JPS61143417A - Polyurethane elastomer for dental use, and method for forming multi-layered structure using same - Google Patents

Abstract

PURPOSE:To provide the titled elastomer for dental use, having improved strength in weakly acidic or weakly alkaline state, easily controllable flexibility, and high resistance to yellowing, and moldable in multiple layers, by reacting a specific polyol with a non-aromatic diisocyanate. CONSTITUTION:The objective elastomer can be produced by reacting (A) one or more polyols selected from polycarbonate polyol, polybutadiene polyol and polycyclohexanedial and (B) a non-aromatic diisocyanate (preferably isophorone diisocyanate as the diisocyanate component. In the case fo reacting (C) a crosslinking agent to the components A and B, a primary structure is formed from a prepolymer of the resting stage of the reaction and containing a proper amount of unreacted terminal isocyanate groups, and the secondary structure is formed in contact with the primary structure using a prepolymer having OH group or NH2 group at the terminal or at the side chain, to form a multiple layer structure.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to denture bases, maintenance structures, mouthpieces and orthodontic devices.
The present invention relates to a polyurethane elastomer suitable for the dental field, such as gingival material, and a method for forming a polyurethane elastomer multilayer structure using the same. (Prior art) An attempt to use polyurethane elastomer as a dental material was already proposed by Mr. Miyake and others over 20 years ago, but the original polyurethane elastomer had many drawbacks in its physicochemical properties, and There were also many unconfirmed points regarding its safety as a material. Since then, with the development of polyurethane technology, the above-mentioned problems have gradually been improved, but the following improvements still remain as dental materials. (Problems to be solved by the invention) Namely, (1) conventional polyurethane elastomers tend to deteriorate in strength in weakly acidic or slightly alkaline conditions in the oral cavity; (1) the hydrophilicity of polyurethane is However, on the other hand, it was found that this hydrophilicity caused contamination. (fil) If it is left exposed to sunlight for a long time, it will turn yellow and become a color that is incongruous with the color of living tissue, reducing its commercial value. Therefore, the purpose of the present invention is to solve the above three problems.The present invention has the objective of solving the above-mentioned three problems. By arranging a polyurethane elastomer material, a variety of molecular designs are possible, and a rigid polyurethane elastomer material and a flexible and highly elastic polyurethane elastomer material, or a polyurethane elastomer material and other materials can be bonded to each other in a highly chemically bonded state. We also provide a method that can realize a functional multilayer structure by stacking them together. (Means for Solving the Problems) The present inventors have been conducting intensive research for many years on the development and research of dental polyurethane elastomers from both polymer technology and clinical viewpoints. the result. A dental polyurethane elastomer made of a reaction product of at least one polyol selected from polycarbonate polyol, polybutadiene polyol, and polysiloxane diol and a non-aromatic diisocyanate as a diisocyanate is effective for solving the above problems. I knew that it was. As a polyol to make the degree of hydrophilicity or hydrophobicity in the elastomer. This can be defined because polyethers and polythioethers with ether bonds are difficult to hydrolyze, but it has been found that the water absorption of elastomers becomes large even though the ether bonds themselves are not hydrolyzed, so that the purpose cannot be achieved. As a result of such repeated trial and error, polycarbonate polyols, polybutadiene polyols, and polysiloxanes with a low content of ester bonds were selected as polyols that should be able to make part of their hydrophilic properties hydrophobic without sacrificing adhesive properties. It has been found that at least 121 selected from diols are optimal. Although there is a difference in that the former has better mechanical properties than the latter, both can impart good hydrolysis resistance to the elastomer. On the other hand, diisocyanate, which is a hard segment, is an alicyclic diisocyanate with an alicyclic structure. Non-aromatic diisocyanates such as Inphorone Diisocyanate (IPDI) are necessary to achieve strong non-yellowing properties. As a crosslinking agent for forming a urethane bond between the above-mentioned polyol and this non-aromatic diincyanate,
methylene bis-ortho-chloraniline (MOCA),
X-Ken 4-butanediol-trimethylol dielectric pan and the like are used. The hardness of the elastomer can be adjusted by selecting the amount of polyol, the amount of diisocyanate, and the amount of crosslinking agent. 5L@,
The distribution is such that the older the layer, the harder it is. Normally, by setting the polyol to about 1.08%, the crosslinking reaction will be completed, so if the multilayer structure described later is not adopted, the above N0"Ck0 Distribution 1F T 2 V g jJ-r-
Cross-linking and curing is completed simply by pouring into the cast melon, and there is no need to carry out injection molding. However, when adopting a multilayer structure, 1.
There is a method to prevent curing in a viscous state for a long period of time by increasing the number of free isocyanates to approximately 05 to L2S, thereby causing a large number of free isocyanates to exist in the crosslinking reaction state, thereby significantly inhibiting chain extension and delaying curing. It becomes necessary. In this case, the multilayer structure refers to the rigidity required for the parts of the denture base that are subject to strong occlusal pressure, and the flexibility required for the parts that are less affected by occlusal pressure and in contact with the mucosal tissue. As mentioned above, the polyurethane elastomers of the present invention have different physical properties so as to be adaptable to different properties (however, they are distinguished by hardness and softness).1 The elastomer of the present invention and a separate prepolymer.

[For example, a primer coated on a polymeric material different from metal or polyurethane], etc. in a multilayered manner: Achieves multiple functions while using a single denture base as a laminated adhesive unit. Casting such a large number of structural members in separate cycles is not only disadvantageous in terms of process, but also requires embedding technology based on injection molding. The chemical adhesion is also insufficient. Therefore, in the present invention, in order to form such a multilayer structure, by considering the NCO ratio as described above, a large number of free NCO groups remain and the rotation area is maintained without causing the elastomer to reach final curing (this (reactive dormant state)
, pIg1 was obtained by filling molding using the polyurethane material of the present invention whose NCO ratio t was adjusted to reach this state.
The next structure is formed, followed by the terminal or side chain K in the molecule.
Another polyurethane prepolymer of the present invention having OH groups or NHt groups or known polyurethane elastomi
- or other elastomer to form a secondary structure in contact with the primary structure, which is achieved by VC. In order to adjust the NCO ratio v4, conventionally known chain extenders 1, such as polyols, polyamines, alkanolamines, etc., should be added in combination. ・The structure is Layabatake film ・Other types This includes any molded member having the shape of. In the above method, the polymerization of the primary structure is preliminarily advanced by heating before the secondary structure is poured into the secondary structure to shorten the final polymerization time. In the elastomer of the present invention, the NCO ratio is 1.05 to 1, which is desired in the sense that the primary structure does not undergo rotational changes when poured.
．． If it is set to about 21%, it will be 100-113! ″T:j,
Heating for 24 to 36 hours causes the reaction with atmospheric moisture to reach the final reaction state. Therefore, preliminary polymerization can be carried out by keeping the heating temperature below the above range for one hour. An example of the secondary structure is a primer coated on a polymeric material different from metal or polyurethane.For example, when a metal member and a polyurethane elastomer member of the present invention are combined, the elastomer A single layer of primer is placed on the metal member that should be located between the primary structure member 1 and the manufactured member (as described above, this primer has an OH group or NH! group at the end or its side chain). can be considered as a secondary structure, and a medium can be added as a standalone structure or as a police force if necessary. A specific example of obtaining such a multilayer structure will be described with reference to FIG. S, taking a denture base as an example. In the ζ0 case, the main body U of the denture base (1) excluding the front tooth part (4)
This shows a case in which the front tooth part (T) is made of a rigid polyurethane elastomer (i.e., rich in diisothi, 1--)), and the front tooth part (g) is made of a flexible polyurethane elastomer C (i.e., polyol-rich). (2) Put the former elastomer prepolymer cO containing a crosslinking agent into the circle, and adjust the NCO ratio to <1. OS~1,! 5 and C chain extender (3) and injected into the molding container, followed by pre-electropolymerization at 80°C for 1 to 2 hours to increase the viscosity and then release the molded material. Particularly, the injection material corresponding to the front tooth part (G) is peeled off, and then another piece (8) is butted against the mold holder, and a flexible polyurethane prepolymer prepared in another container (4) is poured. and NCO ratio t-LO5#L! 5
Mix with the chain lengthening agent (5) so that the mold (A)
, (3) between 1! Inject into the cavity corresponding to part i,
After that, prevo v-q-co, c at 0℃ for 12 hours.
! Complete the polymerization in step 11. Next, the main body part U made of rigid polyurethane elastomer υ and the front tooth part (9) made of flexible polyurethane elastomer are bonded with chemical affinity at the interface between the two. The integrated denture base (1) is separated, and then this denture base (1) is polished to become a human product. (Function) By selecting a polyol with few ester bonds, such as polycarbonate polyol or bolibu-tadiene polyol, we give the elastomer good hydrolysis resistance and increase its strength under weak acid, weak alkaline conditions. It becomes possible to improve the flexibility and change the flexibility by adjusting the amount of polyol. In this case, there is no need to sacrifice adhesive properties, and stable non-yellowing can be ensured by selecting a non-aromatic diisocyanate, and by using the above polyol, part of the hydrophilicity in the elastomer can be changed to hydrophobicity. NC has the advantage of not discoloring even after long-term use with the consequent reduction in contamination that can be achieved with NC.
By adjusting the O ratio, a complete reaction resting state can be created, and it can be chemically strongly bonded and integrated with other layer-forming prepolymers having OH groups or NHt groups at the terminal or side chain, so it can be carried out by pour molding technology. This method is extremely advantageous. (Example) (Example 1) a) Polyol - Polycarbonate polyol [Bayer AG's trademark Desmo-phen * Product number '2020] 50 parts Polybutadiene polyol (manufactured by Idemitsu Oil Co., Ltd.) 50 parts b) Diisocyanate - Inphorone diisocyanate ( IPDI) 2 a part C] Crosslinking agent-1 #4 butanediol 2-5 parts d) Pigment-
1 part (Example 2) 1) Polyol-Desmophen a $2020
Woo part diphosphorus (MOCA) io part d) Pigment - 1 part (Example 3) Cloud a) Polyol - Desmophen a 2020
Woo part b) Diincyanate -IPDI
30 parts C) Crosslinking agent-MOC
A 20 parts d) Pigment - 1 part (Example 4) a) Polyol - Desmophen * 2020
100 partsb) -IPDI
45 parts C) Crosslinking agent -MOC
A 37.5 parts d) Pigment - 1 part (physical properties 1) Comparison of physical properties between (Examples 1 to 4) and other materials (Table 1
). (Space below) (Physical properties 2) (a) Change in hardness in organic acids - The following organic acids, namely, CHsCOOH:C
t) 4COOH:CProverbHyCOOH:H,O! s:z:
The immersion time and hardness change (Shore value) in z:z:so (weight S) (Example 3) and Comparative Example (shown in the figure) are shown in FIG. (b) 100% modulus change - Fig. 2 shows the time of immersion in the same organic acid as in (b) and the change in 100% modulus of (Example 3) and a comparative example. (c) Change in tensile strength - time of immersion in the same organic acid as in (a) and change in tensile strength 1 - (Example 3) and a comparative example are shown in Figure @3. (b) Change in volume - Figure 4 shows the time and change in volume when immersed in the same organic acid as in (a) 1- (Example 3) and a comparative example. (Import of the Invention) (1) From Table 1, the elastomer of the present invention has an elongation of 160 to 20%, a tensile modulus of 400 to 1,40, and a tensile modulus of 400 to 1,40.
0. Compressive strength 400~1,200m Bending strength 25~l
40. A polyurethane elastomer has been obtained which is capable of achieving performance i; 111i ranging from a hard range to a hard range where it is non-destructive when subjected to @ impact. (1) From Figure 1, the change in hardness in organic acids shows behavior similar to that of the fluorine-based soft lining material. (it) As shown in FIG. 2, in the case of the present invention, the change in loo-ohata-so-dielas in the organic acid is very small. (lv) From FIG. 3, the change in tensile strength in organic acids is very small. From Fig. 4, the volume change in organic acid can be suppressed to the same swelling as crepate. As can be seen from the above results, the polyurethane disstomer of the present invention has properties necessary for a dental material that could not be achieved by conventional methods. In addition, it is possible to mold not only this single polyurethane elastomer but also the same polyurethane elastomer with different performance, or even cast molding with other polyurethanes or even other prepolymers to form a multilayer structure, making it suitable for dentistry. This brings great good news to engineers.

[Brief explanation of drawings]

Figures 1 to 4 show various performances of the polyurethane disstomer of the present invention under organic acid immersion, together with comparative examples. FIG. 3 shows changes in tensile strength, FIG. 4 shows changes in volume, and FIG. S is an explanatory diagram showing the procedure for forming a dental multilayer structure according to the present invention. (Symbol theory rs> 1 tooth bed% 2-container, 3- crosslinking agent, 4-container. 5- crosslinking agent, zo- front part, 11- main body part, 20.21
- Prepolymer, human - B - Deaf. -That's all- Mr. Deho Wada Precision Dental Co., Ltd. (and 2 others) Representative Patent Attorney (6235) Hidehiko Matsuno Figure 1 Figure 3111 Figure 4 wI Figure 5

Claims (1)

[Claims] 1. A dental polyurethane elastomer comprising a reaction product of at least one polyol selected from polycarbonate polyol, polybutadiene polyol, and polycycloxane diol and a non-aromatic diisocyanate as a diisocyanate. 2. The dental polyurethane elastomer according to claim 1, wherein the non-aromatic diisocyanate is isophorone diisocyanate. 3. The dental polyurethane elastomer according to claim 1 or 2, which contains one selected from methylene bis ortho chloroaniline, 1,4 butanediol, and trimethylolpropane as a crosslinking agent. 4. The dental polyurethane elastomer according to claim 3, wherein the final NCO/NH_2 or OH in the elastomer is 1.00 to 1.08. 5. Polycarbonate polyol as polyol,
When obtaining a polyurethane elastomer by reacting at least one selected from polybutadiene polyol and polycycloxane diol with a non-aromatic diisocyanate as a diisocyanate using a crosslinking agent, unreacted terminal isocyanate groups are appropriately removed during crosslinking. Forming a primary structure with a prepolymer that remains in a dormant state, and forming a primary structure with another prepolymer having an OH group or NH_2 group at the end or side chain of the molecule. A method for forming a dental polyurethane elastomer multilayer structure, comprising forming a secondary structure in contact with the primary structure. 6. Claim 5, wherein the other prepolymer is the polyurethane prepolymer described in Claim 1.
A method for forming a dental polyurethane elastomer multilayer structure as described in . 7. The method for forming a dental polyurethane elastomer multilayer structure according to claim 5, wherein the other prepolymer is a metal or a primer coated on a polymeric material different from polyurethane. 8. After forming the primary structure and before forming the secondary structure, prepolymerize the primary structure by heating, and after forming the secondary structure, apply heating to complete the polymerization of both structures. A method for forming a dental polyurethane elastomer multilayer structure according to any one of claims 5, 6, and 7, which includes carrying out the method. 9. NCO/NH_2 or OH during crosslinking is 1.05
A method for forming a dental polyurethane elastomer multilayer structure according to any one of claims 5, 6, 7, and 8, which comprises adding a chain extender such that the chain length is 1.25 to 1.25. 10. The method for forming a dental polyurethane elastomer multilayer structure according to claim 9, wherein the chain extender is a polyol, a polyamine, or an alkanolamine, singly or in combination.