JP2021171894A - Polyurea composite abrasive material for grinding and polishing denture material and method for manufacture thereof - Google Patents

Abstract

To provide a polyurea composite abrasive material for grinding and polishing denture material which enables precise grinding/polishing of a denture material by a ductile mode and which is also excellent in durability against sterilization treatment, and a method for manufacture of the same.SOLUTION: A polyurea composite abrasive material for grinding and polishing denture material is produced in such a manner that a mixture of a polyamine compound, a trivalent or higher polyol compound, a diisocyanate compound, a trivalent or higher polyisocyanate compound, and abrasive grains is polymerized and cured. A method for manufacturing the polyurea composite abrasive material for grinding and polishing denture material includes a process in which a mixed liquid of an aromatic polyamine oligomer, an aromatic diamine compound, a trivalent or higher polyol compound and an organic solvent, abrasive grains, a diisocyanate compound, and a trivalent or higher polyisocyanate compound are mixed, and the mixture is polymerized and cured.SELECTED DRAWING: None

Description

The present invention relates to a polyurea composite grindstone material suitable for grinding and polishing a denture material, and a method for producing the same.

Denture dentures are dental materials that make up for lost teeth, and are ground and polished with a grindstone to achieve a comfortable feel. As the material of the artificial tooth, a metal material such as cobalt-chromium alloy, titanium, titanium alloy; a ceramic material such as zirconia; a composite material of glass or ceramics and resin such as a hybrid resin or a composite resin is used, and a gingival material is also used. Resin materials such as acrylic resin and polyamide are used as the material.
The grindstone used for grinding and polishing denture materials is required to have biosafety (prevention of harm) that can be used in the oral cavity, and also enhances the usability, aesthetics, and plaque prevention of dentures. In addition, various functionalities that can realize sufficient smoothness, glossiness, etc. even on a finished surface having a more complicated shape are required. And these demands are increasing year by year.

As for industrial materials, polyurea composite abrasives in which abrasive grains and polyurea are compounded have been proposed from rough grinding to precision polishing (for example, Patent Documents 1 to 3).

Patent No. 6489465 Patent No. 4357173 Patent No. 3921056

The most effective method for grinding and polishing a prosthetic tooth material having a complicated shape is to manually grind and polish an electric grinding machine equipped with a shafted grindstone at a constant rotation speed. For example, in the manual grinding and polishing of zirconia denture materials, a grindstone using vitrify or phenol resin is used as a binder. However, these grindstones are hard and brittle. Therefore, the grinding / polishing is performed in the brittle mode (a mode in which cracks are generated in the denture material and the cracks are indexed), and the finish is very rough.
After grinding and polishing the denture material in such a brittle mode, polishing with a grindstone using a rubber binder such as chloroprene or silicone is performed in order to obtain a more precise finished surface. However, rubber is soft and has a weak adhesive force to abrasive grains (fixing force of abrasive grains). Therefore, it is difficult to finish the rough finished surface after grinding and polishing in the brittle mode to the highly precision polished surface required for denture materials. Therefore, the surface is also finished with a buff material in which abrasive grains such as diamond are embedded in a base material such as non-woven fabric. However, with this surface finish, even if a polished surface having a certain degree of luster is obtained, the high-precision polished surface required for a denture material has not been realized.
Therefore, a grindstone capable of precisely grinding and polishing a rough surface in the brittle mode in a ductile mode (a mode in which the surface is gradually ground like a plane) so as to satisfy the above-mentioned characteristics required for a denture material is available. It has been demanded.

The present inventor has focused on the fact that the polyurea composite abrasive (grinding stone) as described in Patent Documents 1 to 3 has both hardness and rubber elasticity, and tried to use it for grinding and polishing artificial tooth materials. rice field. As a result, by using the polyurea composite abrasive, it is possible to grind and polish the denture material in the ductile mode, and the rough surface in the brittle mode is sufficiently smooth and the precision polished surface has excellent gloss. I found that I could finish it.
On the other hand, new issues have become clear. That is, the grindstone applied to the denture material is reused after being used by being subjected to a high-temperature and high-pressure sterilization treatment by an autoclave. However, it has been found that the polyurea composite abrasive cannot be reused in a state where the initial performance is maintained because the polyurea is decomposed or denatured by this sterilization treatment. Although the cause of this is not clear, the sterilization process at high temperature and high pressure cleaves the bullet cross-linking point due to the reaction between the urea bond and the isocyanate group, breaks the three-dimensional structure and changes it to a two-dimensional structure, and hard blocks and aggregation. It is considered that one of the causes is that the pseudo-crosslink points such as blocks are also cleaved and the physical properties of polyurea are significantly changed.

An object of the present invention is to provide a polyurea composite grindstone material for grinding and polishing a denture material, which enables precise grinding and polishing of the denture material in a ductile mode and has excellent durability against sterilization. Another object of the present invention is to provide a method for producing a polyurea composite grindstone material for grinding and polishing a denture material suitable for obtaining the above-mentioned grindstone material.

The present inventor has conducted extensive research in view of the above problems. As a result, in the preparation of the polyurea composite abrasive, which is a composite material of abrasive grains and polyurea, a polyisocyanate compound having a valence of 3 or more is used as a raw material for the polyurea, and a polyol having a valence of 3 or more is further used. By using the compound, a strong crosslinked structure having a certain degree of flexibility is formed by the bond between the polyisocyanate component and the polyol component in the formed polyurea structure, and the polyurea structure is formed under high temperature and high pressure. We have found that sterilization durability is effectively enhanced. That is, it has been found that the obtained polyurea composite grindstone material has the hardness and rubber elasticity peculiar to the polyurea resin, but also has excellent sterilization durability under high temperature and high pressure, and can solve the above problems.
Based on these findings, the present invention has been further studied and completed.

式中、Ｒは、ｎ価の数平均分子量２００以上のポリアルキレンポリオール、ポリアルキレンエーテルポリオール又はポリアルキレンエステルポリオールの残基を表わし、ｎは２又は３を表す。但し、当該ポリアルキレン中に不飽和結合を含んでいてもよい。
〔５〕
上記芳香族ジアミン化合物が、トリメチレン−ビス（４−アミノベンゾエート）［別名：１，３−プロパンジオール−ビス（ｐ−アミノベンゾエート）］、４−クロロ−３，５−ジアミノベンゾイックアシッドイソブチルエステル、４，４’−ジアミノジフェニルメタン−３，３’−ジカルボン酸ジエチルエステル、及び２，２’、３，３’−テトラクロロ−４，４’−ジアミノジフェニルメタンの１種又は２種以上を含む、〔２〕〜〔４〕のいずれか１つに記載の義歯材研削・研磨用ポリ尿素複合砥石材。
〔６〕
上記の３価以上のポリオール化合物が、１分子中に３〜６個の水酸基を有し分子量が９２〜６００であるポリオール化合物を含む、〔１〕〜〔５〕のいずれか１つに記載の義歯材研削・研磨用ポリ尿素複合砥石材。
〔７〕
上記の３価以上のポリオール化合物が、グリセリン、トリメチロールプロパン、トリエタノールアミン、ヘキサントリオール、ペンタエリスリトール、ジグリセリン、及びメチルグルコシドの１種又は２種以上を含む、〔１〕〜〔６〕のいずれか１つに記載の義歯材研削・研磨用ポリ尿素複合砥石材。
〔８〕
上記ジイソシアネート化合物が、ジフェニルメタンジイソシアネートを含む、〔１〕〜〔７〕のいずれか１つに記載の義歯材研削・研磨用ポリ尿素複合砥石材。
〔９〕
上記の３価以上のポリイソシアネート化合物が、ポリメリックジフェニルメタンジイソシアネート由来のもの、３価以上のジフェニルメタンジイソシアネートプレポリマー、及び、１，３，５−トリス（６−イソシアナートヘキサ−１−イル）１，３，５−トリアジン−２，４，６（１Ｈ，３Ｈ，５Ｈ）−トリオンの少なくとも１種を含む、〔１〕〜〔８〕のいずれか１つに記載の義歯材研削・研磨用ポリ尿素複合砥石材。
〔１０〕
上記混合物中、ジイソシアネート化合物と３価以上のポリイソシアネート化合物の各含有量の合計に占めるジイソシアネート化合物の含有量の割合が４０質量％以上である、〔１〕〜〔９〕のいずれか１つに記載の義歯材研削・研磨用ポリ尿素複合砥石材。
〔１１〕
上記ジフェニルメタンジイソシアネート化合物がカルボジイミド変性ジフェニルメタンジイソシアネートを含む、〔１０〕に記載の義歯材研削・研磨用ポリ尿素複合砥石材。
〔１２〕
上記混合物中、上記ポリアミン化合物の含有量１００質量部に対し、上記の３価以上のポリオール化合物の含有量が２〜１７質量部である、〔１〕〜〔１１〕のいずれか１つに記載の義歯材研削・研磨用ポリ尿素複合砥石材。
〔１３〕
上記ポリ尿素複合砥石材の密度が０．４〜３．５ｇ／ｃｍ^３である、〔１〕〜〔１２〕のいずれか１つに記載の義歯材研削・研磨用ポリ尿素複合砥石材。
〔１４〕芳香族ポリアミンオリゴマーと芳香族ジアミン化合物と３価以上のポリオール化合物と有機溶媒との混合液と、砥粒と、ジイソシアネート化合物と、３価以上のポリイソシアネート化合物とを混合し、この混合物を重合硬化することを含む、義歯材研削・研磨用ポリ尿素複合砥石材の製造方法。 The above-mentioned problems of the present invention have been solved by the following means.
[1]
A polyurea composite grindstone material for grinding and polishing artificial tooth materials, which is obtained by polymerizing and curing a mixture containing a polyamine compound, a trivalent or higher-valent polyol compound, a diisocyanate compound, a trivalent or higher-valent polyisocyanate compound, and abrasive grains.
[2]
The polyurea composite grindstone material for grinding and polishing a denture material according to [1], wherein the polyamine compound contains any of the following (a) to (d).
(A) Aromatic polyamine oligomers (b) Aromatic polyamine oligomers and aromatic diamine compounds (c) aliphatic polyamine oligomers, aromatic polyamine oligomers and aromatic diamine compounds (d) aliphatic polyamine oligomers and aromatic polyamine oligomers [3] ]
The artificial tooth material grinding according to [2], wherein the polyamine compound contains an aromatic polyamine oligomer and an aromatic diamine compound, and the ratio of the aromatic diamine compound to the polyamine compound in the mixture is 40% by mass or less. Polyurea compound grindstone for polishing.
[4]
The polyurea composite grindstone material for grinding and polishing a denture material according to [2] or [3], wherein the aromatic polyamine oligomer contains a polyamine oligomer represented by the following formula (I).

In the formula, R represents a residue of a polyalkylene polyol, a polyalkylene ether polyol or a polyalkylene ester polyol having an n-valent number average molecular weight of 200 or more, and n represents 2 or 3. However, the polyalkylene may contain an unsaturated bond.
[5]
The aromatic diamine compound is trimethylene-bis (4-aminobenzoate) [also known as 1,3-propanediol-bis (p-aminobenzoate)], 4-chloro-3,5-diaminobenzoic acid isobutyl ester, Includes one or more of 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid diethyl ester, and 2,2', 3,3'-tetrachloro-4,4'-diaminodiphenylmethane. 2] The polyurea composite abrasive for grinding and polishing the artificial tooth material according to any one of [4].
[6]
4. The above-mentioned one of [1] to [5], wherein the above-mentioned trivalent or higher-valent polyol compound contains a polyol compound having 3 to 6 hydroxyl groups in one molecule and a molecular weight of 92 to 600. Polyurea compound grindstone for grinding and polishing of artificial tooth material.
[7]
[1] to [6], wherein the trivalent or higher-valent polyol compound contains one or more of glycerin, trimethylolpropane, triethanolamine, hexanetriol, pentaerythritol, diglycerin, and methylglucoside. The polyurea composite abrasive for grinding and polishing of artificial tooth material according to any one of them.
[8]
The polyurea composite grindstone material for grinding and polishing a denture material according to any one of [1] to [7], wherein the diisocyanate compound contains diphenylmethane diisocyanate.
[9]
The above trivalent or higher polyisocyanate compounds are derived from polypeptide diphenylmethane diisocyanate, trivalent or higher diphenylmethane diisocyanate prepolymer, and 1,3,5-tris (6-isosyanatohex-1-yl) 1,3. , 5-Triazine-2,4,6 (1H, 3H, 5H) -The polyurea composite for grinding and polishing artificial tooth material according to any one of [1] to [8], which contains at least one of trions. Abrasive material.
[10]
In any one of [1] to [9], the ratio of the content of the diisocyanate compound to the total content of the diisocyanate compound and the trivalent or higher polyisocyanate compound in the above mixture is 40% by mass or more. The polyurea composite grindstone material for grinding and polishing the prosthetic tooth material described.
[11]
The polyurea composite grindstone material for grinding and polishing a prosthetic tooth material according to [10], wherein the diphenylmethane diisocyanate compound contains a carbodiimide-modified diphenylmethane diisocyanate.
[12]
The description in any one of [1] to [11], wherein the content of the trivalent or higher polyol compound is 2 to 17 parts by mass with respect to 100 parts by mass of the polyamine compound in the mixture. Polyurea composite grindstone material for grinding and polishing of artificial tooth material.
[13]
The polyurea composite grindstone material for grinding and polishing a denture material according to any one of [1] to [12], wherein the density of the polyurea composite grindstone material is 0.4 to 3.5 g / cm ^3.
[14] A mixture of an aromatic polyamine oligomer, an aromatic diamine compound, a trivalent or higher polyol compound, and an organic solvent, abrasive grains, a diisocyanate compound, and a trivalent or higher polyisocyanate compound are mixed, and the mixture thereof. A method for producing a polyurea composite grindstone for grinding and polishing a prosthetic tooth material, which comprises polymerizing and curing the material.

The polyurea composite grindstone material for grinding and polishing denture materials of the present invention enables precise grinding and polishing of denture materials in a ductile mode, and has excellent durability against sterilization. Further, the method for producing a polyurea composite grindstone material for grinding and polishing a prosthetic tooth material of the present invention is a suitable production method for obtaining a polyurea composite grindstone material for grinding and polishing a prosthetic tooth material of the present invention.

A preferred embodiment of the polyurea composite grindstone material for grinding and polishing the denture material of the present invention (hereinafter, also referred to as the grindstone material of the present invention) will be described.
The grindstone material of the present invention is composed of a polyurea resin having a specific constituent component as a binder (binding material) and abrasive grains dispersed in the polyurea resin. The grindstone material of the present invention is suitable for precisely grinding and polishing a dental denture material. The term "denture material" in the present invention means to include a dental gingival material.

The grindstone material of the present invention is a grindstone material obtained by polymerizing and curing a mixture containing a polyamine compound, a trivalent or higher-valent polyol compound, a diisocyanate compound, a trivalent or higher-valent polyisocyanate compound, and abrasive grains. That is, the binder (binding material) constituting the grindstone material of the present invention is a polymer cured product of at least a polyamine compound, a trivalent or higher polyol compound, a diisocyanate compound, and a trivalent or higher polyisocyanate compound.

[Polyamine compound]
The polyamine compound is not particularly limited as long as it reacts with the diisocyanate compound and a trivalent or higher valent polyisocyanate compound to polymerize to form polyurea. The amino group contained in the polyamine compound is preferably an unsubstituted amino group. The polyamine compound preferably contains any of the following (a) to (d), and more preferably any of the following (a) to (d).
(A) Aromatic polyamine oligomers (b) Aromatic polyamine oligomers and aromatic diamine compounds (c) aliphatic polyamine oligomers, aromatic polyamine oligomers and aromatic diamine compounds (d) aliphatic polyamine oligomers and aromatic polyamine oligomers

In the above (b) and (c), the ratio of the aromatic diamine compound is not particularly limited. As the proportion of the aromatic diamine compound increases, the hardness, tear strength, adhesive strength, and softening point of the obtained polyurea increase. As a result, the polishing power of the grindstone material is increased, the surface becomes rough, and the durability is improved. On the contrary, when the ratio of the aromatic diamine compound is reduced, the hardness, tear strength and adhesive strength of the obtained polyurea are lowered. As a result, the polishing power of the grindstone material is reduced, the surface roughness is reduced, and the releasability of the abrasive grains from the grindstone material is improved. That is, the ratio of the aromatic diamine compound is appropriately adjusted according to the desired function of the grindstone material.

The proportion of the aromatic polyamine oligomer is not particularly limited in the form containing any of the above (a), (b), (c) and (d). As the proportion of aromatic polyamine oligomers increases, the hardness of the resulting polyurea decreases, elongates, and rubber elasticity increases. Therefore, although the polishing power of the obtained grindstone material is reduced, the surface roughness obtained is small and a mirror surface can be easily obtained. On the contrary, when the ratio of the aromatic polyamine oligomer is reduced, the obtained polyurea has a high hardness, a small elongation, a low rubber elasticity, and a strong tendency to be resinified. As a result, the grindability of the grindstone material is improved and the surface roughness is increased. In addition, the detachability of the abrasive grains is reduced and the durability is increased.
That is, the ratio of the aromatic polyamine oligomer is appropriately adjusted according to the desired function of the grindstone material.

In the form containing either (b) or (c), the ratio of the aromatic diamine compound to the total polyamine compound contained in the mixture is preferably 40% by mass or less, preferably 2 to 35% by mass. It is more preferably%, and further preferably 2 to 30% by mass.

The polyamine compound contained in the mixture preferably contains the above (b) or (c). When the polyamine compound contains the above (b), the proportion of (b) in the polyamine compound is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and 90% by mass or more. Is particularly preferable.
When the polyamine compound contains the above (c), the proportion of (c) in the polyamine compound is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and 90% by mass or more. Is particularly preferable.
The polyamine compound is more preferably (b) or (c), and more preferably (b).
When the polyamine compound contains the above (b) or (c), the ratio of the aromatic diamine compound to the total amount of the polyamine compound contained in the mixture is preferably 40% by mass or less, preferably 2 to 35% by mass. It is more preferably%, and further preferably 2 to 30% by mass.

In the form in which the polyamine compound contains any of the above (c) and (d), the proportion of the aliphatic polyamine oligomer is appropriately adjusted according to the desired function of the abrasive.
In the form in which the polyamine compound contains any of the above (c) and (d), the ratio of the above aliphatic polyamine oligomer to the total amount of the above polyamine compound contained in the above mixture is preferably 3 to 20% by mass, and 3 to 3 to 20% by mass. 10% by mass is more preferable, and 3 to 7% by mass is also preferable. In this case, the polyamine compound is preferably (c).

The aromatic polyamine oligomer preferably contains one or more compounds represented by the following formula (I). The proportion of the compound represented by the following formula (I) in the aromatic polyamine oligomer is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, further preferably 80 to 100% by mass, and 90 to 100% by mass. % Is particularly preferable. Among them, the aromatic polyamine oligomer that can be used in the present invention is more preferably a compound represented by the following formula (I).

In the formula (I), R is a residue of a polyalkylene polyol, a polyalkylene ether polyol or a polyalkylene ester polyol having an n-valent number average molecular weight of 200 or more (that is, a polyalkylene polyol having a number average molecular weight of 200 or more, a number average molecular weight). It has a structure in which n hydroxyl groups or hydrogen atoms are removed from 200 or more polyalkylene ether polyols or polyalkylene ester polyols having a number average molecular weight of 200 or more, and the site from which the hydroxyl groups or hydrogen atoms are removed is defined as a connecting site. Represents the n-valent group). n represents 2 or 3 and is preferably 2. However, the polyalkylene may contain an unsaturated bond. Moreover, it is preferable that each of the above polyols is a diol.
The number average molecular weight of the above polyalkylene polyol, polyalkylene ether polyol or polyalkylene ester polyol is preferably 200 to 2000, more preferably 600 to 2000, and even more preferably 1000 to 2000.
In the present specification, the number average molecular weight can be measured by quantification of the hydroxyl group of the molecular terminal group or by gel permeation chromatography (GPC).

R is more preferably a polyalkylene polyol having an n-valent number average molecular weight of 200 or more or a polyalkylene ether polyol, and further preferably a polyalkylene ether polyol having an n-valent number average molecular weight of 200 or more.

The aromatic polyamine oligomer represented by the above formula (I) is generally obtained by reacting a polyalkylene polyol, a polyalkylene ether polyol or a polyalkylene ester polyol having a number average molecular weight of 200 or more with a paranitrobenzoic acid chloride, and then forming a nitro group. It can be synthesized by reducing it. It can also be obtained by reacting a polyalkylene polyol, a polyalkylene ether polyol or a polyalkylene ester polyol having a number average molecular weight of 200 or more with an aminobenzoic acid alkyl ester.
Examples of the polyalkylene polyol, polyalkylene ether polyol, or polyalkylene ester polyol having a number average molecular weight of 200 or more used in the above reaction include polytetramethylene ether glycol, polypropylene ether glycol, glycol which is a copolymer of propylene oxide and ethylene oxide, and the like. Polyether polyols, polyethylene adipate polyols, polybutylene adipate polyols, ε-caprolactones, lactone-based polyester polyols derived from γ-butyrolactone, polyester polyols such as adipate-based polyols obtained by the reaction of 3-methylpentanediol with adipic acid, Examples thereof include polyalkylene polyols such as polybutadiene-based polyols.

The terminal group of the aromatic polyamine oligomer is generally an amino group, but in some cases, a part of the terminal of the oligomer to be used may remain as a hydroxyl group, or the oligomer to be used may have a partial terminal group. Both ends of a part may remain as hydroxyl groups. Further, in some cases, an amide group may be contained in a part of the main chain.
The aromatic polyamine oligomer is available as a commercial product. As the above-mentioned polyol, for example, as aromatic polyamine oligomers made from polytetramethylene ether glycol (PTMEG), Versalink P250 (polyol average molecular weight 250) and Versalink P650 (polyol average molecular weight 650) commercially available from Ebony Industry Co., Ltd. ), Versalink P1000 (polyol average molecular weight 1000), Versalink P2000 (polyol average molecular weight 2000) (all are trade names). In addition, Erasmer 250P (average molecular weight 250), Erasmer 650P (average molecular weight 650), Erasmer 1000P (average molecular weight 1000), Porea SL-100A (average molecular weight 1000) (all of which are commercially available from Kumiai Chemical Industry Co., Ltd.) , Product name). These aromatic polyamine oligomers can be used alone or in combination of two or more. All of these aromatic polyamine oligomers are more preferable as raw materials for dental grindstone materials from the viewpoint of safety to the living body.

The aromatic diamine compound is not particularly limited. Specific examples of the aromatic diamine compound can be mentioned below.
Trimethylene-bis (4-aminobenzoate),
4-Chloro-3,5-Diamine Benzoic Acid Isobutyl Ester,
4,4'-Diaminodiphenylmethane-3,3'-dicarboxylic acid diethyl ester,
2,2', 3,3'-tetrachloro-4,4'-diaminodiphenylmethane,
4,4'-Methylenebis (2-chloroaniline),
4,4'-Methylenebis (2,5-dichloroaniline),
4,4'-Methylenebis (Methylanthraniate),
3,5-Dimethylthio-2,4-Toluenediamine,
3,5-Dimethylthio-2,6-Toluenediamine,
1,2-bis (2-aminophenylthio) ethane,

From the viewpoint of further enhancing the safety to the living body, the aromatic diamine compounds are trimethylene-bis (4-aminobenzoate), 4-chloro-3,5-diaminebenzoic acid isobutyl ester, and 4,4'-diaminodiphenylmethane-. More preferably, it is selected from 3,3'-dicarboxylic acid diethyl ester and 2,2', 3,3'-tetrachloro-4,4'-diaminodiphenylmethane.

The aromatic diamine compound may contain one or more of the above-exemplified aromatic diamine compounds, but it is preferable to include one of the above-exemplified aromatic diamine compounds from the viewpoint of aggregate block forming property.

The above aliphatic polyamine oligomer is not particularly limited. The aliphatic polyamine oligomer preferably contains one or more compounds represented by any of the following formulas (II) to (IV). The ratio of the total amount of the compound represented by any of the following formulas (II) to (IV) to the total amount of the aliphatic polyamine oligomer in the mixture is preferably 50 to 100% by mass, more preferably 70 to 100% by mass. Preferably, 80 to 100% by mass is more preferable, and 90 to 100% by mass is particularly preferable. Further, it is more preferable that all of the aliphatic polyamine compounds in the above mixture are compounds represented by any of the following formulas (II) to (IV).

H ₂ N-CH (CH ₃ ) -CH _2- R ^2- NH ₂ (II)

In formula (II), R ² is-[O-CH ₂ -CH (CH ₃ )] _p -or-[O-CH (CH ₃ ) -CH ₂ ] _q- [O-CH _{2-CH. 2} ] _r − [O-CH ₂ -CH (CH ₃ )] It is a divalent group represented by _{s −.} P to s indicating the number of repeating units are all 1 or more. p is preferably 1 to 68, more preferably 5 to 33. q + s is 2 or more, preferably 3.6 to 6.0. r is preferably 9 to 38.7, more preferably 12 to 38.7.

_{H 2 N- [O-CH (} CH 3) -CH 2 ] _{t - [O-CH 2 -CH} 2 -CH 2 -CH 2] u - _{[O-CH 2 -CH (CH 3} ) ] _v -NH ₂ (III)

In formula (III), t to v indicating the number of repeating units are all 1 or more. u is preferably 9 to 17, more preferably 11 to 17. t + v is 6 or more, preferably 6 to 24.

In formula (IV), Ra represents ^a hydrogen atom or an ethyl group. W indicating the number of repeating units is 1 or more independently, and the total of 3 ws is 5 or more. The total of the three ws is preferably 5 to 85, more preferably 5 to 50.
x is 0 or 1. When ^Ra is a hydrogen atom, x is 0, and when ^Ra is an ethyl group, x is 1.

The number average molecular weight of the aliphatic polyamine oligomer that can be used in the present invention is preferably 200 to 5000, more preferably 400 to 5000, and even more preferably 2000 to 5000.

The aliphatic polyamine oligomers represented by the above formulas (II) and (III) can be obtained by ring-opening polymerization of propylene oxide on polyethylene glycol, trimethylolpropane and glycerin, and amination by ammonolysis of the terminal group.
Aliphatic polyamine oligomers represented by the above formulas (II) and (III) are also commercially available. Examples of the compound of the above formula (II) include Jeffamine D400 (number average molecular weight 400), Jeffamine D2000 (number average molecular weight 2000), and Jeffamine ED-900 (number average molecular weight 900) commercially available from San Techno Chemical Co., Ltd. ), Jeffamine ED2003 (number average molecular weight 2000) can be used. Examples of the compound of the above formula (III) include Jeffamine T-403 (number average molecular weight 440), Jeffamine T-3000 (number average molecular weight 3000), and Jeffamine T-, which are commercially available from San Techno Chemical Co., Ltd. 5000 (number average molecular weight 5000) can be used.

[Trivalent or higher polyol compound]
The above-mentioned trivalent or higher-valent polyol compound is not particularly limited as long as it is a compound having three or more hydroxyl groups in one molecule. The trivalent or higher valent polyol compound contained in the mixture has 3 or more, preferably 3 to 6 hydroxyl groups in one molecule, and has a molecular weight of 92 to 600, preferably 92 to 400, more preferably. Preferably contains 92-300 polyol compounds. In a more preferable form, all of the polyol compounds contained in the mixture have 3 or more, preferably 3 to 6 hydroxyl groups in one molecule, and have a molecular weight of 92 to 600, preferably 92 to 400. More preferably, it is in the form of a polyol compound of 92 to 300.

Specific examples of the above-mentioned trivalent or higher valent polyol compound include the following compounds.

Glycerin, trimethylolpropane, triethanolamine, hexanetriol, pentaerythritol, diglycerin, methylglucoside, trimethylolethane, triglycerin, dipentaerythritol, sorbitol, mannitol, propanetriol, butanetriol, trimethylolethane, etc.

Further, a polyalkylene ether polyol obtained by ring-opening polymerization in which the above compound is used as an initiator and propylene oxide or ethylene oxide or a mixture thereof is mixed is also preferable. The molecular weight of this polyalkylene ether polyol is preferably 600 or less.

From the viewpoint of further enhancing the safety to the living body, the preferred polyol compound is a compound selected from glycerin, trimethylolpropane, triethanolamine, hexanetriol, pentaerythritol, diglycerin, and methylglucoside.

In the mixture, one or more of the above-exemplified polyol compounds can be used. The ratio of one or more of the above-exemplified polyol compounds to the total of the above trivalent or higher valent polyol compounds in the mixture is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and 80 to 100. The mass% is more preferable, and 90 to 100% by mass is particularly preferable. It is more preferable that all of the trivalent or higher valent polyol compounds in the mixture are one or more of the above-exemplified polyol compounds.

In the mixture, the content of the trivalent or higher polyol compound is preferably 2 to 17 parts by mass, more preferably 2.5 to 15 parts by mass, based on 100 parts by mass of the polyamine compound. More preferably, it is 3 to 12 parts by mass.

[Diisocyanate compound]
The type of the diisocyanate compound is not particularly limited. For example, diphenylmethane diisocyanate (MDI), cyclohexanediisocyanate (CHDI), isophorone diisocyanate (IPDI), naphthalenediocyanate (NDI), 3,3'-dimethyl-4,4'-diphenylene diisocyanate (TODI), phenylenediocyanate, paraphenylene. Diisocyanate (PPDI) and the like can be mentioned.
In the present invention, the term "MDI" as a diisocyanate compound includes not only unmodified MDI but also modified MDI. Examples of the modified MDI include carbodiimide-modified MDI (liquid MDI).

The diisocyanate compound preferably contains one or more of the above-exemplified diisocyanate compounds. The ratio of one or more of the above-exemplified diisocyanate compounds to the whole of the above-mentioned mixture is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and further preferably 80 to 100% by mass. It is preferable, and 90 to 100% by mass is particularly preferable. It is more preferable that all of the diisocyanate compounds in the mixture are one or more of the above-exemplified diisocyanate compounds.
From the viewpoint of further enhancing the safety to the living body, the diisocyanate compound is preferably MDI (including liquid MDI).

[Polyisocyanate compound of trivalent or higher]
The above trivalent or higher valent polyisocyanate compound is a compound having three or more isocyanate groups in one molecule. Specific examples of trivalent or higher valent polyisocyanate compounds include those derived from polypeptide MDI (Crude MDI), MDI prepolymers, and 1,3,5-tris (6-isocyanate hexa-1-yl) 1,3,5. -Triazine-2,4,6 (1H, 3H, 5H) -Trione and the like can be mentioned. These are also excellent in terms of safety for living organisms.
Further, a dimer (uretidine conjugate) of hexamethylene diisocyanate, a trimer (isocyanurate conjugate) or a mixture thereof may be used in combination.

The trivalent or higher valent polyisocyanate compound preferably contains one or more of the above-exemplified trivalent or higher valent polyisocyanate compounds. The ratio of one or more of the above-exemplified trivalent or higher-valent polyisocyanate compounds to the above-mentioned trivalent or higher-valent polyisocyanate compound in the above-mentioned mixture is preferably 50 to 100% by mass, more preferably 70 to 100% by mass. Preferably, 80 to 100% by mass is more preferable, and 90 to 100% by mass is particularly preferable. It is more preferable that all of the trivalent or higher valent polyisocyanate compounds in the mixture are one or more of the above-exemplified trivalent or higher valent polyisocyanate compounds.

The ratio of the content of the diisocyanate compound to the total content of the diisocyanate compound and the trivalent or higher polyisocyanate compound in the above mixture can be 40% by mass or more, preferably 45 to 90% by mass. , 50-85% by mass is also preferred.

The contents of the diisocyanate compound and the trivalent or higher valent polyisocyanate compound in the mixture should be appropriately set according to the purpose in consideration of the amounts of amino groups, hydroxyl groups and isocyanate groups of each compound in the mixture. Can be done. For example, the total content of the diisocyanate compound and the trivalent or higher valent polyisocyanate compound can be 10 to 160 parts by mass with respect to 100 parts by mass of the polyamine compound, and is 20 to 130 parts by mass. It is also preferable that the amount is 30 to 100 parts by mass.

In the above mixture, [isocyanate group equivalent of diisocyanate compound and trivalent or higher polyisocyanate compound] / [active group equivalent of amino group equivalent of aromatic polyamine oligomer and aromatic diamine compound and hydroxyl group equivalent of polyol compound] ( Hereinafter, this equivalent ratio [NCO / (NH ₂ + OH)] is also referred to as an isocyanate index (NCO index), preferably 0.95 to 1.50, and more preferably 0.95 to 1.30. , More preferably 1.00 to 1.20. When the isocyanate index is in the above range, the softening point of the polyurea is less likely to decrease, the heat resistance can be further enhanced, and the hardness and elasticity of the polyurea can be stably obtained.

In the grindstone of the present invention, the polyurea resin as a binder has physical properties (hard and rubber elasticity) peculiar to the polyurea resin, and its durability under high temperature and high humidity conditions is effectively enhanced. ing. The reason for this, including estimation, will be explained below.

In the polymerization reaction in the synthesis of polyurea, usually, first, the amino group of the polyamine compound and the isocyanate group of the polyisocyanate compound react to form a so-called linear polyurea structure, and then the activity of the residual isocyanate group and the urea bond. Hydrogen reacts to form crosslinks due to the formation of bullet crosslinks, or each urea bond portion aggregates to form pseudocrosslinks. As a result, polyurea is considered to exhibit excellent rubber elasticity. However, the above-mentioned cross-linking point is easily cleaved by heat, and the conventional polyurea resin does not show durability against repeated sterilization treatment under high temperature and high pressure required for denture material grinding / polishing applications.
On the other hand, in the grindstone material of the present invention, in addition to the diisocyanate compound, a trivalent or higher polyisocyanate compound is used in combination, and then a trivalent or higher polyol compound is also added to the mixture. By carrying out the polymerization reaction as such a compounding raw material, first, the reaction between the amino group and the isocyanate group having a high reaction rate proceeds preferentially to form a polyurea structure, and then the polyisocyanate compound having a trivalent or higher valence is formed. It is considered that the derived residual isocyanate group reacts with the polyol compound to form a three-dimensional crosslink based on a strong branched structure in the molecule. By such a stepwise reaction, polyurea having peculiar characteristics has a crosslinked structure that is stable against moist heat treatment while exhibiting physical properties (hard and rubber elastic) peculiar to polyurea resin. Resin is obtained.
Therefore, the grindstone material of the present invention using such a polyurea resin as a binder has excellent durability against repeated sterilization treatments under high temperature and high pressure (for example, autoclave sterilization treatment) required for grinding and polishing of artificial tooth materials. It is thought to show.
As described above, the binder constituting the grindstone material of the present invention is a three-dimensionally crosslinked insoluble / insoluble polymerized cured product obtained through various reactions, and its structural analysis is practically performed. Have difficulty. Therefore, in the present invention, in order to clarify the difference from the one according to the prior art and clarify the invention, the manufacturing method (process) is set as an invention-specific matter in the invention of the grindstone material.

[Abrasive grain]
As the abrasive grains used in the abrasive stone material of the present invention, alumina such as white arandom (WA) and arandom (A), silicon carbide such as green carborundum (GC) and carborundum (C), and diamond (nickel-coated diamond) are used. Includes), cubic boron nitride (CBN), ferric oxide, manganese oxide, chromium oxide, silicon dioxide (quartz molten silica, colloidal silica, fumed silica), cerium oxide, zirconium oxide, calcium carbonate, barium carbonate, oxidation One type or a mixture of two or more types of magnesium, mica, etc. can be used.
The particle size of the abrasive grains is not particularly limited, and abrasive grains having a particle size suitable for the purpose are adopted. As the abrasive grains, for example, ultrafine particles having a size of # 60 mesh to 1 μm or smaller can be used. That is, the grindstone material of the present invention can be used from the manual grinding process of the denture material to the precision polishing process.
The above "mesh" means the number of squares per inch (25.4 mm). For example, # 60 mesh is a mesh with 60 squares per inch.

The content of the abrasive grains in the grindstone material of the present invention is preferably 40 to 90% by mass from the viewpoint of grindability / abrasiveness and the fixing force of the abrasive grains by the polyurea resin. The content is the same as the compounding mass of the abrasive grains in the total mass of the raw materials excluding the solvent.

[Other ingredients]
A curing catalyst may be added in the production of the grindstone material of the present invention. Examples of curing catalysts include amine-based ones such as triethylenediamine and those in which it is dissolved in a glycol solvent, DABCO-1027, DABCO-1028, DABCO-33LV (all trade names) manufactured by Sankyo Air Products Co., Ltd., N. , N, N', N'-tetramethyl-1,6-hexanediamine, N, N-dimethylcyclohexylamine, (N, N-dimethylaminoethyl) ether and the like. Further, organic acid salts (potassium acetate salt, potassium oxalate salt, etc.) and organic metal catalysts (dibutyltin dilaurate, stunner octate, etc.) can be mentioned.
These can be used alone or in combination of two or more. The preferable amount to be used is 5 parts by mass or less with respect to 100 parts by mass of the polyamine compound.

The grindstone material of the present invention may contain titanium oxide, red iron oxide, iron oxide, graphite, hindered amine-based, hindered phenol-based, and thiazole-based compounds as a filler.
Further, the grindstone material of the present invention may contain polyester fiber, polyamide fiber, glass fiber, wool, cotton, silk and the like as a fibrous substance (fibrous filler). When the grindstone material of the present invention contains a fibrous filler, the content (mass%) of the fibrous filler in the grindstone material is preferably 1 to 15% by mass, and preferably 3 to 13% by mass. It is more preferably 5 to 12% by mass, further preferably 5 to 12% by mass. The content (mass%) of the fibrous filler in the grindstone material indicates the ratio of the mass (mass) of the fibrous filler to the total mass of the raw materials excluding the solvent.
Further, even if the grindstone material of the present invention contains bubbles such as a polymer hollow microsphere composite (particle size 10 to 14 μm), for example, Matsumoto Microsphere-MFL series, inorganic hollow microspheres (silica), etc. good.

The density of the grindstone material of the present invention is appropriately set according to the purpose. For example, in the 0.4~3.5g / cm ^3, it may be a 0.8~3.3g / cm ^3, may be a 1.0 to 3.0 g / cm ^3.

[Manufacturing of grindstone material]
Subsequently, the method for producing the grindstone material of the present invention will be described.
The method for producing the grindstone material of the present invention is not particularly limited as long as it includes polymerizing and curing the above mixture. For example, the descriptions of Japanese Patent No. 6489465, Japanese Patent No. 4357173, and Japanese Patent No. 3921056 can be appropriately referred to.
For example, at least a mixture of an aromatic polyamine oligomer, an aromatic diamine compound, a trivalent or higher polyol compound, and an organic solvent, abrasive grains, a diisocyanate compound, and a trivalent or higher polyisocyanate compound are mixed, and the mixture is used. The grindstone material of the present invention can be obtained by polymerizing and curing the mixture. As this polymerization curing reaction, for example, the above mixture is placed in a mold to proceed with the polymerization reaction, the mold is removed from the mold, and the cured product is further cured at 100 to 140 ° C. for several hours to obtain a grindstone material. obtain.

As the organic solvent, a solvent having high solubility in a polyamine compound such as acetone, ethyl acetate, methyl ethyl ketone, methylene dichlorite can be used alone, or HFC-365mfc (CF ₃ CH ₂ CF ₂ CH ₃ ), n- One or more low-solubility solvents selected from pentane, cyclopentane, n-hexane, n-heptane, cyclohexane and the like may be appropriately mixed and used. Mixing appropriately in this way has the effect of shortening the demolding time after casting, which is preferable.

Next, the present invention will be further described with reference to Examples, but the present invention is not limited to these Examples.
The following raw materials were used.

[Polyisocyanate compound]
-Liq MDI (liquid MDI), Coronate MX (manufactured by Tosoh Corporation, NCO content 29.0% by mass)
-CMDI (Crude MDI), Millionate MR200 (manufactured by Tosoh Corporation, NCO content 31.0% by mass, containing about 40% by mass of diisocyanate compound and about 60% by mass of trivalent or higher polyisocyanate compound among all isocyanate compounds. .)

[Aromatic polyamine oligomer]
Erasmer 1000P: Poly (tetramethylene oxide) -di-p-aminobenzoate (manufactured by Kumiai Chemical Industry Co., Ltd., amine value 98.68 KOHmg / g)

[Aromatic diamine compound]
CUA-4: Trimethylene-bis (4-aminobenzoart) (manufactured by Kumiai Chemical Industry Co., Ltd., amine value 351.2 KOHmg / g)
-TCDAM: 4,4'-methylenebis (2,3-dichlorobenzeneamine) (manufactured by Kumiai Chemical Industry Co., Ltd., amine value 319.2 KOHmg / g)
DD1604: 4-chloro-3,5-diamino-benzoic acid isobutyl ester (manufactured by Bayer, amine value 462.4 KOHmg / g)

[Polyol compound]
・ Glycerin (GC) [manufactured by Can Tho Chemical Co., Ltd.]
-Trimethylolpropane (TMP) [manufactured by Can Tho Chemical Co., Ltd.]
-Triethanolamine (TEA) [manufactured by Can Tho Chemical Co., Ltd.]

[Organic solvent]
・ Acetone (manufactured by Can Tho Chemical Co., Ltd.)
-365 mfc: 1,1,1,3,3-pentafluorobutane (manufactured by Nippon Solvay)

[Abrasive grain]
Diamond Abrasive Grain D _200-230 (particle size # 200-230 mesh) [manufactured by Tomei Diamond]
-D _270-325 (particle size # 270-325 mesh) [manufactured by Tomei Diamond]
・ D _{10-20 (particle size 10 to 20} μm) [manufactured by Tomei Diamond]
・ D _4-6 (particle size 4 to 6 μm) [manufactured by Tomei Diamond]
・ D _2-3 (particle size 2-3 μm) [manufactured by Tomei Diamond]

[Synthesis Examples 1-8]
According to the formulation (parts by mass) shown in Table 1, aromatic polyamine oligomers, aromatic diamine compounds, and polyol compounds (hereinafter, these components that react with isocyanate groups are collectively referred to as "curing components") are measured in a beaker. The mixture was heated above the melting point of all the curing components to dissolve the curing components to obtain a uniform solution. This solution is cooled to room temperature, and a predetermined amount of diisocyanate compound or diisocyanate compound and trivalent or higher valent polyisocyanate compound (hereinafter referred to as “isocyanate component”) are mixed according to the formulation (parts by mass) shown in Table 1 to 25. It was poured into a preheated mold at ~ 35 ° C., and after sufficient curing had progressed, the mold was removed. The obtained cured product was heat-treated at 120 ° C. for 6 hours to prepare sheet-shaped samples (polyurea resin) having a thickness of 5 mm.

[Sterilization test]
Each sample was autoclaved at 134 ° C. for 3 hours for sterilization. It has been confirmed that this sterilization treatment has the same load as the sterilization treatment in which the autoclave treatment for 10 minutes at 134 ° C. is repeated as many times as 30 times.

1) Liq MDI / CMDI = 1/1 (mass ratio)
2) [Amount of aromatic diamine compound used (g) / Molecular weight of aromatic diamine compound] / [Amount of aromatic polyamine oligomer used (g) + amount of aromatic diamine compound used (g)]
3) [Isocyanate group equivalents of diisocyanate compounds and polyisocyanate compounds of trivalent or higher] / [Active group equivalents obtained by combining amino group equivalents of aromatic polyamine oligomers and aromatic diamine compounds with hydroxyl group equivalents of polyol compounds]
4) [Amount of polyol compound used (g) / Molecular weight of polyol compound] / [Amount of aromatic polyamine oligomer used (g) + amount of aromatic diamine compound used (g)]
5) A D-type hardness tester was pressed from above against a sheet-shaped polyurea resin having a thickness of 5 mm, and the value indicated by the needle was defined as the hardness.
6) 100 × Volume of sample after immersion in DMF / Volume of sample before immersion in DMF = {[Swelling sample mass (g) after immersion in dimethylformamide (DMF) for 7 days at 22 ° C. − Sample before immersion Mass (g)] /0.9445+ Volume of sample before immersion (cm ³ )} / Volume of sample before immersion (cm ³ )
0.9445: Density of DMF at 22 ° C. (unit: g / cm ³ )
-Volume of sample before immersion (cm ³ ) = Mass of sample before immersion (g) / Density of sheet-shaped sample (g / cm ³ )
7) 100 × Hardness of sample after sterilization treatment / Hardness of sample before sterilization treatment (The hardness of the sample after sterilization treatment is after sterilization treatment, drying at 80 ° C. for 12 hours, and then conditioning at 22 ° C. for 1 week. Hardness.)
8) DMF swelling degree of the sample after sterilization treatment / DMF swelling degree of the sample before sterilization treatment

As shown in Table 1 above, the polyurea resin of Synthesis Example 7 in which a polyisocyanate compound having a valence of 3 or more is not blended and the polyurea resin of Synthesis Example 8 in which a polyol compound is not blended have low hardness. The degree of DMF swelling was high. In addition, the polyurea resins of Synthesis Examples 7 and 8 had a low hardness retention rate after the sterilization treatment, and the sterilization treatment resulted in a large increase in solubility in DMF.
On the other hand, the polyurea resins of Synthesis Examples 1 to 6 having the binder composition of the grindstone material of the present invention have relatively high hardness and low DMF swelling degree, and these characteristics are well maintained even by sterilization treatment. rice field.

[Examples 1 to 8]
According to the formulation (parts by mass) shown in Table 2, a mixture of the curing component and the organic solvent (acetone / 365 mfc = 7/3 (mass ratio)) was measured in a beaker to obtain a uniform solution. A predetermined amount of abrasive grains are added to and dispersed in this solution according to the formulation (parts by mass) shown in Table 2, and then a predetermined amount of isocyanate components are mixed, and the mixture is placed in a mold on which a shaft is installed at room temperature. Infused. After polymerization and curing of the mixture, the mixture was demolded and heat-treated at 120 ° C. for 5 hours to obtain a grindstone material with a columnar shaft having a diameter of 6 mm and a length of 18 mm. This grindstone material was processed into a cannonball shape at the upper part with a plate-shaped diamond grindstone to obtain a grindstone material.
Here, the symbols of the cured components in Table 2 (“A”, “AG”, “AM”, “AE”, “BG”, “CG”, “DG”. ”) Corresponds to the“ abbreviation ”of the curing component shown in Table 1. That is, it means that each curing component was blended at the same blending ratio as the blending ratio of the cured components shown in Table 1. For example, in Example 1 in which the abbreviations are A and G in Table 2, each curing component is blended in a blending ratio of E1000P: CUA-4: GC = 80: 20: 4.8 (mass ratio). It means that 17.7 parts by mass was used with respect to 100 parts by mass of abrasive grains. Further, the code "β" of the isocyanate component in Table 2 is a mixed product of Liq MDI / CMDI = 1/1 (mass ratio) as in Table 1.

<Grinding / polishing test>
An electric hand grinder with a grindstone attached is ground on a zirconia work surface (0.7 cm x 0.7 cm flat surface) that looks like a prosthetic tooth material at a rotation speed of 10000 rpm and a force of about 200 g in the vertical direction over 15 seconds. Next, it was ground in the horizontal direction for 15 seconds, and then again in the vertical direction for 15 seconds, and the entire work surface was ground and polished to obtain a finished surface. The arithmetic average roughness Ra of the finished surface, the ten-point average roughness Rz, and RΔq as the glossiness were measured by a surf test ST.410 manufactured by Mitutoyo Co., Ltd.

1) It is synonymous with the isocyanate index in Table 1.
2) The hardness was measured in the same manner as in Table 1.
3) 100 × Physical characteristics before sterilization / Physical characteristics after sterilization

The binder of the grindstone material of Comparative Example 1 has the same composition as the polyurea resin of Synthesis Example 8 in Table 1. The grindstone material of Comparative Example 1 can be ground and polished in a ductile mode, and has good smoothness and glossiness of the finished surface. However, when this grindstone material was used after being sterilized, the finished surface could not have the desired smoothness and glossiness. In other words, the sterilization process resulted in a significant decrease in performance.
On the other hand, the grindstone materials of Examples 2 to 7 could be finished into a sufficiently smooth and highly glossy finished surface even after the sterilization treatment.

[Examples 8 to 10]
According to the formulation (parts by mass) shown in Table 3, a mixture of the curing component and the organic solvent (acetone / 365 mfc = 8/2 (mass ratio)) was measured in a beaker to obtain a uniform solution. This solution is shown in Table 3. After adding and dispersing a predetermined amount of abrasive grains according to the composition (parts by mass), a predetermined amount of isocyanate component is mixed according to the composition (parts by mass) shown in Table 3, and the mixture is placed at room temperature in a mold on which a shaft is installed. After the mixture was polymerized and cured, the mixture was demolded and heat-treated at 120 ° C. for 5 hours to obtain a grindstone material with a columnar shaft having a diameter of 6 mm and a length of 18 mm. Was processed into a bullet shape to obtain a grindstone material.

1) It is synonymous with the isocyanate index in Table 1.
2) The hardness was measured in the same manner as in Table 1.

[Evaluation of grinding / polishing property-1]
An electric hand grinder equipped with a vitrified grindstone that is generally used for dentistry is placed on a zirconia work surface (0.7 cm x 0.7 cm flat surface) that looks like a prosthetic tooth material at a rotation speed of 10000 rpm and a force of about 200 g. Rough grinding was performed in the vertical direction for 15 seconds, then rough grinding was performed in the horizontal direction for 15 seconds, and the entire work surface was roughly ground again in the vertical direction for 15 seconds to obtain a rough ground surface.
Next, the electric hand grinder to which the grindstone material of Example 7 was attached was ground on the rough ground surface under the above conditions to obtain a ground surface.
Then, the electric hand grinding machine to which the grindstone material of Example 8 was attached was applied to the ground surface under the above conditions for intermediate finishing to obtain a semi-finished surface.
Finally, the electric hand grinder to which the grindstone material of Example 9 was attached was applied to the semi-finished surface under the above conditions to finish the finished surface.
Rough grinding with the above-mentioned grindstone was in the brittle mode, and grinding / polishing with each of the grindstone materials of Examples 7 to 9 was in the ductility mode. The arithmetic average roughness Ra, ten-point average roughness Rz, and glossiness of each of the rough-ground surface, the ground surface, the semi-finished surface, and the finished surface were measured by Mitutoyo's surf test ST.410. The results are shown in Table 4.

It was confirmed that zirconia, which is expected to be widely used as a denture material in the future, is ground and polished using three types of grindstone materials of the present invention having different grain sizes to have extremely smooth and glossy properties. Was done.

[Evaluation of grinding / polishing property-2]
The electric hand grinder to which the grindstone material of Example 8 was attached was provided with a zirconia work surface (0.7 cm × 0.7 cm flat surface) and a cobalt / chrome alloy work surface (0.7 cm × 0. For each of the 7 cm flat surfaces), take 15 seconds in the vertical direction with a force of about 200 g at a rotation speed of 10000 rpm, then take 15 seconds in the horizontal direction, and then again in the vertical direction for 15 seconds to complete the entire work surface. Was ground and polished to obtain a semi-finished surface. Next, the electric hand grinder to which the grindstone material of Example 9 was attached was applied to the semi-finished surface under the above conditions to finish the finished surface. All grinding and polishing was done in ductile mode. The arithmetic average roughness Ra, ten-point average roughness Rz, and root mean square slope RΔq of the semi-finished surface and the finished surface were measured by Mitutoyo's surf test ST.410. The results are shown in Table 5.

Using two types of grindstone materials of the present invention with a particle size of 20 μm or less and different grain sizes, zirconia rough surfaces and cobalt / chromium alloy rough surfaces, which are expected to be widely used as artificial tooth materials in the future, are polished. As a result, it can be seen that a finished surface that is extremely smooth and has excellent glossiness can be obtained. That is, if the grindstone material of the present invention is used, a rough surface of zirconia or a rough surface of a cobalt / chromium alloy, which has been difficult to be precision-polished in the past and is a desired finished surface through a number of steps, can be obtained with only two types of grindstone materials. It can be seen that by using it, a finished surface with excellent smoothness and glossiness can be obtained.

[Evaluation of grindability / polishability-3]
The electric hand grinder to which the grindstone material of Example 10 is attached is provided with a hybrid resin work surface (0.7 cm × 0.7 cm flat surface) and a composite resin work surface (0.7 cm × 0.7 cm) having a rough surface shown in Table 6. The entire work surface is polished by applying a force of about 200 g at a rotation speed of 8000 rpm for 15 seconds in the vertical direction, then 15 seconds in the horizontal direction, and then 15 seconds in the vertical direction again. I got a finished surface. All polishing was done in ductile mode. The arithmetic average roughness Ra of the finished surface, the ten-point average roughness Rz, and RΔq as the glossiness were measured by a surf test ST.410 manufactured by Mitutoyo Co., Ltd. The results are shown in Table 6.

By using the grindstone material of the present invention, even for hybrid resins and composite resins, which were difficult to mirror with conventional grindstone materials, polishing with only one grindstone material is extremely smooth and glossy. It can be seen that an excellent finished surface can be obtained. That is, the grindstone material of the present invention can greatly improve the work efficiency of precision polishing of the denture material.

Claims (14)

A polyurea composite grindstone material for grinding and polishing artificial tooth materials, which is obtained by polymerizing and curing a mixture containing a polyamine compound, a trivalent or higher-valent polyol compound, a diisocyanate compound, a trivalent or higher-valent polyisocyanate compound, and abrasive grains. The polyurea composite grindstone material for grinding and polishing a denture material according to claim 1, wherein the polyamine compound contains any of the following (a) to (d).
(A) Aromatic polyamine oligomers (b) Aromatic polyamine oligomers and aromatic diamine compounds (c) aliphatic polyamine oligomers, aromatic polyamine oligomers and aromatic diamine compounds (d) aliphatic polyamine oligomers and aromatic polyamine oligomers The artificial tooth material grinding according to claim 2, wherein the polyamine compound contains an aromatic polyamine oligomer and an aromatic diamine compound, and the ratio of the aromatic diamine compound to the polyamine compound in the mixture is 40% by mass or less. Polyurea compound grindstone for polishing. The polyurea composite grindstone material for grinding and polishing a denture material according to claim 2 or 3, wherein the aromatic polyamine oligomer contains a polyamine oligomer represented by the following formula (I).

In the formula, R represents a residue of a polyalkylene polyol, a polyalkylene ether polyol or a polyalkylene ester polyol having an n-valent number average molecular weight of 200 or more, and n represents 2 or 3. However, the polyalkylene may contain an unsaturated bond. The aromatic diamine compound is trimethylene-bis (4-aminobenzoate), 4-chloro-3,5-diaminobenzoic acid isobutyl ester, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid diethyl ester, And 2,2', 3,3'-tetrachloro-4,4'-diaminodiphenylmethane for grinding and polishing artificial tooth materials according to any one of claims 2 to 4, which contains one or more of diaminodiphenylmethane. Polyurea composite abrasive. The artificial tooth material according to any one of claims 1 to 5, wherein the trivalent or higher-valent polyol compound contains a polyol compound having 3 to 6 hydroxyl groups in one molecule and a molecular weight of 92 to 600. Polyurea compound grindstone material for grinding and polishing. Any of claims 1 to 6, wherein the trivalent or higher valent polyol compound comprises one or more of glycerin, trimethylolpropane, triethanolamine, hexanetriol, pentaerythritol, diglycerin, and methylglucoside. The polyurea composite abrasive for grinding and polishing of artificial tooth material according to item 1. The polyurea composite grindstone material for grinding and polishing a denture material according to any one of claims 1 to 7, wherein the diisocyanate compound contains diphenylmethane diisocyanate. The above-mentioned trivalent or higher-valent polyisocyanate compound is derived from polypeptide diphenylmethane diisocyanate, trivalent or higher-valent diphenylmethane diisocyanate prepolymer, and 1,3,5-tris (6-isocyanatohex-1-yl) 1,3. , 5-Triazine-2,4,6 (1H, 3H, 5H) -Polyurea composite grindstone for grinding and polishing prosthesis according to any one of claims 1 to 8, which contains at least one of trions. .. The method according to any one of claims 1 to 9, wherein the ratio of the content of the diisocyanate compound to the total content of the diisocyanate compound and the trivalent or higher polyisocyanate compound in the mixture is 40% by mass or more. Artificial tooth material Polyurea composite grindstone material for grinding and polishing. The polyurea composite grindstone material for grinding and polishing a denture material according to claim 10, wherein the diphenylmethane diisocyanate contains a carbodiimide-modified diphenylmethane diisocyanate. The artificial tooth according to any one of claims 1 to 11, wherein the content of the trivalent or higher polyol compound is 2 to 17 parts by mass with respect to 100 parts by mass of the polyamine compound in the mixture. Polyurea composite grindstone material for material grinding and polishing. The polyurea composite grindstone material for grinding and polishing a denture material according to any one of claims 1 to 12, wherein the density of the polyurea composite grindstone material is 0.4 to 3.5 g / cm ^3. A mixture of an aromatic polyamine oligomer, an aromatic diamine compound, a trivalent or higher polyol compound and an organic solvent, abrasive grains, a diisocyanate compound and a trivalent or higher polyisocyanate compound are mixed, and this mixture is polymerized and cured. A method for producing a polyurea composite grindstone for grinding and polishing a prosthetic tooth material, including the above-mentioned method.