JPH02247107A - Denture plate and production thereof - Google Patents

Abstract

PURPOSE:To provide a denture plate having an excellent impact strength by polymerizing and molding a mixture of a fluorine-containing copolymer and a monomer, alkyl (meth)acrylate ester, in a mold. CONSTITUTION:A mixture of (A) 5-70wt.% (preferably 30-60wt.%) of a fluorine- containing copolymer and (B) 30-95wt.% (preferably 40-70wt.%) of a monomer, alkyl (meth)acrylate ester, is polymerized and molded in a mold to prepare a denture plate. The component A comprises two kinds or more of monomers selected from vinyl fluoride, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene and hexafluoropropylene and the alkyl group of the component B has preferable 1-3 carbon atoms. The polymerization can be carried out with a polymerization initiator such as benzoylperoxide. The denture plate has an improved impact strength of >=0.75kg.cm.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a denture base with excellent mechanical strength.

More specifically, the present invention relates to a denture base made of a mixture of a fluorine-containing copolymer and an alkyl ester polymer or copolymer of acrylic acid or methacrylic acid, and a method for producing the same.

BACKGROUND OF THE INVENTION For a long time, denture base materials consisting of polymers of fulkylnisder (of acrylic acid or methacrylic acid) have been used. However, its weak mechanical strength, particularly its brittleness, has been a problem. For example, in patients with strong occlusal forces, the denture base may become fatigued and break during use, or may break when the denture base is inadvertently dropped on the floor. For this reason, the denture base has to be made thicker, which increases the patient's discomfort, and it is necessary to increase the mechanical strength of the denture base.
It was required that

To address this problem, proposals have been made to reinforce methacrylic acid methyl ester denture bases with carbon fiber cloth, and denture base materials that combine polymethacrylic acid methyl ester with siloxane polymer have been proposed, but these are still insufficient.
It has not yet been put into practical use. In addition to polymethyl methacrylate-based denture base materials, polyether 1-norphone and polycarbonate resin-based denture base materials are known, but these have the disadvantage of being inferior in workability and lacking in versatility compared to polymethyl methacrylate-based denture base materials.

SUMMARY OF THE INVENTION The present invention solves these drawbacks and provides a denture base with excellent mechanical strength, ease of construction, and versatility.

As a result of intensive research to solve the problem, the present inventors discovered that acrylic acid containing a fluorine-containing copolymer (Japanese Patent Application Laid-open No. 55-21919), which is conventionally known as a soft lining material for denture bases. Alternatively, the inventors discovered that a denture base made of a methacrylic acid alkyl ester polymer has excellent mechanical strength, leading to the present invention.

That is, the "I3 tooth base of the present invention is made of fluorine-containing copolymers 5. to 7.
0% by weight and acrylic acid alkyl ester (alkyl number (
(1 to 5 carbon atoms) and methacrylic acid argyl ester (
At least one selected from alkyl groups having 1 to 5 carbon atoms
30-95% by weight of polymer or copolymer of species intermediates
It has excellent mechanical strength.

The fluorine-containing copolymer in the present invention is disclosed in JP-A-55219
The soft fluororesin used as the denture base soft lining material described in Item 19 can be obtained in the same manner. That is, examples of fluorine-containing copolymers that are soft fluororesins include vinyl fluoride, vinylidene fluoride, dylene trifluoride, ethylene tetrafluoride,
Chloro 1 cotrivaloroethylene, hekiliflo [-1 b[]
Copolymers of two or more fluorine-based monoassemblies such as pyrene, hexafluoro-1 butylene, perfluoro[1-nitrosomethane, perfluoro-1]methylvinyl needle, and olefinic hydrocarbons that can be copolymerized with these fluoropolymers. It is one type or a mixture of two or more selected from copolymers consisting of monomers, fluorine-containing silicone rubber, fluorine-containing triazine rubber, and fluorine-containing fluorine-containing fluorine-containing sphazene rubber.

Preferably, it is a copolymer consisting of two or more monomers selected from vinyl fluoride, vinylidene fluoride, trifluoroethylene, fluoroethylene, and hexafluoropyrene.

Further, the manufacturing method thereof is not particularly limited as it can be obtained by a conventional method, but a suspension polymerization method that yields a powdery polymer is preferred.

The fluorine-containing copolymer in the present invention has a rigidity of 5 Ng/c
The rigidity can be arbitrarily adjusted to 1q depending on the combination of single feeder types and formulation.

The blending amount of the fluorine-containing copolymer in the present invention is 5 to 70
Weight%. Preferably it is 10 to 60% by weight, more preferably 30 to 60% by weight. If the amount of the fluorine-containing copolymer mixed is 5% by weight or less, see examples below! This is because the effect of improving strength in terms of M% is small, as explained in 2009.More than 70% by weight, the hardness decreases, making it undesirable as a denture base, and the mechanical strength also decreases.

In the present invention, the argylnisder of acrylic acid or methacrylic acid has an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms. This is because when the number of carbon atoms exceeds 5, the affinity of the fluorine-containing copolymer decreases.

The mixing amount of the acrylic acid or methacrylic acid alkyl ester polymer or copolymer is 30 to 95% by weight, and the preferred mixing ff1 is 40 to 90% by weight, more preferably 40 to 70% by weight. This is because if it is less than 30% by weight, the hardness of the denture base will be low, and the mechanical strength will also decrease, and if it is more than 95% by weight, the improvement in mechanical strength will be reduced. These acrylic acid or methacrylic acid alkyl ester polymers or copolymers may be used in combination. Among these polymers or copolymers, polymethyl methacrylate is most preferred.

The denture base of the present invention can be easily obtained by molding a mixture of these resins into the shape of a denture base. 5) and at least one kind selected from methacrylic acid alkyl esters (alkyl group having 1 to 5 carbon atoms)! It is preferable to polymerize and mold a mixture containing 30 to 95% by weight of No. 13 in a mold.

If the amount of fluorine-containing copolymer is small, the mixture with alkyl acrylate, etc. will not mix uniformly and form a putty, so in this case, it is necessary to graft alkyl acrylate, etc. to the fluorine-containing copolymer. It is preferable to uniformly mix the polymerized copolymer by adding it to the fluorine-containing copolymer and acrylic acid alkyl ester mixture. When the amount of the fluorine copolymer is large, it can be mixed into a putty as usual and easily loaded into a mold.

These acrylic acid alkyl esters or methacrylic acid alkyl esters have good polymerizability and are almost completely superimposed within the mold. Therefore, the composition of the mixture is directly equal to the mixing ratio of the polymer. Polymerization and molding in a mold are carried out in the same manner as in a conventional method for manufacturing a denture base using an in-mold polymerization mold of an alkyl acrylate polymer.

In the present invention, the mixture can be polymerized using a conventional polymerization initiator. At that time, as a polymerization initiator, benzoyl peroxide (hereinafter referred to as BPO) or dithered peroxide (hereinafter referred to as DTB) is used as a polymerization initiator.
Organic peroxides having a long half-life at room temperature, such as P), are preferred.

The denture base of the present invention has excellent mechanical strength, particularly impact strength. The impact strength can be measured by cutting off the resulting denture base, or
Or, for small specimens made of the same material, use the Dynstat method (D T N 53453 or B S 13
30-1946 test method).

The impact strength of the denture base of the present invention is 0.7 kg·cm S, preferably ρ, 7 rb·cm or more. Since the impact strength of the conventional denture base made of alkyl acrylate polymer is 0.5 to 9 cm or less, it can be seen that the impact strength of the denture base of the present invention is improved.

The present invention provides at least one alkyl ester of acrylic acid or methacrylic acid containing a fluorine-containing copolymer.
Because it is made of a mixture of polymers or copolymers of different monomers, it has excellent mechanical strength, especially impact strength.
There is no possibility of fatigue and breakage during use.

This will be further explained below using examples.

Example 1 A 10% by weight solution of methyl methacrylate was prepared using a fluorine-containing terpolymer consisting of 50 parts by weight of vinylidene fluoride, 30 parts by weight of chlorotrifluoroethylene, and 20 parts by weight of ethylene. A powdery polymer was prepared by suspension polymerization in 3 times the amount (weight ratio) of water. 10 gr of the obtained polymer and 10 gr of a mixture of the above fluorine-containing terpolymer/methyl methacrylate in a blending ratio of 10/90 were blended, and penzoyl peroxylide (BPO) was added as a polymerization initiator to methacrylic acid. A putty-like mixture was obtained by adding 1% by weight based on methyl. Add this putty-like mixture to 50x5
The polymer of Example 1 was obtained by press molding at 90° C. for 30 minutes using a metal frame of 0×2 mm. The impact strength of the obtained polymer was measured by the Dynstat method (D T N 53453). The results are shown in Table 1.

Examples 2 to 6, Comparative Example 1 In Examples 2 to 6, the same fluorine-containing terpolymer and methyl methacrylate as in Example 1 were blended in the proportions shown in Table 1 to form a putty-like mixture, which was then polymerized. The polymers of Examples 2 to 6 were obtained in the same manner as in Example 1 except that the impact strength was measured in the same manner as in Example 1. The results are shown in Table 1.

In addition, as a comparative example 1, the impact strength of a polymer of methacrylic acid meburu Kodoku without blending with a fluorine-containing copolymer was measured in Example 1.
It was measured in the same manner as above and shown in Table 1.

As shown in Table 1, it can be seen that when the amount of the nitrogen-containing copolymer is within the range of the present invention, the impact strength is significantly improved and the mechanical strength is excellent. .

Example 7 In Example 3, the amount of polymerization initiator BPO used was 0.5.1 ft3% based on methyl methacrylate, and 200 c
Seal the container in a glass container and let it stand for 5 hours at room temperature.The putty-like mixture is inserted into a plaster mold of the maxillary denture base made in advance, and heated at 100℃ for 60 minutes while keeping the container under control. A denture base was prepared by heating and polymerizing a putty-like mixture having a fluorine-containing copolymer/methyl methacrylate blending ratio of 30/70 in the same manner as in Example 1, except that the polymerization was performed under the same polymerization conditions as in Example 3. . The impact strength of the obtained denture base polymer was measured in the same manner as in Example 1, and the V# impact strength was 2.4 kg cm.
It had excellent mechanical strength. Furthermore, a denture base with an excellent appearance was obtained by removing it from the plaster mold and polishing it. A practical test of durability was conducted using this denture base on a 63-year-old man. As a result, it was confirmed that even after five years had passed, Tatsutsune Kito was not recognized.

Example 8 Vinylidene fluoride 50 parts, power 1 nap [10 parts [J]
30g of ternary fluorine-containing copolymer consisting of 2 parts of pyrene, 2 parts by weight of tetraph [10-L], 1 part of BPO with a polymerization initiator, and 1 part of normal zo[]pyr methacrylate. The mixture was mixed in a 200cc glass container in the same manner as in Example 7, except that 70g of normal propyl methacrylate containing 0.5% by weight was used, the mixture was sealed tightly, and left to stand at room temperature for 5 hours to form a putty-like mixture. was prepared, inserted into a plaster mold of a mandibular denture base made in the same manner as in Example 7, and heated and polymerized under pressure under the same conditions as in Example 7 to obtain a denture base. As a result of measuring the m-impact strength of the polymer material of the denture base, the impact strength was 2.4 kg·cm, indicating excellent mechanical strength. Furthermore, a denture base with an excellent appearance was obtained by removing it from the plaster mold and polishing it.

A practical durability test was conducted using this product on a 63-year-old man. As a result, it was confirmed that no abnormality was observed even after one year had passed.

Claims (3)

[Claims] (1) 5 to 70% by weight of fluorine-containing copolymer, acrylic acid alkyl ester (alkyl group has 1 to 5 carbon atoms) and methacrylic acid alkyl ester (alkyl group has 1 to 5 carbon atoms)
A denture base having excellent mechanical strength comprising 30 to 95% by weight of a polymer or copolymer of at least one monomer selected from the following. (2) The fluorine-containing copolymer is composed of two or more monomers selected from vinyl fluoride, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, and hexafluoropropylene. The denture base according to claim (1). (3) 5 to 70% by weight of fluorine-containing copolymer, acrylic acid alkyl ester (alkyl group having 1 to 5 carbon atoms) and methacrylic acid alkyl ester (alkyl group having 1 to 5 carbon atoms)
1.) A method for producing a denture base, comprising polymerizing and molding a mixture of 30 to 95% by weight of at least one monomer selected from the following in a mold.