WO2013050015A1

WO2013050015A1 - Elastomer material

Info

Publication number: WO2013050015A1
Application number: PCT/DE2012/000954
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: DE102011115061A1

Abstract

The invention relates to an elastomer material having the following general composition: (1a) low-molecular QM resins containing vinyl- and ethoxy groups, solid or liquid, mixed with polyorganosiloxanes having at least two terminal and/or lateral unsaturated groups in the molecule, (1b) mixtures of QM-resins in polyorganosiloxanes having at least two terminal and lateral unsaturated groups in the molecule, (2) polyorganohydrogensiloxanes comprising at least two SiH-groups in the molecule, (3) precious metal catalyst. The claimed material is used in the acoustic field, for example for noise protection and for swimming protection.

Description

Elastomeric material

The invention relates to materials and methods for manufacturing by means of 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 two 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

Fitting pieces complaints (for example

Pressure points) and impair the function of hearing aids (for example

Feedback). Consequently, it is important that the formulation is as low viscosity as possible, that is "well flowing", so that too

Undercuts and finest surface textures can be filled by the material and thus imaged.

CONFIRMATION COPY As a further method group for the production of earmolds, which works on the basis of digital data, use is made of layering methods, such as, for example, stereolithography. It is from US Pat. 4,575,330 discloses that low-viscosity, radiation-curable resins or resin mixtures for the production of three-dimensional objects by means of

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 in such a way 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 so 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 not completely cured molding is referred to in the art of stereolithography as a green compact, and the strength of this green compact, characterized by the modulus of elasticity and the bending 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

Deform stereolithography process under its own weight or during the post-curing, for example with a Xenonbogen- or

Halogen lamp, sag or can bend. Furthermore, due to the process, the green bodies are built on supporting structures, so-called supports. These supports must keep the green body stable throughout

Position manufacturing process, since the position of the green compacts not 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, such as

Silicone materials or highly filled composites, not or only very limited access. On the other hand, in the above-mentioned sense have low-viscosity, free-radical curing

Resin formulations for the generation of flexible ear molds only a low tensile strength and are therefore only for selected applications in the Hearing aid used. In addition, resins filled with metal particles are used for additive manufacturing technologies and subsequent

Laser direct structuring for the production of earmolds as a circuit carrier due to the sedimentation of the metal particles not

feasible.

The invention provides materials and a

Method available to solve the above problems.

The invention enables the use of soft elastic materials for the first time

Production of moldings, in particular earmolds, on the basis of digital data by ablative manufacturing processes, which were not suitable according to the prior art.

The invention relates to the production and

Use of polymerisable materials, in particular based on

Polyorganosiloxanes, which have improved processing properties compared to the prior art by adding special new raw materials and resins when used in abrasive manufacturing processes such as milling.

The invention particularly relates to silicones which are used in the field of hearing aid acoustics, examples being silicones for noise protection and silicones for swimming protection.

Indirect as well as direct methods are currently used for the production of noise and swimming protection earmoulds. Because the

Requirements on the wearing comfort are very high, the form faithfulness and fit accuracy of Silicone earmold of great importance. To be particularly suitable

addition-curing silicones have been shown which have only a low shrinkage and are therefore particularly dimensionally stable.

Addition-curing silicones according to the state of the art consist of the following raw materials (all or only some of them):

(la) polyorganosiloxanes having at least two unsaturated groups in the molecule (terminal and / or pendant); (lb) Low molecular weight vinyl and

ethoxy group-containing QM resins and / or mixtures of QM resins in polyorganosiloxanes according to (la);

(2) polyorganohydrogensiloxanes having at least two SiH groups in the molecule;

(3) polyorganosiloxanes without reactive groups;

(4) noble metal catalyst;

(5) reinforcing fillers, with loaded or unloaded surface;

(6) non-reinforcing fillers;

(7) oils or other plasticizers;

(8) other additives and conventional additives, auxiliaries and dyes;

(9) inhibitors. The compounds according to (la) are polyorganosiloxanes having terminal and / or pendant reactive groups with a viscosity at 23 ° C. of about 50 mPa s to 165

000 mPa s, preferably from 200 mPa s to 65 000 mPa s.

The compounds according to (1b) are low molecular weight vinyl and ethoxy group-containing

QM resins and / or mixtures of QM resins in polyorganosiloxanes according to (la) with viscosities of 150-65 000 mPa s The compounds according to (2) contain reactive SiH

Groups which build up the polymer in an addition reaction under noble metal catalysis with the compounds (1). The compounds according to (3) include the silicone

Oils which, like the compounds of (1)

Polyorganosiloxanes are, but for the

noble metal

Addition crosslinking reaction unreactive groups, such compounds are for

Example in. Noll "Chemistry and Technology of Silicones", Verlag Chemie Weinheim, 1968

described. The noble metal catalyst (4) is preferably one

Platinum complex, particularly well-suited platinum-siloxane complexes, as already described in US-A-3,715,334, US-A-3,775,352 and US-A-3,814,730. Reinforcing fillers according to (5) usually have a BET surface area of more than 50 m ² / g. These include, for example, fumed or precipitated silicas and

Silicon aluminum mixed oxides. The mentioned

Fillers may be obtained by surface treatment with, for example, hexamethyldisilazane or

Organosiloxanes or organosilanes be hydrophobic.

The non-reinforcing fillers according to (6) have a BET surface area of up to 50 m ² / g, these include the quartzes, cristobalites, diatomaceous earths, kieselgure, calcium carbonates, talc, zeolites, sodium aluminum silicates, metal oxide and

Glass powder. These fillers can also

as well as the reinforcing fillers be hydrophobic by surface treatment.

Examples of suitable compounds according to (7) are hydrocarbons, particular preference being given to paraffin oils.

Furthermore, as additives color pigments and other auxiliaries such as

finely divided platinum or palladium as

Be contained hydrogen absorber.

To control the reactivity, it may be necessary to use inhibitors (9). Such

Inhibitors are known and, for example, in US

A-3 933 880. In general, these are acetylenically unsaturated alcohols or vinyl-containing poly, oligo- and

Disiloxanes. The compositions are preferably formulated in two components in order to ensure storage stability. The total content of noble metal catalyst (4) is in the catalyst component A, the total content of SiH compound (2) is in the second, spatially separated from the first component component, the base component B.

accommodate. By mixing the two components A and B, the compositions cure in an addition reaction known as hydrosilylation.

The volume ratios of the two components A and B can be 10: 1 to 1:10. Particularly preferred are volume mixing ratios of 1: 1, 4: 1 and 5: 1 (base to catalyst component). Silicone earmolds as noise or swimming protection are usually worn over a longer period in the ear. The use of silicones in the field of noise and swimming protector earmolds is known because the silicones offer a wide range of mechanical and physical properties and have the further advantage that they have little or no toxic, sensitizing or allergenic potentials. This makes them for medical

Applications very well suited. The

Perfect fit of earmolds plays a special role.

Silicone earmolds according to the prior art are subjected, after curing in the machining process, to different post-treatments, such as, for example, milling, polishing, grinding, as well as constructional modifications such as, for example, milling. the

Attaching ventings (ventings) are in This form manually carried out consuming. Because of the special mechanical properties of the materials used for silicone earmolds as noise or swimming protection this is

Post-processing step problematic, the elastomeric properties cause poor workability, often to faulty

Leads products.

The following Table 1 summarizes by way of example the mechanical properties of silicone materials according to the prior art.

Example 1: translucent silicone material

(Comparative example)

Catalyst component (A)

1.9% by weight of vinyl-end-stopped polydimethylsiloxane having a viscosity of 200 mPa s

1.9% by weight of vinyl-end-stopped polydimethylsiloxane having a viscosity of 1000 mPa s

2.8% by weight of vinyl-end-stopped polydimethylsiloxane having a viscosity of 10000 mPa s

50.4% by weight of vinyl end-blocked

Polydimethylsiloxane with a viscosity of 65000 mPa s

8.9% by weight of a polydimethylsiloxane oil having a viscosity of 50 mPa s

% By weight of a paraffin oil 21.7% by weight of a fumed silica

(surface treated) with a BET surface between

150 m ² / g and 200 m ² / g

0.4% by weight of a platinum catalyst are introduced and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 minutes.

Basic component (B)

2.9 wt.% Vinylendgestopptes polydimethylsiloxane having a viscosity of 10,000 mPa s

49.6% by weight of vinyl end-blocked

Polydimethylsiloxane with a viscosity of 65000 mPa s

3.1% by weight of a polydimethylsiloxane oil having a viscosity of 50 mPa s

7.6% by weight of a paraffin oil

21.2% by weight of a fumed silica

(surface-treated) with a BET surface area between 150 m ² / g and 200 m ² / g 11.8% by weight of a polymethylhydrogensiloxane having an SiH content of 2.3 mmol / g are introduced and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 minutes.

Mixture of catalyst and base component (A

+ B)

50 parts of the catalyst component and 50 parts of the base component are from a

Double cartridge promoted and over a

static mixer mixed homogeneously.

This gives a cured specimen with a final hardness of 40 Shore A and excellent mechanical properties (tensile strength, elongation at break).

The processing of the cured specimen in an erosive manufacturing process (milling) on the basis of digital data does not succeed. The specimen is too elastic and that

Chip behavior and deformation during heating during machining leads to inaccuracies.

Example 2: opaque silicone material

(Comparative Example)

Catalyst component (A)

1.9% by weight of vinyl-end-stopped polydimethylsiloxane having a viscosity of 1000 mPa s 2.8% by weight of vinyl-end-stopped polydimethylsiloxane having a viscosity of 10000 mPa s

50.1% by weight of vinyl end-blocked

Polydimethylsiloxane with a viscosity of 65000 mPa s

8.9% by weight of a polydimethylsiloxane oil having a viscosity of 50 mPa s

12.0% by weight of a paraffin oil

21.7% by weight of a fumed silica

(surface-treated) with a BET surface area between 150 m ² / g and 200 m ² / g

0.3% by weight of white pigment (titanium dioxide)

Basic component (B)

1.8% by weight vinyl endstopped polydimethylsiloxane having a viscosity of 200 mPa s

1.8% by weight of vinyl-endstopped polydimethylsiloxane having a viscosity of 1000 mPa s

2.8% by weight vinyl endstopped polydimethylsiloxane having a viscosity of 10000 mPa s 48.1% by weight of vinyl end-blocked

Polydimethylsiloxane with a viscosity of 65000 mPa s

3.1% by weight of a polydimethylsiloxane oil having a viscosity of 50 mPa s

7.6% by weight of a paraffin oil

21.2% by weight of a fumed silica

(surface-treated) with a BET surface area between 150 m ² / g and 200 m ² / g

1.5% by weight of a blue dye

12.1% by weight of a polymethylhydrogensiloxane having an SiH content of 2.3 mmol / g are introduced and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 minutes.

Mixture of catalyst and base component

Double cartridge promoted and over a

static mixer mixed homogeneously.

This gives a cured blue, opaque sample with a final hardness of 40 Shore A and excellent mechanical properties

(Tear strength, elongation at break).

The processing of the cured specimen in an abrasive manufacturing process (milling) on the basis of digital data does not succeed. The specimen is too elastic and that

Example 3: translucent silicone material

(Comparative Example)

Catalyst component (A)

28.1 wt.% Mixture of QM resin in

Polyorganosiloxanes having a viscosity of 6000-65000 mPa s

4.9 wt.% Polydimethylsiloxane with

pendant vinyl groups with a viscosity of 5000 mPa s

45.5% by weight of vinyl end-blocked

Polydimethylsiloxane with a viscosity of 65000 mPa s

1.1 wt.% Of a polydimethylsiloxane oil having a viscosity of 50 mPa s

19.5% by weight of a fumed silica

(surface-treated) with a BET surface area between 150 m ² / g and 200 m ² / g

Base Component 24.6 wt.% Mixture of QM resin in

Polyorganosiloxanes with a viscosity of 6000 - 65 000 mPa s

47.6% by weight of vinyl end-blocked

Polydimethylsiloxane having a viscosity of 65000 mPa s 0.7 wt.% Of a polydimethylsiloxane oil having a viscosity of 50 mPa s

20.4% by weight of a fumed silica

(surface-treated) with a BET surface area between 150 m ² / g and 200 m ² / g

0.7% by weight of a polymethylhydrogensiloxane having an SiH content of 4.3 mmol / g 6.0% by weight of a polymethylhydrogensiloxane having an SiH content of 7.3 mmol / g are introduced and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 minutes.

Mixture of catalyst and base component

Double cartridge promoted and over a

static mixer mixed homogeneously.

This gives a cured specimen with a final hardness of 58 Shore A and outstanding mechanical properties (tear strength, elongation at break).

The processing of the cured specimen in an erosive manufacturing process (milling) on the basis of digital data does not succeed. The test specimen is too elastic and that

Table 2 summarizes the mechanical

Properties of the comparative examples together.

It is therefore desirable materials

to provide the simplicity of the

Use of silicones according to the state of

Technique with a special aptitude for

combine erosive manufacturing processes based on digital data. In particular, these novel materials should be readily usable in blanks already described above to provide elastomeric blocks for digital data ablation manufacturing processes.

Surprisingly, this succeeds with

formulations according to the invention of the following general composition:

(la) Low molecular weight vinyl and

Ethoxyl-containing QM resins, solid or liquid, mixed with polyorganosiloxanes having at least two unsaturated groups in the molecule (terminal and / or pendant)

(lb) Mixtures of QM resins in

Polyorganosiloxanes with at least two unsaturated groups in the molecule (terminal and / or pendant)

(2) Polyorganohydrogensiloxanes having at least two SiH groups in the molecule

(3) noble metal catalyst

The compounds according to (la) are clear-transparent base mixtures of the LSR 70XX type (XX denotes the Shore A hardness,

XX = 60 or 80, for example), as described by Momentive Performance Materials

(Leverkusen, Germany).

The compounds of (Ib) are mixtures of QM resins in polyorganosiloxanes having viscosities of 150-65,000 mPa s.

The compounds according to (2) contain reactive SiH groups which build up the polymer in an addition reaction under noble metal catalysis with the compounds (1).

The noble metal catalyst (3) is preferably a platinum complex, and particularly suitable are platinum-siloxane complexes as already described in US-A-3,715,334, US-A-3,775,352 and US-A-3,814,730 are.

Furthermore, as additives color pigments further aids such as

finely divided platinum or palladium as

Be contained hydrogen absorber. The compositions are preferably formulated in two components in order to ensure storage stability. The total content of noble metal catalyst (3) is in the catalyst component (A), the total content of SiH compound (2) is in the second, spatially separated from the first component component, the base component B to accommodate. By mixing the two components, the masses harden in one

Hydrosilylation known addition reaction.

The volume ratios of the two components can be 10: 1 to 1:10. Especially

preferred are volume mixing ratios of 1: 1, 4: 1 and 5: 1 (base to catalyst component).

The following embodiments serve to explain the invention in more detail, are very detailed and are not intended to limit the invention in any way.

Example 4: clear-transparent silicone material

(inventive)

Catalyst component (A)

47.1% by weight of clear-transparent basic mixture of the type LSR 7060 (A) 52.7% by weight mixture of QM resin in

Polyorganosiloxanes with a viscosity of 6000

65,000 mPa s 0.2% by weight of a platinum catalyst are introduced and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 minutes.

Basic component (B)

46.3% by weight clear-transparent basic mixture of type LSR 7060 (B)

52.5 wt.% Mixture of QM resin in

Polyorganosiloxanes with a viscosity of 6000

65,000 mPa s

1.2% by weight of a polymethylhydrogensiloxane having an SiH content of 4.3 mmol / g are introduced and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 minutes.

Mixture of catalyst and base component

Double cartridge promoted and over a

static mixer homogeneously mixed into a round blank.

Curing takes place in a pressure pot for 30 minutes

80 ° C and 4 bar, then is additionally annealed for one hour at 150 ° C. This gives a cured clear-transparent test specimen with a final hardness of 40 Shore A and good mechanical properties (tensile strength, elongation at break).

The processing of the cured specimen in an erosive manufacturing process (milling) on the basis of digital data succeeds very well. From the test specimen can on the basis of digital data with milling machines according to the state of

Technique very accurate, three-dimensional parts, for example, earmolds are produced.

Example 5: clear-transparent silicone material

(Invention)

Catalyst component (A)

72.0% by weight of clear-transparent basic mixture of type LSR 7080 (A)

27.9 wt.% Mixture of QM resin in

Polyorganosiloxanes with a viscosity of 6000

65,000 mPa s

0.1% by weight of a platinum catalyst are introduced and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 minutes.

Basic component (B) 72.0% by weight of clear-transparent basic mixture of type LSR 7080 (B)

26.8 wt.% Mixture of QM resin in

Polyorganosiloxanes with a viscosity of 6000

1.2% by weight of a polymethylhydrogensiloxane having an SiH content of 4.3 mmol / g are initially introduced and homogeneously mixed for 30 minutes. The mixture is then degassed in vacuo for 15 minutes.

Mixture of catalyst and base component

Double cartridge promoted and over a

static mixer homogeneously mixed into a round blank.

The curing takes place for 30 minutes in a pressure pot at 80 ° C and 4 bar, then is additionally annealed for one hour at 150 ° C. This gives a cured clear-transparent specimen with a final hardness of 70 Shore A and good mechanical properties (tear strength, elongation at break).

The processing of the cured specimen in an erosive manufacturing process (milling) on the basis of digital data succeeds very well. From the specimen can be based on digital Data with milling machines according to the state of

Example 6: gum-colored silicone material

(according to the invention)

Catalyst component (A)

72.0% by weight of clear-transparent basic mixture of type LSR 7080 (A)

27.9 wt.% Mixture of QM resin in

Polyorganosiloxanes with a viscosity of 6000

65,000 mPa s

Basic component (B)

72.0% by weight of clear-transparent basic mixture of type LSR 7080 (B)

25.0 wt.% Mixture of QM resin in

Polyorganosiloxanes with a viscosity of 6000

65,000 mPa s 1.2% by weight of a polymethylhydrogensiloxane having an SiH content of 4.3 mmol / g

1.8% by weight of a gum-colored

Color mixing (pink) are presented and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 minutes.

Mixture of catalyst and base component

Double cartridge promoted and over a

static mixer homogeneously mixed into a round blank.

The curing takes place for 30 minutes in a pressure pot at 80 ° C and 4 bar, then is additionally annealed for one hour at 150 ° C.

This gives a cured

gum-colored specimen with a

Final hardness of 70 Shore A and good mechanical properties (tear strength, elongation at break).

Technique very accurate, three-dimensional parts, for example, earmolds or gingiva masks are produced. Table 3 summarizes the mechanical

Properties of the comparative examples together.

Explanation:

BET is the abbreviation for a procedure for

Determination of the surface area of (porous) solids by gas adsorption, named after the inventors of the method Brunauer, Emmett and Teller QM resins: the name comes from the

Nomenclature of components of silicones, M denotes monofunctional groups, Q denotes tetrafunctional units (-Si (OR) 4). These Q units ensure strong branching and thus a spatial networking of the silicones

(= Resin) Basic mixture LSR 7060 (A)

or 7080 (A) denotes one

Momentive's raw material, which contains platinum catalyst, so it is a raw material that may only be added to the catalyst component (A).

Basic mixture LSR 7060 (B) or 7080 (B) refers to a raw material of Momentive, the crosslinker (SiH) contains, so it is a raw material, which only in the base component

(B) may be given.

Table 1: Mechanical properties of transparent

Silicone materials of the prior art

Material Manufacturer Tensile strength Elongation at break Tear strength

(DIN 53504) (DIN 53504) (DIN ISO 34-1)

Biopor-Dreve Otoplastik 2.5 - 3.0 MPa>300%> 10.0 N / mm AB ^® GmbH

25 shore

A

Biopor-Dreve earmould 4.0 - 4.5 MPa 250 - 300%> 15.0 N / mm AB ^® GmbH

40 Shore

A

Biopor-Dreve Otoplastics 6.0 - 6.5 MPa 200 - 250%> 17.5 N / mm AB ^® GmbH

70 Shore

A

Table 2: Mechanical properties of

Comparative Examples

Material Manufacturer Tensile strength Elongation at break Tear strength

(DIN 53504) (DIN 53504) (DIN ISO 34-1)

Comparative Example Dreve 4.4 MPa 325% 18.4 N / mm 1 earmold

GmbH

Comparative Example Dreve 3.8 MPa 258% 16.2 N / mm 2 earmold

GmbH

Comparative Example Dreve 6.5 MPa 229% 18.9 N / mm 3 earmold

GmbH

Table 3: Mechanical properties of

inventive examples

Material Manufacturer Tensile strength Elongation at break Tear strength

(DIN 53504) (DIN 53504) (DIN ISO 34-1)

Example 4 Dreve 3.9 MPa 305% 3.5 N / mm (according to the invention) Otoplasty

GmbH

Example 5 Dreve 7.3 MPa 158% 5.2 N / mm (according to the invention) Otoplastics

GmbH

Example 6 Dreve 7.3 MPa 158% 5.2 N / mm (according to the invention) Otoplasty

GmbH

Claims

Claims:

1. Elastomeric material having the following general composition:

(la) Low molecular weight vinyl and

Ethoxyl-containing QM resins, solid or liquid mixed with polyorganosiloxanes having at least two unsaturated groups in the

Molecule, terminal and / or pendent,

(lb) Mixtures of QM resins in

Polyorganosiloxanes with at least two unsaturated groups in the molecule, terminal and pendant,

(2) polyorganohydrogensiloxanes having at least two SiH groups in the molecule,

(3) noble metal catalyst.

2. Elastomeric material according to claim 1, characterized in that the material is formulated in two components, namely a catalyst component A with the total content of component (la), (lb) and the entire component (3), and a

Basic component B with the total content of component (2).

3. Use of the material according to claim 1 and / or claim 2 for the production of cured moldings for milled

Production of three-dimensional parts, in particular earmolds or gingiva masks.