MILLING BLANK FOR THE PRODUCTION OF MEDICAL-TECHNICAL MOLDED PARTS

Abstract

A milling blank for producing medical-technical molded parts made from a material produced from at least two components, wherein a first component A comprises a poly(alkyl methacrylate) polymer, and wherein a second component B comprises at least one alkyl acrylate monomere and/or one alkyl methacrylate monomer, in which the poly(alkyl methacrylate) polymer of component A is at least partially soluble, wherein the material comprises a flexibilizer as a further component, wherein the flexibilizer is selected from the group of citric-acid-based, adipic-acid-based, phthalic-acid-based or aliphatic esters.

Claims

1. A milling blank for producing medical-technical molded parts made from a material produced from at least two components, wherein a first component A comprises a poly(alkyl methacrylate) polymer, and wherein a second component B comprises at least one alkyl acrylate monomere and/or one alkyl methacrylate monomer, in which the poly(alkyl methacrylate) polymer of component A is at least partially soluble, wherein the material comprises a flexibilizer as a further component, wherein the flexibilizer is selected from the group of citric-acid-based, adipic-acid-based, phthalic-acid-based or aliphatic esters.

2. The milling blank according to claim 1, wherein component A comprises a poly(ethyl methacrylate) polymer (PEMA) or a poly(ethyl methacrylate) poly(methyl methacrylate) copolymer (PEMA-PMMA).

3. The milling blank according to claim 1, wherein component A is made up of 50%, with respect to the mass of component A of poly(ethyl methacrylate) polymer or copolymer.

4. The milling blank according to claim 1, wherein a mass fraction of at least 25% of the polymer powder is made of poly(ethyl methacrylate) polymer or poly(ethyl methacrylate) poly(methyl methacrylate) copolymer.

5. The milling blank according to claim 1, wherein component A comprises a catalyst, wherein the catalyst is present in a concentration of 0.25-1 percent by weight.

6. The milling blank according to claim 1, wherein the alkyl acrylate and/or alkyl methacrylate monomer of component B is at least one monomer of the group methyl methacrylate, ethyl methacrylate, ethyl acrylate, ethoxyethyl acrylate, tetrahydrofurfuryl methacrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate and/or isobornyl methacrylate.

7. The milling blank according to claim 1, wherein component B comprises at least 5% with respect to the mass of component B of the alkyl acrylate and/or alkyl methacrylate monomer.

8. The milling blank according to claim 1, wherein component B comprises at least two different alkyl acrylate and/or alkyl methacrylate monomers.

9. The milling blank according to claim 1, wherein the flexibilizer is present in a concentration of at least 5 percent by weight.

10. The milling blank according to claim 1, wherein the flexibilizer is 1,2-cyclohexane dicarboxylic acid diisononyl ester.

11. The milling blank according to claim 1, wherein the mass ratio of components A and B is 0.5-2.

12. The milling blank according to claim 1, wherein the material has a temperature-dependent memory effect, so that the material returns to its original shape after a deformation during heating.

13. A method for the production of a milling blank made of a material for medical-technical molded parts, comprising the steps: preparation of a component A comprising a poly(alkyl methacrylate) polymer, preparation of a component B comprising at least one monomer, in which the poly(alkyl methacrylate) polymer of component A is at least partially soluble, mixing of the components A and B and a flexibilizer, wherein the flexibilizer is selected from the group of citric-acid-based, adipic-acid-based, phthalic-acid-based or aliphatic esters, curing of the mixture.

14. The method for the production of a milling blank according to claim 13, wherein curing takes place at a temperature between 30° C. and 70° C. and/or over a duration of 20-90 minutes.

15. The method for the production of a milling blank according to claim 13, wherein the curing takes place in a pressure pot at an internal pressure of at least 3 bar.

16. The milling blank according to claim 5, wherein the catalyst is selected from the group consisting of an organic peroxide, barbituric acid, barbituric acid derivative and combinations thereof.

17. The milling blank according to claim 6, wherein the alkyl acrylate and/or alkyl methacrylate monomer is ethoxy ethyl methacrylate.

18. The milling blank according to claim 8, wherein the at least two different akyl acrylate and/or alkyl methacrylate monomers have a common percent by weight of at least 50% with respect to the mass of component B.

19. The milling blank according to claim 12, wherein heating comprises heating to a temperature of 37° C.

20. The method of claim 13, wherein the flexiblizer is 1,2-cyclohexane dicarboxylic acid diisononyl ester.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] An exemplary embodiment of the invention is explained in greater detail below. The FIGURE shows:

[0043] FIG. 1 Time-dependent relaxation of test bodies ( 5×5×80 mm) at 23° C. (.diamond-solid.) and at 37° C. (.square-solid.)

[0044] For the production of a milling blank for the production of medical-technical molded parts, a material produced from two components A and B is used, the compositions of which are shown in the below table.

TABLE-US-00001 Mass fraction, % Component A Poly(ethyl methacrylate) 99 1-benzyl-5-phenylbarbituric acid 1 Component B Ethoxyethyl methacrylate 49.73 Tetrahydrofurfuryl methacrylate 33.2 1,2-cyclohexane dicarboxylic acid diisononyl ester 16.5 Dilauryl dimethyl ammonium chloride 0.4 1% copper(II)-acetylacetonate solution in MMA 0.17

[0045] The two components according to the invention are mixed in a ratio A:B=100:75 with a spatula in a beaker and then cured in a pressure pot (Polymax, by company Dreve) at 50° C. and 6 bar for 45 minutes blister-free in a duplicating silicone mold. A milling blank with a diameter of 98 mm and a thickness of 18 mm is thereby obtained.

[0046] Test bodies of the dimension 5×5×80 mm are then generated from this milling blank by means of a milling machine (Otofab 1, by company pro3dure). Alternatively, medical-technical molded parts are manufactured based on three-dimensional data.

[0047] The test bodies are then tempered at 23° C. and at 37° C. for 24 h and then bent in the middle by 90° . The relaxation of the angle is subsequently recorded depending on the time at the two aforementioned temperatures in order to document the temperature-dependent memory effect. The results are shown in FIG. 1. It is thereby shown that the formulation according to the invention has a temperature-dependent memory effect, by means of which mold bodies, which are deformed at room temperature, almost return to their original shape from body heat.