DE2739905A1 - Nose bridge pad glued on spectacle frame - made of a silicone resin resistant to perspiration and compatible to human skin - Google Patents

Abstract

In the parent patent a pad for mounting upon the bridge portion of a spectacles frame for rendering the wearing of spectacles more comfortable is made of a homogeneous material, has a smooth, solid surface, is resistant to ageing, abrasion-resistant in use, can be firmly bonded to materials normally used for mfr. of spectacle frames, and has Shore-D hardness 10-20 (according to DIN 53505). In this addn. silicone resin "SYLGARD" (RTM) No 186 by Dow Corning is claimed. This material is physiologically compatible with the human skin, resistant to perspiration and will not harbour bacteria. It can be mass-produced.

Description

PAD

The invention relates to a pad for resting in the area of the root of the nose of spectacle wearers wearing spectacle frames, which pad is made of a homogeneous material is, which has a closed, essentially smooth surface, in general - < on the use of glasses is resistant to aging, is wear-resistant in wearing, me permanently bondable to the material used for spectacle frames is, can be produced translucent and measured according to DIN 53 505 a Shore D hardness from 10 - 20 has according to patent application P 25 45 683.1).

According to the main patent, the following difficulties exist: 1. The deceptive Area is small.

2. It is not possible with practical and economical methods the shape of the pads can be individually adapted to the shape of the nose.

3. The glasses are a prosthesis that is only used during sleep hours is filed.

4. Especially when the diopter is high, the glasses are in the front difficult, because then the glasses are thick.

5. Children and some adults as well as all Asians have a flat Root of the nose. If you support your glasses on it, then according to the wedge laws the contact pressure is many times higher than the weight of the glasses to be supported.

6. Many people have sensitive skin and can tolerate the weight the glasses not even if the nose has a convenient shape to support it.

7. People sweat the most under the pad. This has a whole Number of negative consequences: a The skin becomes even more sensitive.

b The connection between glasses and head deteriorates, i.e.

the glasses don't fit so well when you shake your head, when wind forces z. B. attack while sailing, etc. The center of the lenses then gets possibly oscillatory from its target position and you can no longer see as well as before.

c The sweat also causes chemical reactions. There are e.g.

People whose sweat is able to use the platinum layer on glasses frames dissolve. But also in "normal" cases the sweat can come out of the pads material dissolve out. You then have to make sure that piping is damaging when it is removed Reactions occur and the by-products of further chemical reactions are harmful are.

8. It hurts a lot when you put on glasses with hard pads Blow and this blow is then transferred to the bridge of the nose. Once in a while one has to cry involuntarily.

9. Since the glasses and their parts cover the face which the characteristic part of the human being, high aesthetic demands are too fulfill. In principle, the pads must give the designer every fashionable freedom and not force him to make certain constructions.

10. The pads have to do their job equally at very low temperatures like at very high temperatures and maintain their properties.

11. The pads must not yellow because many people wear their glasses sometimes wear for decades.

12. The pad must not give bacteria a settlement area, let alone one Represent food for bacteria.

13. The pad must be capable of being mass produced and must be able to be glued.

14. The material must be producible with devices that are not too complicated be.

Many materials force because of the two's quick response time Components work quickly and react in the spray head when you does not work fast enough. However, breaks are at least always necessary when material is replenished.

15. The material should be heat-insulating, otherwise there will be thermal bridges partial frostbite can occur.

The object of the invention is to solve the above-mentioned problems quite substantially better to solve than was possible with the main patent.

According to the invention, this object is achieved in that the material the silicone resin Sylgard (registered trademark) No. 186 from DOW CORNING. is.

This resin is a silicone elastomer with high mechanical strength and is used as an embedding resin for potting connections, cable looms, used for printed circuits and components, but also for the production of injection-molded ones High-voltage clamps, for sealing and gluing and for assembling devices used.

The exact properties of the resin can be found in leaflet 07 - 347 - 03 of October 1971 by DOW CORNING, with the title "Information on materials for the electrical and electronic industry ".

This data is also taken from the “Guide to Choosing DOW CORNING Products for the electrical and electronics industry ". The excellent Advantages in the field of eyeglass optics are as follows: 1. The skin under the material stays much drier. Obviously the material is very permeable to water, vapor permeable, gas permeable.

There is obviously a good exchange of fluids.

2. The great purity of the material also results in just that Transparency that you need in glasses optics.

3. The material has a very high tear strength, so that Violations of the material make little difference to its durability.

4. No kind of sweat and no environmental influences can do with the pads to wear something. There is no leaching of substances and therefore also omitted the problem of detrimental secondary reactions.

5. Although silicone is in principle also a release agent, mon glue it with the adhesive RTV 732 from DOW CORNING.

6. The pads produced in this way have a very good fit on all of them possible varieties of human skin. For explanation one could refer to a similar one here Think effect like with surf boards, the base of which is waxed so that you can has a secure footing even in the water.

Together with the high tear strength, there is a high level of temperature stability from -650C to + 2000C.

8. The material has no filler, i.e. nothing can get out of it .the .

9. The material is available for processing with two liquid components to disposal. So - unlike with granules - you don't need the substance first cumbersome to liquefy and can therefore work with simple machines, whereby the kilo price of DM 65, -, which is high in itself, is partly made up for will.

10. The material also allows you to put the pads on at atmospheric pressure pours.

Therefore, the shapes are also simple and the pad cheaper. It is also not necessary to produce the high pressures necessary for injection molding will.

11. The material hardens so slowly that the mixing machine for the two components can be cleaned easily and do not clog.

12. Even after being used for a long time, the pads still don't work No sticky surface at the beginning. This is especially true when used as a release agent a common liquid soap is used for the mold, e.g. in factories, toilets etc. is used. This is especially true if you use the WAYOLAN liquid soap Art. No. 6,332 from Enzian from 7418 Metzingen / West Germany was used.

13. Although this is a silicone rubber, achieved one with him without special attitude and using the starting materials, as they are delivered from the factory, a Shore D hardness in the range from 10 - 20, especially around 16. The Shore A hearing is 30, measured after the ASTM Test Method No. D 676.

Pads within the meaning of the invention are also notes or the like certain devices for placing the glasses on the nose.

Information on materials for the electrical and electronics industry MATERIAL DESCRIPTION The Sylgard resins 186 and 187 are new, high-strength. at room temperature curing silicone elastomers. They come in the form of a two component system Delivered in a pourable consistency.

Sylgard resin 186 is clear to translucent, while Sylgard resin 187 is black and opaque. Both resins have a three to four-fold increase Tear resistance compared to previously available, castable silicone elastomers on.

CHARACTERISTICS OF THE CROSSLINKED RESIN In addition to possessing high strength these silicone resins have excellent dielectric properties. The hardened Resins can be used within a temperature range of -65 ° to 250 ° C without post-curing are used in operation. Further material properties of these resins are none Shrinkage after curing at room temperature. Crosslinking in unlimited layer thickness No depolymerization when heated in the absence of air. Self-extinguishing No exolherms Heat development The crosslinking can be accelerated by supplying heat. Mechanical Stability and electrical resistance. High elongation of brucli. High density and elasticity Embedding resins SylgardR 186 and 187 (silicone elastomers with high mechanical strength) TYPICAL MATERIAL PROPERTIES These values are not intended for the purpose of relieving material claims certain) D.e Sylgard resins 186 and 187 differ - apart from theirs Color - not one another. Slygard Resin 186 is clear to translucent. Sylgard resin 187 is black.

In the state of attachment 186 187 Color of the hardener clear clear Basic viscosity in poise 800 850 Viscosity after adding 10 pph hardener in poise 0 hours. 450 500 2 hours 700 800 Pot life after adding 10 pph hardener> 2 hours Mechanical properties (after crosslinking 1 hour at 1500C) ASTM D-624 tear resistance. Sample shape B. kg / cm. 16 ASTM D-412 Elongation at Break, Sample Form C,% ......... 420 ASTM D412 Tensile Strength, Sample Form C, kg / cm² ....... 50 ASTM D-676 Hardness. Shore A. ....... . ................. 32 ASTM D-792 density ........................... .............. 1.12 ASTM D-1692 Flammability, self-extinguishing Content of non-volatile components in% 99.8 Electrical properties (after crosslinking 1 hour at 150CC) ASTM D-149 dielectric strength. kV / mm. . .. ... 23 ASTM D-257 Volume resistivity in ohms, cm 2x1015 ASTM D-150 dielectric constant at 100 Hz 3.01 at 100 KHz 3.00 ASTM D-150 dielectric loss factor -at 100 Hz 0.0009 at 100 kHz C, 001 ASTM D-257 Specific surface resistance in ohms. cm> 7x1016 The time taken for the viscosity to double after the addition of the resin. s / (? (- Cor ning'l ASl J (ienschatten Unit Test Verlahien No. 186 ralm When fully equipped, ak Color> gb Viscosity at 25'C Poise 0445 600 (51 Specific weight at 25rC 0 792 1.12 Eligibility month. 6th Pot life at 25c 1 | 1 hh 2 Hårlezeit / Tempelatur h / C 24125 0 1 tjjg engraving is at 25 "C 0 1218 1.43 E Radiation resistance (11 Megatad 200 Q Flash point (local GeIassI 'C 992 na. 5 water graduation. 7 days% at 25'CD 570 0.10 U Viscosity. Temperature coefficient t;, t Company stamp signature 'C 0 -65 to 2 m thermal conductivity (between 25 and 1 00Cl callcn-s (c1cmI Cenco-Fitch 5- X Thermal shock resistance 10 cycles MIL-16923C withstands Weight loss after 96 h1200.C / e Weight loss after 1000 h at 200 ° C Self-extinguishing 0 635. Yes Volume expansion coefficient cm '! Cm-'C Spe2;. '; Sch2 WAIT AT 25'C cal'g!' C 0.34 Corrosion Resistance MlL-S.23586 tu ns ul 2ugfestigfeit kplcrn '0 412 56 Elongation at break X 0412 480 Ilarity. Shore A 0 676 30 u 0 tear strength kr'cm O 624 18 Crumpled. 7 days at 25 nC% none 0 Velsprõdungspunt 'C 0 97/0 746 60 Tiel hardening 2.5 cm layer thickness ia Bleeding (Mrl.I.86601 na Consistency. unprocessed D 2t7 flowable arc resistance sec. D 495 Rel Oielekttizitats'nstante 10-Hr 0 924 D 150 3.01 o Real Oiektli7itatskoñstante 10ilr D 924'0 150 3.00 0 «Oiel. Loss taker at 1 0924.0150 0.0009 did Diel. Loss tractor at lg Hr 092410 150 0.001 Outchschlaglettigkeil kV: mm 0877i0 149 23 Specific resistance ohm. cm 0 1169! 0 257 2-10t Note All values are average values. obtained with the products concerned: they should not be used to (') draw up specifications for the INTENDED USE due to the increased mechanical strength values of Sylgard resins 186 and 187.

they are recommended, among others, for the following areas of application of connections autgespleiflle wiring harnesses. Pouring or embossing printed Circuits and components Injection-molded high-voltage terminals For sealing and gluing at Orl on site For the assembly of devices and devices Sylgard-Harz 187 is very suitable for use with heat shrinkable rubber hoses made of Sitastic type when assembling cable harnesses. The insulated with silicone rubber Cables remain highly elastic within the broad operating temperature range.

PREPARATION WORK AND CROSSLINKING Mix Sylgard Harze 186 and 187 are pourable polymers the hardener is a low-viscosity liquid. To activate 1 part of the hardener is mixed with 10 parts by weight of the resin. The viscosity the mixture is about half the initial viscosity. When, ... pay attention make sure that as little air as possible is included.

Lowering the viscosity The viscosity of the resin hardener system decreases by adding up to 10 O / o Sylgard 1330 - a non-reactive thinner - humiliate. If more than 10% thinner is used. pledges the danger of exuding. By adding Sylgard Thinner 1330, the mechanical properties and the Shore hardness is reduced and the elongation at break is increased.

Sygard Resin 184 and Harter can also be used as reactive diluents to reduce the viscosity of the Sylgard resins 186 and 187 are used. The advantage here is that the diluent and base resin are chemically linked to one another react. As a result, with any concentration of the diluent, no Exuding.

appear.

The mechanical properties of the thinned and hardened in this way Materials form a compromise between the mechanical properties of each Raw materials. Sylgard resins that contain fillers are not intended to be used as thinners be used because they impair the tear strength. The speed of response of Sylgard resins 186 and 187 does not become essential with the addition of the two thinners changes.

Compatibility tSylgard resins 186 and 187 also crosslink in contact with most of the materials used in electronic assemblies. Exceptions were butyl and chlorinated rubbers. some RTV silicone rubbers and the residues of amine catalysts from epoxy resin systems were found.

jOften surfaces. the | as a result of inhibition disturbances in cause Sylgard resins to cure properly by washing them off with Can be rendered harmless with solvents or by heating. Dissolve by heating the interfering reactive chemicals or they evaporate. Should this Methods to be unsuccessful. soa can sylgard masking protection 1332 to prevent of inhibition: to be used.

When using Sylgard resins, no signs of corrosion were observed on common metals such as copper.

Venting The air trapped in the ready-mixed batch must be removed to ensure a pore-free finished part. Enough for this evacuating the mixture for about 30 minutes at 50 torr absolute vacuum in usually off.

Repeated air supply will be in the first stage of evacuation the air bubbles that form are more easily broken. Before curing at elevated The de-aerated material should reach temperatures 10 minutes after switching off the vacuum be left standing.

so that residual traces of gases in the polymer can dissolve.

The containers used for evacuation should at least be that Have four times the volume of the mixture approach. to give room for expansion permit. The venting is done by reducing the viscosity of the batch by adding thinner relieved.

Prepare the containers and assemblies containers, molds or components.

that come into contact with Sylgard resins should be clean and dry be. Containers and molds that are used to process others, vulcanizing at room temperature Silicone rubbers, organic rubbers or plastics may have been used not without preceding. Thorough cleaning should be used, as there are traces of this Materials can inhibit the curing of Sylgard resins.

Glass and metal devices should be used for processing as far as possible will. to avoid any contamination.

Crosslinking After mixing, Sylgard resin 186 and 187 remain Processable for at least two hours (i.e. the viscosity is below the double the initial viscosity). There is a hardening time before further processing of the parts of 24 hours at 23 ° C is required.

Full crosslinking occurs after about three days at room temperature achieved. Sylgard resins can also be cured at elevated temperatures. They can be fully cured for 4 hours using one of the following schemes at 650C or 1 hour at 100 ° C or 15 minutes at 1500C.

Solid parts take a longer period of time. around the time for that Warming up to equalize the curing temperature.

Solid parts should usually be kept at the lowest possible temperature are cured so that the influence of heat contraction when the parts cool down at room temperature is as low as possible.

Thin layers of Sylgard resins harden quite well at room temperature slow. Gentle heating also accelerates the hardening of these thin layers when it has been at room temperature for some time.

Adhesion and demolding On other substrates than silicone rubbers becomes the best adhesion of Sylgard resins 186 and 187 using Dow Corning 90-198 RTV primers achieved.

Sylgard resins can normally be easily replaced by unprimed ones Remove luminescence from smooth surfaces except for glass. To redeem without .difficulties is d; e Use of a release agent attached.

Release agents that can be used are 2 to 5 percent aqueous solutions of bleach-free household detergents.

SHIPPING Sylgard Resins 186 and 187 come in packs of resin and Hardener sent in the correct mixing ratio. The net weights of the complete Packs are: 0.5 kg, 5 kg. 25 kg and 250 kg.

The @ enn @@@@ @nen information and data t @@@@ en on documents that we consider reliable.

Before any future use, you should thoroughly examine each use test and independently of the satisfactory deletion @@ @eugen. Usage suggestions are not to be used as an invitation to patent rights.

Claims (1)

Claim 1. Pad to rest in the area of the root of the nose of glasses troughs carrying glasses frames, which pad is made of a homogeneous material which has a closed, substantially smooth surface, in terms of the use of glasses is resistant to aging, is abrasion-resistant when worn, with the Materials used for eyeglass frames can be permanently bonded in a materially bonded manner is, can be made translucent and has a Shore D hardness measured in accordance with DIN 53 505 from 10 - 20 (according to patent application P 2545683. 1), characterized in that that the material is the silicone resin SYLGARD (registered trademark) No. 186 from DOW CORNING.