', R" may be hydrocarbon radicals, And they can be the same group. The hydrocarbon group may be, for example, an alkyl, cycloalkyl, hydroxyalkyl or aralkyl group. Suitably the groups R, R ', R "may be alkyl groups having 1 to 10 carbon atoms.

Examples of suitable reducing agents in which one or more units R, R ', R "are hydrocarbons include propylamine, n-butylamine, pentylamine, hexylamine, zamethylamine, diethylamine, dipropylamine, di -N-butylamine, dipentylamine, 2-dimethylaminoethanol, trimethylamine, triethylamine, tripropylamine, tri-n-butylamine, tripentylamine, dimethylaminoethylmethacrylate, diethylaminoethylmethacrylate, triethanolamine and long-chain aliphatic amines There is.

Examples of reducing agents containing aromatic groups are N, N'-dimethylaniline, N, N'-dimethyl-p-toluidine, p-tolyldiethanolamine, m-tolyldiethanolamine, N-methyldiphenylamine, 2-dimethyl. Ethyl aminobenzoate, 4-dimethylaminoethyl benzoate, methyl 4-dimethylaminobenzoate, butyl 4-dimethylaminobenzoate, 4
Examples include 2-ethylhexyl dimethylaminobenzoate and isoamyl 4-dimethylaminobenzoate.

Also There is a diamine having the structure of However, n is an integer of 2 or more, and the groups R, R ', R "and R may be the same or different and each is a hydrogen atom or a hydrocarbon group, especially an alkyl group. As the reducing agent in this example, ethylenediamine, It can be trimethylenediamine, tetramethylenediamine, pentamethylenediamine or hexamethylenediamine or N-hydrocarbon radical derivatives thereof, especially N-alkyl derivatives.

Examples of reducing agents in which the element N is part of the ring system are, for example, piperidine and N-hydrocarbon derivatives of piperidine. Other reducing agents include triarylamine, allyl thiaurea, aromatic sulfinates, 5-alkyl- or 5-aryl barbituric acids.

Among these reducing agents, dimethylaminoethyl methacrylate, triethanolamine, methyl 4-dimethylaminobenzoate and ethyl 4-dimethylaminobenzoate are preferable.

The amount of these reducing agents added is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the photopolymerizable compound containing at least one ethylenically unsaturated double bond. Addition amount
If it is less than 0.01 parts by weight, the reactivity is poor and the curing time becomes long, and the curing depth becomes small. Further, if the amount added exceeds 10 parts by weight, the storage stability becomes poor, and the time for technical operation in the normal indoor certification becomes extremely short.

The photopolymerizable clasp pattern composition is preferably preformed into a shape suitable for producing a clasp pattern, and Table 1 shows examples of the shape.

It is important for controlling the maintenance force when the partial denture is attached or detached or when chewing, but its shape is not limited to that shown in Table 1.

〔Example〕

The compositions of the following Examples and Comparative Examples were prepared and prepared, and Experiments 1 to 8 were conducted to confirm the curing of the present invention. The present invention is not limited to the above.

Examples 1-26; Table 2 shows the composition.

Example 27; Table 3 shows its composition.

Comparative Examples 1 to 6; performed to limit the scope of Examples. The composition is shown in Table 2.

Comparative Example 7; This is an example in which an inorganic filler is used instead of the organic filler in the composition of the photopolymerizable clasp pattern composition of the present invention.
The composition is shown in Table 2.

Comparative Example 8: Clasp pattern of commercially available paraffin wax (manufactured by Meta Dental Industry Co., Ltd., trade name: Gie Clasp Pattern) Examples 1-27 and Comparative Examples 1-8 were carried out by the following method.

First, a photopolymerizable solid compound at room temperature containing at least one ethylenically unsaturated 2 polymerization is used as a compound having a melting point (about
(60 ° C to 80 ° C) and melted at a temperature of not less than 60 ° C to 80 ° C, and a suitable amount of a photopolymerization initiator and a reducing agent are added to the liquid, and the mixture is stirred until it is uniformly dissolved. The completely melted product is put in a predetermined amount in a mortar whose temperature can be controlled at about 80 ° C, and an organic filler corresponding to the amount is gradually added and stirred. When the organic filler is uniformly dispersed and mixed, the paste-like material is put into a vacuum degassing machine capable of heating to remove air bubbles. The paste from which air bubbles have been removed is cooled to room temperature, press-molded with a mold designed to have the shape shown in Table 1, and taken out. All the manufacturing processes were performed under a red lamp under the conditions of 100V, 60W, 500L _X or less.

 Next, the effects of the present invention were confirmed in Experiments 1 to 8.

The effects of the present invention are shown in Tables 2 and 3.

Experiment 1 Operability before curing No stickiness and rich flexibility.

Experiment 2 Flexural strength after curing [ISO4049 (25 × 2 × 2m
m)] (Ketal-based and benzoin alkyl ether-based products are manufactured by Jisha Co., Ltd., except that they are irradiated with the product name GC Permakiure UC-I for 20 minutes. Irradiate on both sides for a total of 2 minutes, CHS is 1 mm / min) This value is not necessarily large, but about 200 kg /
If it is cm ² or more, it can be used sufficiently.

Experiment 3 Incineration residue (Incinerate at 600 ° C for 1 hour with auto furnace) Residue must be zero.

Experiment 4 Curing time (Ketal-based and benzoin alkyl ether-based are manufactured by Jantai Co., Ltd., brand name GC Permakiure UC-I is used to judge every 5 seconds by contact with a Vicat needle. It is easy to use if it is in the range of 30 seconds to 1 minute and 30 seconds. If it is faster than 30 seconds, the operation margin may be short, and if it exceeds 1 minute 30 seconds, the sharp curing property of photopolymerization cannot be used.

Experiment 5 Curing Depth (Ketal type and benzoin alkyl ether type are manufactured by Jantai Co., Ltd., trade name GC Permakiure UC-I, irradiated for 20 minutes, and the uncured portion is washed with ethyl alcohol and wiped with gauze.
Other than that, the product is manufactured by Jitoshi Co., Ltd., and the product name is GC Labolite LV-I, which is irradiated for 40 seconds, and the uncured portion is washed with ethyl alcohol and wiped with gauze. ) Since the thickest No. 1 clasp pattern is 3.79 mm,
A hardening depth equal to or greater than this value is required. In addition, depending on the case, it is fully possible that the rest and legs will be about 4 mm, so it is desirable to have a hardening depth of 4 mm or more.

Experiment 6 Clasp production time Time required from surveying of working model to polishing of castings Experiment 7 Whether adhesive is required For example, whether or not Preform Bond from Jitai Co. is required.

Experiment 8 Condition of casting surface Whether surface is rough or not.

Examples 1 to 9 and 11 to 16 and Examples 18 to 26 are examples in which polymethylmethacrylate powder is mixed in a photopolymerizable compound containing at least one ethylenically unsaturated double bond which is solid at room temperature. Example 10 is an example in which polypropylene powder is mixed, and Example 17 is an example in which styrene-butadiene copolymer powder is added. Among them, Example 11,1
Nos. 2,18,19,20 show examples in which the amount of polymethyl methacrylate powder added was changed, and the physical properties were not significantly affected within this range.

The photopolymerization initiators of Examples 1 and 5 to 22 and 24-26 are d, l camphorquinone, and the polymerization initiators of Examples 2, 3, 4, and 23 are 1,2 benzanthraquinone, thioxanthone, and benzoin, respectively. Isobutyl ether and benzyl dimethyl ketal. Among these photopolymerization initiators, 1,2 benzanthraquinone can be sufficiently effective even in a small amount. The reducing agent in Examples 1-4 and 6-26 is dimethylaminoethylmethacrylate, and the reducing agent in Example 5 is methyl 4-dimethylaminobenzoate. Examples 13 and 25 show examples in which the amount of the photopolymerization initiator d, l camphorquinone added was small, and Example 14 showed a large amount. If the addition amount of d, l camphorquinone is small, the curing time will be delayed,
If the number is large, the speed tends to be high, but if it is within the scope of the claims, there is no problem in use. Examples 15 and 26 show examples in which the reducing agent dimethylaminoethyl methacrylate was added in a small amount, and Example 16 showed a large amount. If the addition amount of dimethylaminoethyl methacrylate is small, the curing time will be delayed, and if the addition amount is large, the curing time will be fast, but if it is within the scope of the claims, there is no problem in use.

Examples 1 to 5 and 10 to 20,23,25,26 are examples in which a polyfunctional acrylate is used among the photopolymerizable compounds that contain at least one ethylenically unsaturated double bond and are solid at room temperature. Examples 6 and 7 are examples using polyfunctional methacrylate. Further, Examples 8, 9, and 24 are examples in which polyfunctional acrylate and methacrylate were mixed. Example 21 is an example using a monofunctional methacrylate, and Example 22 is an example using a monofunctional acrylate.

Example 27 contains at least one ethylenically unsaturated double bond.
This is an example in which two kinds of polyfunctional methacrylates are mixed and used as a photopolymerizable compound containing individual and solid at room temperature, and polymethylmethacrylate powder cross-linked with trimethylolpropane trimethacrylate is used as a filler. The state of the casting surface using this filler becomes particularly excellent. Further, the curing depth was about twice as large as that in the example, and it is shown that the polymerization is sufficiently advanced.

Comparative Examples 1 and 4 are examples in which the addition amount of polymethylmethacrylate powder as an organic filler deviates from the preferable range. However, when the addition amount deviates to the smaller one as in Comparative Example 1, the operability is deteriorated. It has a bad characteristic that it is sticky,
If it deviates to a larger number as in Comparative Example 4, the flexibility such as paraffin wax is lost and the product becomes brittle. Comparative Example 2 is an example in which the addition amount of d, l camphorquinone as a photopolymerization initiator and Comparative Example 3 were both deviated from the preferable range in the addition amount of dimethylaminoethyl methacrylate as a reducing agent. It can be seen that the polymerization is insufficient, the bending strength is low, the curing time is long, and the curing depth is small. Comparative Example 5 is d,
Comparative Example 6 is an example in which the amount of l-camphorquinone added deviates to the one in which the amount of dimethylaminoethyl methacrylate added is large, and the curing is so fast that a sufficient operating margin cannot be obtained and d, l In the case where the amount of non-added material deviated to the larger one, a decrease in bending strength was observed. It is considered that this is because the surplus catalyst worked as a plasticizer to reduce the strength. Comparative Example 7 is an example in which an inorganic filler is added as a filler and is similar to the conventional compounded resin formulation. However, since the filler is an inorganic substance, the incineration residue does not become zero and it has no function of casting the clasp at all.

Comparative Example 8 is an example using a clasp pattern of a paraffin wax, which has been conventionally performed. This is an example of using a GC clasp pattern manufactured by Jiji Co., but the clasp production time is about 8 hours because the investment method is performed for each mold, replacing the working model with the investment material for the model and conducting surveying and casting. However, it takes about 4 hours longer than the case where the photopolymerizable clasp pattern composition of the present invention is used.
Furthermore, in order to use the clasp pattern of the paraffin wax, an adhesive agent (for example, Preform Bond manufactured by Jiji Co., Ltd.) is required to adhere to the investment material for the model. Further, the condition of the casting surface may be adversely affected depending on the incineration condition of wax and the type of investment material.

[Effects of the Invention] The clasp pattern of the paraffin wax used in the past is not elastically deformed at all and cannot be removed from the working model. Is being carried out. Therefore, the clasp manufacturing process is complicated and requires a long time, and the material cost is also great. Further, an adhesive is required to bond the clasp pattern of the paraffin wax to the investment material for the model or plaster. Further, in the clasp pattern of the paraffin wax, cracks in the investment material and roughening of the inner surface of the investment material occur due to rapid pressurization due to expansion during incineration.

The clasp pattern made of the photopolymerizable resin composition of the present invention is a fundamental solution to these drawbacks. At the stage of adhering and forming the clasp pattern on the working model for making the clasp pattern, the clasp pattern is as flexible as the conventional paraffin wax and can be freely formed without a special heating device, and the clasp pattern is adhered to the working model. By irradiating the active energy ray such as a plastic ray immediately after the completion of molding, the clasp pattern is hardened, and the clasp pattern is changed to one having sufficient strength to withstand the strain when passing from the undercut portion to the maximum protuberance portion. is there.

This makes it possible to remove the clasp pattern from the working model, which was not possible with the clasp pattern of paraffin wax. Therefore, it is no longer necessary to perform the so-called investment method for each type of so-called model investment material. Therefore, the clasp pattern manufacturing process, which required about 8 hours in the past, was shortened to about 4 hours, and the cost of the impression material and investment material for the model that had been used conventionally was reduced accordingly. Further, the photopolymerizable resin composition obtained according to the present invention has a good familiarity with a work model and is appropriately bonded, and can be easily removed after curing. Therefore, a special adhesive is not required, and it is possible to prevent clogging due to the thickness of the adhesive film as in the conventional case and to make a clasp with high precision. Further, since there is no need to press the fingers against each other, the adverse effect of the peeling of the investment material particles on the surface properties of the maintenance tooth and the casting clasp is completely eliminated. Further, the photopolymerizable resin composition obtained by the present invention is a crystalline polymer, which gradually softens without boiling even when heated, then carbonizes and finally becomes carbon dioxide and water. There is an advantage that a good clasp of the casting surface can be obtained without causing cracks or roughening of the inner surface of the investment material.

The composition obtained according to the present invention can be used not only for clasp patterns, but also for inlay patterns, lingual bar patterns, paratalbar patterns, skeleton patterns, casting floor patterns, crown bridging patterns, and other casting patterns. I can.

Claims (10)

[Claims] 1. A photopolymerizable compound containing at least one ethylenically unsaturated double bond; b) an organic filler; c) a photopolymerization initiator; and d) a reducing agent. Photopolymerizable resin composition for class pattern production. 2. At least one ethylenically unsaturated double bond.
The photopolymerizable resin composition for producing a clasp pattern according to claim 1, which is a photopolymerizable compound contained therein and is a solid at room temperature. 3. At least one ethylenically unsaturated double bond.
The photopolymerizable resin composition for producing a clasp pattern according to claim 1 or 2, wherein the photopolymerizable compound contained therein is a monofunctional methacrylate. 4. At least one ethylenically unsaturated double bond.
The photopolymerizable resin composition for producing a clasp pattern according to claim 1 or 2, wherein the photopolymerizable compound contained therein is a polyfunctional methacrylate. 5. At least one ethylenically unsaturated double bond.
The photopolymerizable resin composition for producing a clasp pattern according to claim 1 or 2, wherein the photopolymerizable compound contained therein is a monofunctional acrylate. 6. At least one ethylenically unsaturated double bond.
The photopolymerizable resin composition for producing a clasp pattern according to claim 1 or 2, wherein the photopolymerizable compound contained therein is a polyfunctional acrylate. 7. A compounding amount of an organic filler is 0.1 to 90 parts by weight with respect to 100 parts by weight of a photopolymerizable compound containing at least one ethylenically unsaturated double bond. Item 7. A photopolymerizable resin composition for producing a clasp pattern according to any one of items 1 to 6. 8. A photopolymerization initiator is an α-diketone compound,
The clasp according to any one of claims 1 to 7, which is at least one of a ketal compound, an anthraquinone compound, a thioxanthone compound, a benzoin alkyl ether compound, and a derivative thereof. A photopolymerizable resin composition for pattern formation. 9. A compounding amount of a photopolymerization initiator is 0.001 to 5 parts by weight with respect to 100 parts by weight of a photopolymerizable compound containing at least one ethylenically unsaturated double bond. The photopolymerizable resin composition for producing a clasp pattern according to any one of items 1 to 8. 10. A photopolymerizable compound 100 containing at least one ethylenically unsaturated double bond in a reducing agent content.
The photopolymerizable resin composition for producing a clasp pattern according to any one of claims 1 to 9, which is 0.01 to 10 parts by weight with respect to parts by weight.