DE2321885A1 - POLARIZING EYE GLASSES - Google Patents

Description

Polarizing glasses

Addition to registration P 21 18 906.0

The invention relates to light-polarizing Yerbund lenses made of a polarizing element which is on each of its Planes has a layer that improves the adhesion between in situ formed lens components and the migration of the Lens components between the light polarizing element and the in situ polymerized lens components during the Production of the lenses prevented.

The polarizing eyeglasses according to the earlier application P 21 19 906 are particularly suitable for the production of im v / essential to all optical lenses of the desired diopter to adjust the eyes and correct the vision while the user enjoys the benefits of that can only be achieved with a light-polarizing material.

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"It's easy to see the many benefits that you get when using a tough plastic material optical quality for eyeglasses instead of glass. Arts-,-,; .-fabrics are much more resistant to breakage than glass, do not need any extremely high temperature during their manufacture and. In general, no complex grinding and polishing processes either, v / ie in most cases before the glass lenses are completed. Until the advent of modern transparent plastics optical qualities it has been very impractical to manufacture lenses from plastic materials as most are available Plastics are soft and easily scratched. V / o but tough thermosetting resins are used for lens manufacture these were difficult to handle in the case of material thicknesses such as those required for eyeglasses. To for the development of the lenses according to the above earlier application one needed corrective lenses for restoration and / or to aid vision, taking advantage of the light-polarizing Lenses that were made entirely of plastic material did not come into their own. The few available light-polarizing eyeglasses had glass elements between which a light-polarizing part was located. Obviously, however, this does not avoid all of the problems associated with glass lenses and the Difficulties in manufacturing such lenses and the extremely high scrap such lenses are extremely costly was.

According to the older proposal mentioned above, this happens Manufacture of synthetic eye lenses by introduction of a monomer for the plastic immediately on each side of a 3 light-polarizing element, which is in a Torrn is held. The curvature of the faces of the "se way." The lenses to be produced naturally result from the shape, the Molded parts, lying against the corresponding surfaces of the

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light polarizing element and at a certain distance from this. Since, as will be explained below, plastic lenses In general, grinding is carried out according to the relevant regulations, namely on the rear or concave Surface, the light-polarizing element should be as far as possible against the convex side of the lens so that the concave in situ polymerized part becomes much thicker than the convex part polymerized in situ.

A simultaneous proposal is to facilitate the fixation of a light-polarizing element in a flexible molding, provided with fittings or Protrusions around the periphery by such a predetermined distance between at least one surface of the light polarizer Element and the complementary molding to ensure.

It has now been found that in the context of the production of plastic lenses according to the application P 21 18 906 under In certain circumstances, a catalyst in connection with the monomeric material used to make the outer lens parts the monomeric material migrates into the light-polarizing element, which is part of the finished lens ^ and thereby detrimental "affects the light-polarizing element by balancing the dyes. In addition, in some Cases are found that plasticizers of the light-polarizing element migrate into the polymerizing monomer and this can soften and lead to a streaky and cloudy material. The monomer sometimes migrates into that light-polarizing element and leads to its deformation and curvature. According to the invention, a combination is now a "binding and a blocking layer are provided, which prevent the migration of catalysts, monomers or plasticizers, such as they are used in the production of composite lenses, prevents and ensures sufficient

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Adhesion between the individual parts of the composite material.

The invention "thus relates to light polarizing composite ophthalmic glasses and lenses, thawed from plastic, including a binding barrier layer that prevents migration of plasticizer, catalyst and monomers between the components of the lens. The invention also relates to a method for making such lenses in an economical manner Generally speaking, the invention now relates to the casting of plastic lenses in molds, preferably between rigid and flexible moldings, these flexible moldings preferably being cylindrical. A shaped light polarizing plastic is provided between layers of plastic monomers of optical quality in a form of flexible and rigid parts «It is heated so that an in situ polymerization of the monomers with simultaneous formation of a plastic composite lens with light polarizing Properties is effected. The essential aspect of the invention now lies in the fact that the light-polarizing element has a coating on both sides, which causes a secure connection between the light-polarizing element and the adjacent lens parts formed in situ and a migration of whiteners from the light-polarizing element into the monomers prevents, while at the same time prevents the monomer and any catalyst contained therein from migrating into the light-polarizing element.

The lenses produced according to the invention are then on optical laboratories are generally supplied semi-finished Condition for distribution. Because of the limitations of modern plastics grinding and polishing systems, the front or convex surface of the lens preferably in its final shape

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Cast in the course of production, so that this area is no Makes polishing or grinding treatment required. The concave surface is made with various curvatures to accommodate the Possibility to adapt accordingly to the nearsighted or visionary. If there is a specific Prescription or recipe, a cast lens that comes as close as possible is selected and then the exact one is selected Prescription the concave surface ground and polished. Of course, in some cases the lens shape can already be the desired specification without a grinding or polishing treatment correspond.

It is known that a certain amount of shrinkage occurs during polymerisation, although in some cases the lens surfaces do not correspond more to the shaped surfaces. Various possibilities are known to prevent this. For example, the Molded body made of flexible material, preferably made of a vinyl polymer, which in the sense of shrinkage also shrinks during the polymerization. This creates a ensures substantial conformity of the lens surfaces with the surfaces of the rigid form elements.

Any polymeric can be used within the scope of the invention light polarizing sheet material can be used. Transparent films made of polyvinyl alcohol are preferred oriented molecules of dehydrated polyvinyl alcohol, which essentially have the light-polarizing properties of the Are attributable to foil (US-PSS 2 173 304, 2 255 940, 2 306 108, 2 445 555, 2 453 186, 2 674 159). Furthermore are also Polyvinyl butyral and polyvinyl alcohol with dichroic coloring can be used.

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In a preferred embodiment according to the invention the light-polarizing material is enclosed in a sändwx-ch-shape between relatively thin layers of transparent plastic of optical quality that act as a carrier for the light polarizing Serve material. Cellulose acetate, for example, is suitable for this but y rat, methyl methacrylate, cellulose acetate and cellulose triacetate, of which cellulose acetate butyrate is preferred. the Bond between light polarizing element and polymer Carrier can take place in a known manner (US-PSS 3,620,868 and 3,588,216). This is followed by amination of a cellulose acetate butyrate carrier material with a polarizing film made of e.g. polyvinyl alcohol either by pre-coating the cellulose derivative s with a corresponding compound, such as cellulose nitrate, and laminating this pre-coated material in this way with the polyvinyl alcohol in press rollers with glue, such as a 2 $ igen Polyvinyl alcohol solutionj or by using the The surface of the cellulose acetate butyrate is converted into cellulose, the surface is precoated with polyvinyl alcohol and then the Lamination under pressure.

According to the invention, there are now binding intermediate layers applied to prevent the migration of various substances from. the light-polarizing element into the adjacent Monomers and at the same time from the monomers in the light polarizing Element. They are preferably applied, for example to the polymeric carrier material made of cellulose acetate butyrate for the light-polarizing element on the surface opposite to that directly connected to the light-polarizing element Element is laminated. This can be done before lamination with the light-polarizing element, e.g. with the help of a conventional slit application, which enables the application of a film with a thickness between 2 and 20 microns. For For this purpose one can of course use the most varied of materials use. Preferred is a nitrocellulose with a

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ASTMD301-56 viscosity of at least 600 seconds, preferably at least 2500 seconds ^ and a nitrogen content of about $ 12. The application material should preferably be more than Contains $ 20 nitrocellulose, "based on total resin weight the application mass. The binding barrier of the present invention can be made of nitrocellulose for $ 100. Preferably it contains a wetting agent, e.g. an organic titanate. However, it preferably contains at least one more resinous one Material which to a large extent prevents the penetration of components during lens molding. Examples for this are phenolic resins such as melamine formaldehyde, urea formaldehyde, Phenol-formaldehyde resins, polyhalogenated vinyl plastics such as polyvinyl chloride, polyvinylidene chloride, furthermore polyvinyl esters and acetals such as polyvinyl acetate, polyvinyl butyrate, also polyamides such as soluble nylons, polyacrylates such as polyacrylonitrile, polyethylene glycol dimethacrylate, soluble polyester resins and / or epoxy resins. Melamine-formaldehyde resins are preferred for this purpose.

The light-polarizing element in the context of the production of the composite lenses according to the invention is preferably preformed in accordance with the configurations of the plastic elements that are to be polymerized onto flexible sides. It is obvious that more extreme shapes of the convex and concave elements make a deviation in the shape of the light-polishing elements of the flat plate necessary. Exclude XL · now problems with the light refraction, the curvature of the liohtpolarisierenden element in about should be the same as the curvature of the convex surface of the lens. To prevent damage to the light-polarizing element during grinding and polishing of the concave surface, the lens should be as close as possible to the convex surface of the lens. The light-polarizing element is preferably preformed in accordance with conventional pressing techniques.

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When preforming the light-polarizing element, you can different diopters can be applied as indicated. These curvatures will generally be resolved adapt to the desired curvature which the outer or generally convex surface of the lenses is to assume.

During the manufacturing process, the monomer is used for the external. Layers of the lenses dissolved a catalyst. The ^ orm is preferably made up of rigid outer form elements, in particular made of glass. The front element sits on corresponding elevations of the light-polarizing element, which is on each. Surface is precoated with a binding barrier layer according to the invention. The whole is supported by a flexible part, e.g. 3. made of rubber, fixed. The flexible molded part is preferably cylindrical, but can in principle have any shape in cross-section and thus, for example, be rectangular, square or elliptical. Monomer with catalyst is introduced through the flexible area on one or both sides of the light-polarizing element with the aid of an injection syringe and the whole is then heated for a correspondingly long time until the polymerization has ended. Any plastic of optical quality can be used for the outer parts of the lenses. The only requirement is that the transition temperature of the second order is above the highest temperature that comes into question when using the lenses, e.g. 55 ⁰ C when using eyeglasses on average. Examples of useful monomers are 1,3-butylene glycol- dimethyl methacrylate, acrylonitrile, allyl methacrylate, trimethylol propane triacrylate, cyanoethyl methacrylate, bis-phenyl-A-dimethacrylate, methoxybutyl methacrylate, methyl methacrylate, diethylene glycol bisallyl carbonate, ethoxy methyl methacrylate, dimethyl methacrylate, ethylene glycol diacrylate, ethylene glycol-diacrylate, ethylene glycol-diacrylate, ethylene-glycol-diacrylate, dimethyl-glycol-diacrylate, dimethyl-glycol-diacrylate, cyanoethyl-methacrylate. Diethylene glycol biaallyl carbonate is preferred.

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The above polymers can be homo- or co-polymerized, to thereby increase their hardness, heat resistance and the like. As comonomers for the above monomers there are vinyl acetate, maleic anhydride, Ethylene glycol maleate, triallyl cyanurate or Diallyl phthalate.

If the monomer is only introduced on one side of the light-polarizing element, it should preferably have one or more bores in the immediate vicinity of the periphery in order to facilitate the transfer of the monomer into the other half of the mold. Since, as mentioned above, the concave part of the lens should be substantially thicker, the monomer is preferably introduced into this area and then flows into the convex area. The exact quantities required can easily be determined. In the usual way, possibilities for the escape of air must be provided.

Since thermosetting plastics are generally more wear-resistant than thermoplastic ones, they are preferred according to the invention. It has been found that using the preferred material, diethylene glycol bisallyl carbonate, has a cure time between about 8 and 16 hours for complete molding of the lenses is required.

In principle, any compatible catalyst can be used for the chosen monomer are used. Examples are diisopropyl percarbonate, benzoyl peroxide, azobisisobutyl nitrile, Methyl ethyl ketone peroxide and / or di-s-butyl percarbonate. Preferred becomes di-s-butyl percarbonate, in proportions based on monomer weight from about $ 2.5 to $ 4.5

In order to produce the desired color of the lenses, one can Apply dyes and these either adsorb on the surface of the outer plastic by being integral with it

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the initial monomer or by soaking or pouring into the plastic carrier for the light polarizing element. Even UV or IR absorbers can be used to adapt the visible light Dyes Q. the like. come into use.

The invention is explained further with reference to the figures.

Fig. 1 shows a side view in cross section of a light-polarizing lens element composed according to the invention. The parts 2 and 3 have concave and convex outer surfaces and are made of plastic, which in situ in Bond to the preformed light polarizing element. "The light polarizing element includes the light-polarizing film 4, transparent plastic films 5 as a carrier for the film 4 and thin binding barrier layers 6th

Fig. 2 shows the molding of a composite lens according to Fig. T. The elements 1, 2 and 3 are in the mold 11, which is composed of a flexible body S and the rigid elements 7, 7 '. The rigid element 7', which is intended to effect the convex surface of the lens to be manufactured is in direct contact with the noses 9 (see simultaneous application in our file number A-42 799). This arrangement is held together by the clamp 10, but any suitable means can be used for this purpose, such as integral compliant components or the like. The plastic starting material can be fed in any way between the light-polarizing element 1 and the rigid elements 7, 7 ¹ , but injection into the concave mold space through the elastic mold part with subsequent transfer of the monomer into the convex mold part via corresponding passages 12 is preferred which ensure a connection between the convex and the concave shape part in the assembled form. The elastic part

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the shape can generally be of any elastomeric material ". It is preferably with dioctyl phthalate plasticized polyvinyl chloride.

The plastic lenses according to the invention can be used as blanks or in unprocessed form and can, if necessary, then be sanded and polished, as you do with Kronglas. But as pointed out above, Grinding and polishing should preferably be done on the concave surface of the lens, as the preferred ones Embodiments almost the full range of possible prescriptions can be poured into the convex surfaces of the lenses, from which the selection is possible. To this to achieve in full is estimated. four to five hundred different convex shapes for everyone Apply necessary lenses for eye glasses. While the main purpose of the invention in the manufacture of eyeglasses can be seen, of course, flat lenses can also be cast for any purpose.

The invention is further illustrated by the following example.

example

A sheet of light-polarizing material in the form of a sheet of a tail hydrolyzed polyvinyl alcohol, which on both Pages a layer of about 125 to cellulose acetate butyrate and in which a light-dampening dye can be found, was coated on the outer surface by applying sole seat with a "layer of about 3 Aim thick, obtained from a Application mass of 3.34 l acetone, 4.4 l methanol, 240 cnr methyl cellosolve, 80 g nitrocellulose high molecular weight, 3.1 g Titanium di (acetylacetonate), 1.7 g triphenyl phosphate, 80 g melamine

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formaldehyde resin "U-Formite Mtt-56" and 4 g of maleic acid.

The maleic acid served as a polymerization catalyst for the phenol-formaldehyde resin. The titanium salt was a crosslinking agent for the cellulose. Triphenyl phosphate is a plasticizer. Acetone, methanol and methylcellusolv are solvents that are evaporated off after the layer has been applied. The light polarizing element with the adhesive barrier layer on each side was then pressed into a spherical configuration corresponding to about 6 diopters between heated plates and round, while cheese was produced on the perimeter and two holes were made on opposite sides of the perimeter. The holes and noses are generally made by customary molded parts that allow the appropriate shaping together with the trimming. This light-polarizing element thus obtained was then placed on a surface of a cylindrical resilient mold component, and an upper glass mold element was brought into contact with the tabs on the convex surface of the light-polarizing element. The surface configuration of the glass element essentially opposite to the surface of the light-polarizing element largely corresponds to this. A second glass element is attached to the elastic element on the side of the light-polarizing element opposite to the first rigid form element and the whole is then clamped together in the usual manner. About 3V2% by weight of di-s-butyl percarbonate as a catalyst was added to a predetermined amount of diethylene glycol bisallyl carbonate as a monomer and introduced through the elastic component into the concave mold space with the aid of an injection syringe. The whole was then transferred to an oven for 15 h and ^{heated from 32 to about 71 °} C. in the process. After this hardening time, the lens was removed from the mold and the lens was then tempered at about 93 ° C. for about 2 hours in order to compensate for tensions that could have been introduced during the molding process.

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The polymerization can be accelerated, inhibited or changed in some other way to achieve the desired result, as required Ensure hardening cycle for the lenses.

As mentioned, according to the invention, the most varied Lens shapes can also be produced nonplanar or biplanar.

Claims

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Claims (1)

Claims (Ί ,) Polarizing eyeglasses made of a light-polarizing element, optionally provided with a carrier layer on both sides, between two in situ polymerized plastic lens parts according to patent 2 118 906 characterized by an uninterrupted coating on each surface of the element, which ensures the adhesion between the Improved light-polarizing element and the lens parts formed in situ and prevents the migration of lens components to the light-polarizing element and vice versa. 2 · Eye glasses according to claim 1, characterized in that g e k e η η, that the coating is nitrocellulose, in particular crosslinked nitrocellulose, 3 · Eye glasses according to claim 2, characterized in that the coating additionally contains a melamine-formaldehyde resin, preferably in a weight ratio to nitrocellulose in the order of 1: 1. 8195 3 098Afi / D £ ß1