WO2013050016A1

WO2013050016A1 - Blank for the material-removing production of ear adapters

Info

Publication number: WO2013050016A1
Application number: PCT/DE2012/000955
Authority: WO
Inventors: Martin Klare; Frank Gischer; Markus Kaiser; Thomas Veit
Original assignee: Dreve Prodimed Gmbh
Priority date: 2011-10-07
Filing date: 2012-10-01
Publication date: 2013-04-11
Also published as: DE102011115062A1

Abstract

The invention relates to a blank for the material-removing production of ear adapters. Said blank is made of a casting material consisting of two components, component A comprising a prepolymer and an iminooxadiazine-dione derivative and component B containing a chain extender mixture.

Description

Blank for the abrasive production of

Earpieces

The invention relates to a blank for

Production by removal of individually adapted to the contours of an ear canal

Earmolds based on a

multidimensional computer model of contours of earmolds.

Eartips are nowadays essentially made by 2 different methods

produced. When so designated PNP method (positive-negative-positive) takes the

Hearing acoustician in a first step, an ear impression (positive) for making a

Otoplastics (for devices worn behind the ear) or a shell (for devices worn in the ear). In a second step, using the

A negative mold (N) made in the following, in the following a radiation-curable,

cast low viscosity formulation and

is then exposed. The so made

Earpiece (positive) must be optimally adapted to the ear canal. Otherwise, would be inaccurate

Fittings cause discomfort (e.g., bruising) and affect the functioning of hearing aids (eg, feedback).

Consequently, it is important that the formulation is as low viscosity d. H. "Good fluency" is, so also undercuts and finest

Surface textures can be filled in by the material and thus imaged.

Another method group for the production of earmolds which works on the basis of digital data is the use of laminating methods such as e.g. the stereolithography used. It

CONFIRMATION COPY is known from US Pat. 4,575,330 that

low-viscosity, radiation-curable resins or resin mixtures for the production of

using three-dimensional objects

Stereolithography can be used.

Furthermore, it is known from US Pat. 5,487,012 and WO 01/87001 that stereolithography can be advantageously used for the production of ear pieces. In the stereolithographic process, three-dimensional objects are built up from a low-viscosity, radiation-curable formulation such that in each case a thin layer (about 0.0025-0.1 mm) of the formulation is precursor-hardened in a defined manner by means of actinic radiation such that the layer produced desired cross-sectional shape of the object at this point shows. At the same time, the generated layer becomes the one in the step before

hardened layer polymerized. The structure of the entire object can thus be accomplished with the aid of a computer-controlled laser system such as, for example, an Nd: YV0 ₄ solid-state laser (Viper si ² SLA system, 3D Systems, USA). The generated shaped body is optionally postcured, for example by radiation.

To the in the stereolithographic process

applicable resin formulations are made special requirements. In particular, the radiation sensitivity and the viscosity of the resin formulations, as well as the strength of the precured by laser hardening moldings are mentioned. This unfinished molding is referred to as a green compact in the art of stereolithography, and the strength of this green compact, characterized by Young's modulus and flexural strength, is referred to as Green strength. The green strength is an important parameter for the practice of stereolithography, since moldings with lower

Green strength during the

Stereo process under their own

Deform the weight or during the post-curing, for example, with a Xenonbogen- or

Halogen lamp, sag or can bend. Furthermore, the process due to the

Greenlings on supporting structures,

so-called supports, built. These supports must position the green compact stably during the entire manufacturing process, since the position of the green compacts is not determined by the

May change coating process.

Accordingly, the supports for a stereolithographic process must have minimal flexibility. For all these reasons, it is only very limitedly possible today to generate flexible earmolds based on 3-dimensional data. On the one hand, it is necessary for the stereolithographic process to use very low viscosity resins (<3Pas). For this reason, certain classes of materials, e.g. Silicone materials or highly filled composites, not or only very limited access. On the other hand, in the o.g. For low-viscosity, free-radically curing resin formulations for the generation of flexible ear molds only a small

Tear resistance and thus can only be used for selected applications in the hearing aid sector.

In addition, metal particle filled resins are used in additive manufacturing technologies

subsequent laser direct structuring to

Production of earmolds as Circuit carrier due to the sedimentation of the metal particles not feasible.

The invention is based on the object, span milling blanks for earmolds for

To provide, in which the surface of the blanks during milling not

smeared and the final product one of the

Temperature-dependent flexibility has to ensure that the earmold at

Room temperature in the hard elastic state in the auditory canal can be used and then significantly softened by body heat to ensure the highest possible comfort and

generate reduced feedbacks.

This object is achieved by a 2-component casting material for the production of the blanks, whose component A from a

Prepolymer and a

Iminooxadiazindionderivat exists and its

Component B contains a chain extender mixture. The two components A and B are described in more detail below. Components A contains a prepolymer, which consists of

Implementation of an excess of at least TMDI with at least two low molecular weight

aliphatic or cycloaliphatic

Hydroxyl compounds (m <200) with n = 2, at least one hydroxyl compound with n> 2 and a higher molecular weight polyol compound with n> 2 and a m> 400 and a metal catalyst

wherein the excess of moles of NCO groups to OH groups is 1 to 0.5 to 0.7, and an iminooxadiazinedione derivative having the formula

consists .

In this case, R is a Ci to Ci ₆ alkyl, in particular a Ci to Ci ₂ - alkyl, Ci ~ to Ci _6- Cycloalkyl and / or Ci to Ci6 Alkylcycloalkylrest, which has 1 to 4, preferably 1 or 2 Isocyanatgruppen ,

In the formulations according to the invention, for the reaction with at least TMDI as

aliphatic or cycloaliphatic

Diol compounds e.g. Ethylene glycol, di- and triethylene glycol, 1,2- and 1, 3-propanediol, di- and tripropylene glycol, 1,2- and 1,3- or 1,4-butanediol, 1, 5-pentanediol, dimethylhexanediol, 1, 6 Hexanediol, 2-methylpentanediol,

Neopentyl glycol, cyclohexane diol,

Dimethylolcyclohexane and 1, 12-dodecanediol can be used. As hydroxyl compound with n> 2, for example trimethylolethane,

Trimethylolpropane, trimethylolbutane, glycerol and the low molecular weight adducts of ethylene and / or propylene oxide can be used.

Preferred hydroxyl compounds with n> 3 are with four OH groups pentaerythritol and di-trimethylolpropane, with six OH groups, e.g. Di-pentaerythritol.

The abbreviation TMDI means

Trimethylhexamethylene diisocyanate, "m" means Molecular weight, with "n" is the number of hydroxyl groups (OH groups) in the molecule

for example, the compounds with n = 2 are diols,

NCO denotes the isocyanate group (N =

Nitrogen, C = carbon, 0 = oxygen).

Particularly preferred hydroxyl compound with n> 2 is trimethylolpropane.

As the polymeric polyols, polyester polyols, polyether polyols and polyalcohols containing both ether and ester groups are preferred in the claimed formulations. In this case, those hydroxyl compounds are preferred which have an equivalent weight of 100 to 800, particularly preferably 250 to 600 per hydroxyl group

have equivalent weight, the molecular weight m per hydroxyl group to understand n.

These are the preferred ones

Iminooxadiazinedione derivatives to asymmetric trimers of diisocyanates. These arise from the fact that three diisocyanate monomers combine via one isocyanate group and the second isocyanate group is retained. Of the

For the sake of simplicity, the substituted 6-imino-1,3,5-oxadiazine-2-diones used according to the invention are therefore also referred to below as diisocyanate trimers. According to the invention, diisocyanate trimers are preferably understood to mean those compounds which are formed by three identical monomers. Further iminooxadiazinedione derivatives used according to the invention are described, for example, in DE 19611849 A2, DE 19734048 A2 and by Richter and Mertes, color & lacquer 106

(9/2000) pages 60ff. called. The

Iminooxadiazinedione derivative according to the invention can be cured by isocyanate polyaddition similar to the monomeric isocyanates. In comparison to the symmetrical diisocyanate trimers, these have the same isocyanate reactivity.

Symmetric trimers are understood to be the corresponding isocyanuric acid derivatives which have a symmetrical arrangement of the ring atoms and substituents. The

asymmetric diisocyanate trimers according to the invention differ in comparison to the symmetrical variants by a much higher humidity and temperature stability and are lower viscosity. For example, the viscosity of the asymmetric trimer of HDI (hexamethylene diisocyanate) is lower by a factor of 2 compared to the symmetrical trimer variant.

The o.g. Properties are of special

Advantage for use in foundry materials for the production of milling blanks, since the lowest possible viscosity, the flow behavior of the material in e.g. Undercuts a form is guaranteed. Only then can the blank form optimally bubble-free with the casting material

be imaged. The increased humidity and temperature stabilities of the asymmetric trimers used are under

production-technical aspects

Advantage that e.g. under appropriate

Environmental conditions a more robust

Production process can be ensured. In component A of the invention

Casting material for the production of milling blanks is the prepolymer of at least 40 m%, preferably> 50 m% at least TMDI, at least> 5 m%, preferably> 10 m% of at least two

Prepared diol compounds and> 7.5 m%, particularly preferably> 10 m% of at least one polyol compound and a metal catalyst in the concentration range of 200-800 ppm, so that a molar ratio of NCO to OH of 1: 0.4 to 0.6, more preferably 1: 0.5. For the purposes of the invention, the prepolymer thus produced is mixed with at least one asymmetric trimer> 5 m%, preferably> 10 m%, based on the total component A. In this case, the inventive

Component A has a viscosity <17.5 Pas at 23 ° C, preferably <12.5 Pas and more preferably <10 Pas. Where m%

"Mass percentages".

Furthermore, the component A described above with a chain extension mixture B

be implemented. Component B consists of at least two low molecular weight (m <250) aliphatic or cycloaliphatic

Diol compound with n = 2 and at least one higher-functional hydroxyl compound with n> 3.

In the formulations according to the invention may preferably be used as aliphatic or cycloaliphatic Diolverbindungen eg ethylene glycol, di- and triethylene glycol, 1,2- and 1, 3-propanediol, di- and tripropylene glycol, 1,2- and 1,3- or 1,4-butanediol , 1,5 pentanediol, dimethylhexanediol, 1, β-hexanediol, 2-methylpentanediol, Neopentyl glycol, cyclohexanediol and

Dimethylolcyclohexane be included. When

Hydroxyl compound with n> 2, for example, trimethylolethane, trimethylolpropane,

Trimethylolbutane, glycerol and the

low molecular weight adducts of ethylene and / or propylene oxide can be used. preferred

Hydroxyl compounds with n> 3 are with four 0H groups pentaerythritol and di-trimethylolpropane, with six OH groups, e.g. Di-pentaerythritol.

Particularly preferred hydroxyl compounds with n = 2 are pentanediol and with n> 2

Trimethylolpropane.

As catalysts for the Urethanreakt ion, various organotin compounds can be used. These include catalysts such as

Dibutyltin oxide, dioctyltin oxide,

Dibutyltin glycolate, diacetate, dilaurate, maleate, dilauryltin diacetate,

Dibutyltin maleate ester, di-n-octyltin maleate ester,

Dibutyl tin alkyl mercaptide,

Dibutyltin mercaptoester, tributyltin laurate and di-n-octyltin carboxylates. Particularly preferred, taking into account

medical field of application and the toxicological effects, tin-free

Metal catalysts such as e.g.

Single metal catalysts based on zinc or bismuth carboxylates or mixed catalysts, as described e.g. commercially available under the name Borchi Kat from Borchers. These are compared to the o.g. Tin compounds for the medical sector advantageously

to use, for example in the case of Dibutyltin dilaurates during its production in side reactions, impurities

triorganic tin compounds, which are associated with high toxicological potential. Furthermore, there is a not yet fully clarified immunotoxic potency of the dibutyltin compound. The catalysts can be used both in the component A or in the chain extender mixture. The chain extender mixture according to the invention (component B) consists of at least two low molecular weight (m <250) aliphatic or cycloaliphatic diol compound with n = 2 with at least> 40 m%, preferably> 50 m% and particularly preferably> 60 m% in and at least one

higher-functional hydroxyl compound with n> 3 with> 10 and preferably> 20 m% based on the total component b.

Below is a comparative example and the examples of use of the o.g.

formulations according to the invention.

Example formulation 1

Preparation Example Polyisocyanate (A Component) Into a thoroughly dried 0.25 L

Three-necked round bottom flask apparatus

Nitrogen introduction is 5.97 g

Hexamethylene diisocyanate and 66.97 g of TMDI isomeric mixture submitted. After addition of 0.03 g of dibutyltin dilaurate, the mixture is added

Nitrogen atmosphere and vigorous stirring to 90 ° C heated. Within 30 to 60 minutes then a homogeneous mixture of 6.82 g of 1,5-pentanediol, 7.73 g of 1, 6-hexanediol, 1.1 g of 1,1,1-trimethylhexanediol and 11.41 g of a linear Bifunctional polyester (eg Oxyester T1136, Evonik) added dropwise by means of a dropping funnel so that the temperature over time increases to 100 to 110 ° C. Subsequently, the resulting, viscous prepolymer is allowed to

Completing the reaction for 30 to 60 minutes at 100 to 110 ° C to react. Then the mixture is cooled to room temperature. The isocyanate content of the A component thus prepared is 16.8% by mass. The viscosity of the

Adduct is at 23 ° C 16.8 Pas.

Production Example Chain Extension Mixture (B Component)

In a 0.25 L three-necked round bottom flask apparatus are 10.19 g of 2, 5-dimethyl-2, 5-hexanediol, 31.96 g of 1, butanediol, 10.07 g of 1, 5-pentanediol, 19.95 g 1, 6 Hexanediol and 27.83 g of 1, 1, 1-trimethylolpropane submitted. Under nitrogen atmosphere, the mixture is heated to 70 ° C and stirred until a clear, homogeneous solution

originated. The hydroxyl content of the so

produced B component is 34.0% by mass. The viscosity is 0.3 Pas at 23 ° C.

Alternative production

Alternatively, the described polyisocyanate (A component) can be prepared without a catalyst. For this purpose, the temperature after addition of the hydroxyl-containing mixture and

Completion of the described reaction times in addition for 1 to 2 hours at 120 ° C.

held. The catalyst is then added to the B component. Example formulation 1 does not contain an asymmetric iminooxadiazine dione derivative.

Accordingly, for the A component of the

For example, a viscosity of 18.4 Pas is determined. It follows that the material can only be used to a limited extent as casting plastic. Furthermore, an HDI monomer was used to prepare the polymer as an NCO component. As described above, this is undesirable under toxicological and production-technical aspects.

Table: Overview of the composition of the prepolymer of

Example Formulations 1 to 4

Example formulation 1 2 3 4

1, 6-hexamethylene diisocyanate, m% 5, 97 0, 00 0, 00 0, 00

2,2,4- and 2,4,4-66,97,70,70,70,70,70,70

Trimethylhexamethylene diisocyanate, m-

1, 5-pentanediol, m-% 6, 82 7, 55 7.55 7.55

1, 6-hexanediol, m% 7.73, 8.55, 8.55, 8.55

1, 1, 1-trimethylolpropane, m-% 1.1 1, 07 1, 07 1, 07 linear, OH bifunctional 11, 41 12, 14 12, 14 12, 14th

Polyester, m-%

100 100 100 100

Organotin catalyst, ppm 300 300 300 0

Organobismuth catalyst, ppm 0 0 0 600

Molar ratio of OH to NCO 1: 1: 1:

: 0.43 0.50 0.50 0.50 Example formulation 2

Preparation Example Polyisocyanate (prepolymer) Into a thoroughly dried 0.25 L

Three-necked round bottom flask apparatus

Nitrogen introduction 70.7 g TMDI isomers are presented. After addition of 0.03 g of dibutyltin dilaurate, the mixture is added

Nitrogen atmosphere and vigorous stirring to 90 ° C heated. Within 30 to 60 minutes is then a homogeneous mixture of 7.55 g of 1,5-pentanediol, 8.55 g of 1, 6-hexanediol, 1.07 g of 1,1,1-trimethylhexanediol and 12.14 g of a linear Bifunctional polyester (eg Oxyester T1136, Evonik) added dropwise by means of a dropping funnel so that the temperature over time increases to 100 to 110 ° C. Subsequently, the resulting, viscous prepolymer is allowed to

Completing the reaction for 30 to 60 minutes at 100 to 110 ° C to react. Then the mixture is cooled to room temperature.

Production Example Polyisocyanate (A-component) For the preparation of the monomer-free, good

pourable polyisocyanate mixture (A component) are added to 86.0 g of the o. Prepolymer 14.0 g of a symmetrical polyhexamethylene diisocyanate (for example Desmodur N3300, Bayer) was added and the mixture was stirred until homogeneous. Of the

Isocyanate content of the A component thus prepared is 15.2% by mass. The viscosity of the adduct at 23 ° C is 11.0 Pas.

Production Example Chain Extension Mixture

(B component) In a 0.25 L three-necked round bottom flask apparatus are 10.45 g of 2,5-dimethyl-2,5-hexanediol, 32.78 g of 1,4-butanediol, 8.89 g of 1,5-pentanediol, 18.84 g of 1, 6-hexanediol and 29.04 g of 1, 1, 1-trimethylolpropane submitted. Under nitrogen atmosphere, the mixture is heated to 70 ° C and stirred until a clear, homogeneous solution

originated. The hydroxyl content of the so

produced B component is 34.2% by mass. The viscosity is 0.4 Pas at 23 ° C.

Alternative production

Alternatively, the described polyisocyanate (prepolymer) can be prepared without a catalyst. For this purpose, the temperature after addition of the hydroxyl-containing mixture and completion of the reaction times described additionally held at 120 ° C for 1 to 2 hours. Of the

Catalyst is then added to the B component.

Example formulation 2 contains no

asymmetric iminooxadiazinedione derivative.

Accordingly, for the A component of the

For example, a viscosity of 11.0 Pas is determined. It follows that the material as

Cast plastic can be used for the production of milling blanks, however, the mixture with the chain extender mixture difficult

is to perform. In particular, fine air bubbles are introduced during the mixing process in the material, either in a

Pressure pot must be removed or closed

Inhomogeneities in the material can unfavorably result. Furthermore, no HDI monomer was used to make the polymer as the NCO component. This is as described above toxicological and production engineering

Aspects desired.

Table 2: Overview of the composition of the components a

Example formulations 1 to 4

Example formulation 1 2 3 4

Prepolymer, m% 100 86 86, 89 86, 89 symmetrical HDI polyisocyanate, m% 0 14 0 0 asymmetric HDI polyisocyanate, m% 0 0, 00 13, 11, 13, 11

100 100 100 100

Proportion NCO, m-% 16, 8 15.2 15, 4 15, 4

Viscosity, Pas 18, 0 11, 0 9.4 9.4

Example formulation 3

Preparation Example Polyisocyanate (prepolymer) Into a thoroughly dried 0.25 L

Three-necked round bottom flask apparatus

Nitrogen atmosphere and vigorous stirring to 90

° C heated. Within 30 to 60 minutes is then a homogeneous mixture of 7.55 g of 1,5-pentanediol, 8.55 g of 1, 6-hexanediol, 1.07 g of 1,1,1-trimethylhexanediol and 12.14 g of a linear bifunctional polyester (eg Oxyester T1136,

Fa. Evonik) by means of a dropping funnel so

added dropwise that the temperature over time to 100 to 110 ° C increases. Subsequently, the resulting, viscous prepolymer is allowed to Completion of the implementation for 30 to 60

Reactivate for a few minutes at 100 to 110 ° C. Then the mixture is cooled to room temperature.

pourable polyisocyanate mixture (A component) are added to 86.89 g of the o. Prepolymer 13.11 g of an asymmetric polyhexamethylene diisocyanate (for example Desmodur XP2410, Bayer) was added and the mixture was stirred until homogeneous. Of the

Isocyanate content of the A component thus prepared is 15.4% by mass. The viscosity of the adduct at 23.degree. C. is 9.4 Pas.

Production example chain extender mixture (B component)

In a 0.25 L three-necked round bottom flask apparatus are 10.45 g of 2,5-dimethyl-2,5-hexanediol, 32.78 g of 1,4-butanediol, 8.89 g of 1,5-pentanediol, 18.84 g of 1, 6-hexanediol and 29.04 g of 1, 1, 1-trimethylolpropane submitted. Under nitrogen atmosphere, the mixture is heated to 70 ° C and stirred until a clear, homogeneous solution

originated. The hydroxyl content of the so

produced B component is 34.2% by mass. The viscosity is 0.4 Pas at 23 ° C.

Alternative production

Alternatively, the described polyisocyanate (prepolymer) can be prepared without a catalyst. For this purpose, the temperature after addition of the hydroxyl-containing mixture and completion of the reaction times described in addition to Kept at 120 ° C for 1 to 2 hours. Of the

Catalyst is then added to the B component.

Example formulation 3 contains a

asymmetric iminooxadiazinedione derivative.

Accordingly, for the A component of the

For example, a viscosity of 9.4 Pas determined.

It follows that the material as

Giesskunststoff for the production of milling blanks can be used well and the mixture with the chain extender mixture is easy to perform. Furthermore, no HDI monomer was added to the

Preparation of the polymer used as NCO component. This is as described above under toxicological and technical production

Aspects desired.

In Fig. 4 is the time-dependent

Viscosity curve of the components a of

Example Formulation 2 and 3 at

Environmental conditions shown. These variants differ essentially in that formulation 2 uses the symmetrical trimer variant of HDI and formulation 3 dis asymmetric variant. From the picture you can see that the

Viscosity increase advantageously less for the asymmetric variant occurs. This is a significant advantage in terms of production technology. Table 3: Overview of the composition of the components b

Example formulations 1 to 4

Example formulation 1 2 3 4

1, 4-butanediol, m-% 31, 96 32, 78 32, 78 32, 78

1, 5-pentanediol, m-% 10, 07 8,89 8,89 8,89

1,6-hexanediol, m-% 19, 95-18, 84-18, 84-18,84

2, 5-dimethylhexane-2,5-diol, m-% 1 10, 19 10, 45 10, 45 10.45

1,1 _/ 1-trimethylolpropane, m-% 27, 83 29, 04 29, 04 29, 04

100 100 100 100

Proportion OH, m-% 34, 0 34.2 34.2 34.2

Viscosity, Pas 0.3 0.4 0.4 0.4

Example formulation 4:

Preparation Example Polyisocyanate (prepolymer) Into a thoroughly dried 0.25 L

Three-necked round bottom flask apparatus

Nitrogen introduction 70.7 g TMDI isomers are presented. After adding 0.06 g of organobismuth catalyst (e.g., Borchi Kat 24, Fa.

OMG Borchers) the mixture is submerged

Nitrogen atmosphere and vigorous stirring to 90

Fa. Evonik) by means of a dropping funnel so

added dropwise that the temperature over time to 100 to 110 ° C increases. Then you leave the resulting, viscous prepolymer for

Completion of the implementation for 30 to 60

pourable polyisocyanate mixture (A component) are added to 86.89 g of the o. Prepolymer 13.11 g of an asymmetric polyhexamethylene diisocyanate

(for example Desmodur XP2410, Bayer) and the mixture is stirred until homogeneous. Of the

Production example chain extender mixture (B component)

In a 0.25 L three-necked round bottom flask, 4.75 g of 2,5-dimethyl-2,5-hexanediol, 14.88 g

1, 4-butanediol, 4.04 g of 1,5-pentanediol, 8.56 g of 1,6-hexanediol and 13.19 g of 1,1,1-trimethylolpropane. Under nitrogen atmosphere, the mixture is heated to 70 ° C and stirred until a clear, homogeneous solution

originated. The hydroxyl content of the so

produced B component is 34.2% by mass. The viscosity is 0.3 Pas at 23 ° C. Alternative production

Organobismuth catalyst is then added to the B component.

Example formulation 4 contains a

asymmetric iminooxadiazinedione derivative.

Accordingly, for the A component of the

For example, a viscosity of 9.4 Pas determined.

It follows that the material as

Giesskunststoff for the production of milling blanks can be used well and the mixture with the chain extender mixture is easy to perform. Further, no HDI monomer and no organotin compound were used to prepare the

Prepolymer used as NCO component. This is desirable as described above under toxicological and production aspects.

Table 4: Overview of the chemical-physical values of

Example Formulations 1 to 4

Example formulation 1 2 3 4

A component, m-% 83, 3 84.8 84.6 84, 6

B component, m-% 16.7 15, 2.15, 4.15, 4

Appearance specimen clear clearly clear

Shore hardness, 23 ° C 95 85 95 95

Shore hardness, 37 ° C 70 70 75 72

Shore hardness, 60 ° C 66 64 60 60

Tensile elongation,% 250 150 200 190

Tensile stress, MPa 40 25 31 25

Water uptake, μg / mm ^Λ 3 41.9 29.9 25, 3 28, 6 An overview of the example formulations and their chemical-physical values is given in Tab.l to 4.

The requests were made as follows. To produce a milling blank A and B component according to the in

Production examples given

Quantities mixed homogeneously in a suitable vessel.

The mixture is poured into a suitable and dry mold. The curing takes place

conveniently at elevated temperature (e.g., 60 to 80 ° C) and elevated pressure (> 4 bar) in a suitable pressure polymerization apparatus (e.g., Polymax, Dreve, Germany) for one hour. After cooling, this way for all

Variants obtained colorless and crystal clear milling blanks.

The viscosities were all determined according to DIN 53019.

2 g of substance were used per determination of the viscosity. The determination of

Viscosity was carried out by means of a cone plate

Test arrangement on a Bohlin rheometer of the type CVO 120 at 23 ° C.

The Shore hardnesses were determined according to DIN 53505. For this, a 15x15x15 mm specimen was prepared as described above. This was then indicated in Tab. 4

Temperatures stored for at least one hour. The Shore hardness was determined immediately afterwards by means of a Shore hardness hand-held measuring device from Zwick. The tensile elongation and the tensile stress were determined according to DIN 53504 on a standard rod S2.

To determine the mechanical parameters, a 2 × 200 × 200 mm specimen was prepared as described above. From this, the standard rods S2 (n = 5) were produced by means of a punching device. All tests were carried out on a universal testing machine from Instron, type 5565.

The water absorption was calculated according to DIN EN ISO 1567-

2000 determined.

In each case 10 round specimens with a diameter of about 15 mm and a thickness of about 1 mm were prepared as described above. The determination of the water absorption then took place according to DIN EN ISO 1567-2000.

Subsequently, as described above

Mill blanks manufactured with a diameter of 110 mm and a thickness of 25 mm and machined in a milling machine 3D-variomill 5 ^A from Dentona. It was possible to obtain earmolds from all blanks.

It can be seen from Tables 1-4 that by means of the formulations according to the invention a

Casting material for the production of milling blanks is provided, all

Requirements for a milling material for

Production of ear molds met.

In addition, with the inventive

Formulation obtained a material in the

Compared to the prior art represents a much higher stability in terms of moisture at a reduced toxicity to the user. For example, crystal clear milling blanks for ear molds can be obtained from the casting material, which can be cut to size through milling and grinding Special features of the ear canal and the

appropriate supply can be customized. Furthermore, this material has a temperature-dependent Shore hardness. This allows the earmold to be easily inserted into the room at room temperature

Auditory canal are pushed. In the

Body temperature of the wearer, the material "softer" and therefore nestles better to the ear canal

Sealing and thus lower

Feedback tendencies and a higher one

Carrying comfort achieved.

Claims

Blank for the abrasive production of

Ohrpassstücken, wherein the blank is made of a two-component casting material, characterized in that its component A of a prepolymer and a

Iminooxadiazindionderivat whose component B contains a chain extension mixture.

Blank according to claim 1, characterized

in that its component A, d consists of a prepolymer which consists of the reaction of an excess of at least T DI with at least two low molecular weight aliphatic or cycloaliphatic

Hydroxyl compounds (m <200) with n = 2,

at least one hydroxyl compound with n> 2 and a higher molecular weight polyol compound with n> 2 and a m> 400 and a

where the d excess of moles of NCO groups to OH groups is 0.5 to 0.7, and a

Iminooxadiazinedione derivative of the formula

consists . Blank according to claim 2 by

characterized in that the hydroxyl compound with n> 2 is trimethylolpropane.

Blank according to one of claims 2 or 3, characterized in that as polymeric polyols polyester polyols, polyether polyols and polyalcohols, both ether and

Contain ester groups.

Blank according to one of claims 2 to 4, characterized in that the

Hydroxyl compounds have an equivalent weight of 100 to 800 per hydroxyl group.

Blank according to claim 5, characterized

characterized in that the hydroxyl compounds have an equivalent weight of 250 to 600 per hydroxyl group.

Blank according to one of claims 1 to 6, characterized in that the

Imoniooxadiazinedione derivatives are asymmetric trimers of diisocyanates.

Blank according to one of claims 1 to 7, characterized in that the component B of at least two low molecular weight (m <250) aliphatic or cycloaliphatic

Blank according to claim 8, characterized

characterized in that the hydroxyl compound with n = 2 pentanediol and with n> 2 trimethylolpropane.