Method for producing a plastic article, plastic article, and polymerisable mixture

Abstract

One aspect of the invention relates to a method for producing a plastic article or semi-finished product from a polymerizable mixture of isocyanates and isocyanate-reactive components, wherein the mixture comprises at least one photochromic dye, at least one surface additive, an isocyanate component and at least one of the following components: - a poly(thio)urethane prepolymer produced from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is such that there is an excess of isocyanate-reactive groups in relation to isocyanate groups; - a poly(thio)urethane prepolymer produced from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is such that there is an excess of isocyanate groups in relation to isocyanate-reactive groups; - a thiol component; wherein the mixture contains at least one photobase generator, a photochromic dye and a surface additive. Further aspects of the invention relate to a plastic article or a plastic article provided with an additional layer, each produced by a method according to another aspect of the invention, as well as a polymerisable mixture.

Description

[0001] 120816P1423PC Rodenstock GmbH

[0002] P 2418 PCT - 1

[0003] Method for producing a plastic body, plastic body and polymerizable mixture

[0004] Description

[0005] The present invention relates to a method for manufacturing a plastic body.

[0006] Plastic bodies, especially plastic lenses, and preferably spectacle lenses, are generally manufactured from a polymerizable mixture or composition, often referred to as casting resin. Such a composition typically consists of plastic monomers and exists as a pourable or moldable mass. In the field of spectacle lenses with a refractive index of 1.6 or higher, poly(thio)urethanes are particularly widespread due to their excellent material properties. A poly(thio)urethane casting resin consists essentially of polyhydric isocyanates and isocyanate-reactive components, which are generally understood to be polyhydric alcohols or thiols. This casting resin mixture is poured, for example, to produce a plastic lens into a volume formed between two mold components arranged at a predetermined distance from each other.The structure is then cured by the application of energy; that is, the polymerizable composition or casting resin is polymerized, with the energy required for this usually being provided by thermal energy. In other areas, such as the application of functional coatings, particularly functional lacquers, to plastic lenses, these lacquers are generally applied to the plastic lens to be coated as polymerizable compounds before a thermally induced polymerization step takes place. When manufacturing plastic spectacle lenses by thermally induced polymerization, great care must be taken to ensure the uniform distribution of the supplied thermal energy, as failure to do so can result in products with inhomogeneous material properties, or, in the case of mass production, products with completely different material properties. 120816P1423PC Rodenstock GmbH.

[0007] P 2418 PCT - 2 - can be obtained. To ensure this level of care, elaborate convection ovens with lengthy heating programs lasting several hours or days are used. Operating these ovens for such a long period is typically associated with considerable energy costs.

[0008] Another difficulty lies in producing plastic lenses, preferably plastic spectacle lenses, with good photochromic properties, since the lenses or glasses must have excellent properties in terms of visual clarity, darkening depth after illumination with sunlight / UV light, brightening speed after the end of the exposure, durability of these photochromic properties in everyday use and surface hardness to prevent scratching.

[0009] EP 3 527 597 discloses polymerizable compositions in which photochromic properties are obtained through the interaction between surface additives, in particular poloxamers, and photochromic dyes.

[0010] The object of the present invention is therefore to provide a polymerizable mixture or composition in order to produce a photochromic plastic body, in particular a plastic lens, preferably a photochromic plastic spectacle lens with very good properties.

[0011] The problem is solved by a polymerizable mixture or composition and the associated process as claimed in the independent claims.

[0012] In particular, the use of a polymerizable mixture described herein in a process described herein, or the use of a polymerizable mixture described herein to form a plastic body described herein by a process described herein, is also protected. Preferred embodiments are the subject of the respective dependent claims. 120816P1423PC Rodenstock GmbH

[0013] P 2418 PCT - 3 -

[0014] One aspect concerns a polymerizable mixture, in particular a photopolymerizable mixture, preferably for a poly(thio-)urethane, comprising at least two of the following components:

[0015] A poly(thio-)urethane prepolymer prepared from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is such that there is an excess of isocyanate-reactive groups compared to isocyanate groups;

[0016] A poly(thio-)urethane prepolymer prepared from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is such that there is an excess of isocyanate groups compared to isocyanate-reactive groups; a thiol component; an isocyanate component; wherein the ratio of isocyanate groups to thiol groups / isocyanate-reactive groups is 0.95:1 to 1:0.95; and wherein the mixture additionally comprises at least one photobase generator, at least one surface additive, and at least one photochromic dye; and at least one photochromic center to which at least one polymer chain is bonded, preferably exactly one polymer chain, comprising at least 4, preferably at least 8, repeating units.

[0017] Using such a polymerizable mixture, photochromic plastic bodies made of poly(thio-)urethane can be produced or cast. In other words, such a (photo-)polymerizable mixture, a photopolymerizable poly(thio-)urethane casting resin mixture, can be used in the production of photochromic plastic bodies and / or the finishing of such plastic bodies, particularly in the application of additional layers, especially photochromic layers.

[0018] The mixture is characterized by the photobase generator, in particular by the fact that it can be cured, especially by irradiation with light, preferably UV light. Advantageously, this allows for accelerated curing, especially without the need for a conventional, time-consuming process. (Rodenstock GmbH)

[0019] P 2418 PCT - 4 - requires a lengthy thermal curing process. By using photobase generators for the production of photochromic products via UV light-induced curing, a synergistic effect can be achieved, as the prolonged thermal stress during conventional thermally induced polymerization can be avoided. Thus, a photochromic plastic body, in particular a plastic lens, preferably a plastic spectacle lens, with superior photochromic properties can be obtained.

[0020] The polymerizable mixture contains at least one photochromic dye. Such a mixture then exhibits photochromic behavior, which in particular means that the at least one photochromic dye contained in the mixture reacts to UV light.

[0021] Depending on the intensity of the incident UV light, the photochromic dye, if present, darkens or lightens through a reversible change in its molecular structure, also known as isomerization. A photochromic dye thus changes its absorption behavior in response to UV light irradiation. When the UV light irradiation ceases, the photochromic dye reverts to its original molecular structure and therefore its original absorption behavior. A photochromic dye thus enables reversible switching between dark and light tints in the final plastic component, such as in eyeglass lenses.

[0022] Particularly suitable as photochromic dyes are naphthopyrans, especially naphthopyrans, spirooxazines, and / or spiropyrans particularly suited to the selected poly(thio)urethane, which exhibit both rapid darkening behavior, even when embedded in poly(thio)urethane polymers, and high durability. In particular, the polymerizable mixture may contain not only one photochromic dye from the aforementioned compound groups, but also two or more, and the selected photochromic dyes may also differ. 120816P1423PC Rodenstock GmbH

[0023] P 2418 PCT - 5 -

[0024] Using such a mixture, supplemented by photochromic dyes, a photochromic layer can be produced on a substrate or a photochromic plastic body, which can preferably be used as a self-tinting spectacle lens and offers a high level of wearing comfort, as the spectacle lens dynamically adapts to the constantly changing light conditions of everyday life.

[0025] The at least one photochromic dye has at least one photochromic center, preferably selected from one of the aforementioned classes of compounds: naphthopyrans, spirooxazines, or spiropyrans, and at least one, preferably exactly one, polymer chain attached to this center. This polymer chain consists essentially of a polypropylene glycol monoalkyl ether to whose OH terminus the photochromic center is attached. The type of attachment, as well as the exact position on the photochromic center, are not relevant to the present invention, and the attachment can be effected, for example, via various types of bonds, such as ester or ether bonds. According to the invention, the polymer chain has at least 4, preferably at least 8, (PPG) repeat units. Preferably, the polymer chain has at least 4, preferably at least 8, up to a maximum of 45 repeat units.Particularly preferably, the at least one polymer chain has between 4 and 18 repeat units, in particular 8 and 18 repeat units or between 18 and 41 repeat units.

[0026] In the case of photochromic dyes without a polymer chain or with a polymer chain that is too short (3 or fewer repeating units), there is no or insufficient interaction between the surface additives (described in more detail below) and the photochromic dyes. This results, in particular, in unsatisfactory properties being achieved or present in the products after the photochromic dyes and surface additives are incorporated into a polymerizable (casting resin) mixture, especially a poly(thio)urethane mixture, and after their polymerization. This applies to both the photochromic darkening depth and lightening rate, as well as the product clarity. 120816P1423PC Rodenstock GmbH

[0027] P 2418 PCT - 6 - also referred to as visual clarity. The reason for this is that the cross-linking of the polymerizable mixture during curing negatively affects the isomerization behavior of the photochromic dyes or restricts it to such an extent that a photochromic reaction can only take place severely impaired or not at all, since the photochromic dye does not find (sufficient) space for its structural changes in the tightly cross-linked poly(thio-)urethane matrix.

[0028] The at least one surface additive is preferably an alkyl polyglycol ether, more preferably a polyglycol ether consisting of polyethylene glycol units (PEG) and polypropylene glycol units (PPG), and particularly preferably the surface additive is a block copolymer.

[0029] Block copolymers are polymers composed of two or more different monomer units. Generally, such block copolymers exhibit alternating, repeating units or blocks of ethylene oxide (EO) and propylene oxide (PO). The EO units are hydrophilic (water-soluble), whereas the PO units are lipophilic (water-insoluble), resulting in amphiphilic properties.

[0030] Even more preferably, the surface additive is a poloxamer, a selected form of a block copolymer comprising a central PPG block and, on either side of the central PPG block, an adjacent PEG block. The central PPG block can have a number of repeating PPG units, and the adjacent PEG blocks can themselves also have a number, in particular a number different from the number of PPG units, of repeating PEG units. These repeating units can also be represented as X / Y / X, with X as a placeholder for PEG and Y as a placeholder for PPG, where a ratio of PEG:PPG units can be specified as X:Y. Suitable poloxamers are commercially marketed under the brand name Pluronics®.Poloxamers are particularly suitable in combination with the photochromic dyes described above, since there is an advantageous interaction between the PPG repeat units of the central PPG block of the poloxamer and the 120816P1423PC Rodenstock GmbH.

[0031] P 2418 PCT - 7 -

[0032] PPG repeat units of at least one polymer chain of the photochromic dye take place, which overcomes the aforementioned disadvantages when incorporating photochromic dyes into a polymerizable casting resin mixture, especially into a poly(thio-)urethane mixture, i.e., through this interaction, after polymerization, a very good photochromic darkening depth and lightening speed, but also very good visual clarity, is achieved.

[0033] Preferably, the at least one surface additive is a poloxamer with a central PPG block comprising 10 to 45 (PPG) repeating units; more preferably, the surface additive is a poloxamer comprising 10 to 45 PPG units and a PEG : PPG unit ratio between 3:1 and 1:16. Further preferably, a poloxamer comprising between 13 and 21, particularly preferably about 16, PPG units, and a PEG : PPG unit ratio between 1:1 and 1:8, is also preferred. Equally preferred is a poloxamer comprising 22 to 42, particularly preferably about 31, PPG units, and a PEG : PPG unit ratio between 3:1 and 1:16.

[0034] The molar concentration of a photochromic dye in a polymerizable mixture is essentially determined by the desired photochromic properties. When forming a photochromic layer, coating, or sprue with the polymerizable mixture described above, a person skilled in the art can select a suitable dye concentration depending on the desired thickness of the photochromic layer and the target depth of darkening. With this predetermined dye concentration, adjustments to the parameters "polymer chain length of the dye," "surface additive concentration," "surface additive chain length," and "PEG / PPG ratio in the surface additive" are necessary to achieve the optimal photochromic properties of the dye.

[0035] The inventors of the present application have recognized that for 120816P1423PC Rodenstock GmbH

[0036] P 2418 PCT - 8 -

[0037] In the composition of such a polymerizable mixture for obtaining a photochromic layer, the molar ratio of photochromic dye to surface additive is crucial to prevent a loss of darkening depth. On the other hand, the ratio of PEG to PPG units of the surface additive is also critical, as a high PEG content of the additive is essential to prevent haze at higher additive concentrations, which would negatively affect the product's ocular clarity. Furthermore, the inventors recognized that the number of repeat units in the central PPG block of the additive is also an important factor, as a sufficiently large number of PPG repeat units is required to avoid a loss of darkening depth and lightening rate.Above the specified upper limits for the proportion of the surface additive, the inventors have recognized that problems can arise due to a softening of the polymer matrix, resulting in a reduction in the durability of the plastic body and a decrease in mechanical stability, which is particularly evident in reduced scratch resistance.

[0038] The composition of the polymerizable mixture also depends on a number of other factors familiar to those skilled in the art. For example, the proportion of photochromic dye in the polymerizable mixture depends on the desired thickness of the layer, particularly the photochromic layer, with this relationship being inversely proportional; that is, a thinner photochromic layer requires a higher proportion of photochromic dye in the polymerizable mixture than a thicker layer. Furthermore, the desired depth of darkening depends on the dye concentration and, of course, on the dye itself.

[0039] For a polymer chain length of 4 to 18 repeat units, preferably 8 to 18 repeat units on the photochromic dye, the molar ratio between photochromic dye and surface additive must be at least 1:5, preferably at least 1:12, to prevent a loss of darkening depth. 120816P1423PC Rodenstock GmbH

[0040] P 2418 PCT - 9 -

[0041] For a polymer chain length of 18 to 45 repeat units on the photochromic dye, preferably 18 to 41 repeat units, the molar ratio between photochromic dye : surface additive must be at least 1 :10 to prevent clouding caused by excessively high or low surface additive levels, which would negatively affect the product's clarity.

[0042] Preferably, the polymerizable mixture comprises at least one photochromic dye, comprising at least one polymer chain, preferably exactly one polymer chain, comprising 8 to 18 repeat units, and

[0043] - at least one poloxamer with 13 to 21 PPG units with a PEG : PPG unit ratio of 1 :1 to 1 :8, or

[0044] - at least one poloxamer with 22 to 40 PPG units and a PEG : PPG unit ratio of 3:1 to 1:16, and wherein the molar ratio of photochromic dye : surface additive is in the range of 1:1 to 1:90, preferably between 1:3 and 1:70, more preferably between 1:3 and 1:35.

[0045] Advantageously, this choice of molar ratio between the photochromic dye, comprising a medium-length polymer chain, and the surface additive prevents a loss of darkening depth. In other words, by fulfilling the aforementioned criteria, an excellent darkening performance is ensured for a photochromic dye comprising at least one polymer chain, preferably exactly one polymer chain, with 8 to 18 repeat units. Simultaneously, the selected ratio of PEG : PPG units ensures that a sufficiently large number of PEG units are present to prevent haze. Furthermore, the number of PPG units in the central PPG block of the additive ensures that a loss of darkening depth and lightening speed is avoided. 120816P1423PC Rodenstock GmbH

[0046] P 2418 PCT - 10 -

[0047] Preferably, the polymerizable mixture comprises at least one photochromic dye comprising at least one polymer chain, preferably exactly one polymer chain, comprising 19 to 45 repeating units, and at least one poloxamer comprising 22 to 42 PPG units with a PEG : PPG unit ratio of 3:1 to 1:2.5; and wherein the molar ratio of photochromic dye : surface additive is in the range of 1:1 to 1:90, preferably between 1:3 and 1:70, more preferably between 1:3 and 1:35.

[0048] Advantageously, this choice of molar ratio between the photochromic dye, which has a polymer chain of greater length, and the surface additive prevents a loss of darkening depth; i.e., by fulfilling the aforementioned criteria, excellent darkening behavior is ensured for a photochromic dye having at least one polymer chain, preferably exactly one polymer chain, with 19 to 45 repeat units, while at the same time, the selected ratio of PEG : PPG units ensures that a sufficiently large number of PEG units are present to prevent turbidity, and the number of PPG units in the central PPG block of the additive further ensures that a loss of darkening depth and lightening rate is avoided.

[0049] Preferably, a polymerizable mixture for obtaining a photochromic layer, preferably formed by a casting process for producing a particularly photochromic plastic body or semi-finished product, having a preferred layer thickness of 0.1 to 1.0 mm, more preferably having a layer thickness of about 400 pm, comprises a proportion of photochromic dye in the mixture of 0.1 to 2.0, preferably a (weight) proportion of 0.2 to 1.0, and particularly preferably a proportion of 0.3 to 0.7, wherein the molar ratio of dye to surface additive is from 1:3 to 1:90. Advantageously, this choice of molar ratio between photochromic dye and surface additive prevents a loss of darkening depth, i.e., by a molar ratio, fulfills the aforementioned requirements. 120816P1423PC Rodenstock GmbH

[0050] P 2418 PCT - 11

[0051] The criteria ensure excellent darkening performance, while at the same time the selected ratio of PEG : PPG units ensures that a sufficiently large number of PEG units are present to prevent haze, and the number of PPG units in the central PPG block of the additive further ensures that a loss of darkening depth and brightening speed is avoided.

[0052] Preferably, a polymerizable mixture for obtaining a photochromic layer, preferably formed by a rotational coating process for producing a particularly photochromic plastic body or semi-finished product, having a preferred layer thickness between 0.001 and 0.1 mm, more preferably having a layer thickness of about 45 pm, comprises a proportion of photochromic dye in the mixture of 1.0 to 10.0, preferably a proportion of 2.0 to 8.0, particularly preferably a proportion of 3.5 to 5.5, wherein the molar ratio of dye to surface additive is between 1:1 and 1:70.

[0053] Above the specified upper limits for surface additive content, problems with the plasticization of the polymer matrix can occur, resulting in a reduction in durability and mechanical stability, such as the scratch resistance of the plastic body.

[0054] It goes without saying that for the (photo)polymerizable mixture proposed according to this aspect, all further developments and sub-aspects explained in the following aspects of the present application, in particular in the explanations relating to the following process, shall also apply, and vice versa.

[0055] Another aspect concerns a process for manufacturing a photochromic plastic body comprising the following steps:

[0056] S100: Providing a substrate;

[0057] S102: Providing a polymerizable mixture of isocyanates and

[0058] Isocyanate-reactive components, wherein the mixture contains at least one 120816P1423PC Rodenstock GmbH

[0059] P 2418 PCT - 12 -

[0060] surface additive, and comprising at least one photochromic dye, at least one photochromic center to which at least one polymer chain is bonded, preferably exactly one polymer chain, comprising at least 4, preferably at least 8, repeating units, and comprising at least one surface additive, and comprising at least two of the following components:

[0061] A poly(thio-)urethane prepolymer prepared from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is such that there is an excess of isocyanate-reactive groups compared to isocyanate groups;

[0062] A poly(thio-)urethane prepolymer prepared from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is such that there is an excess of isocyanate groups compared to isocyanate-reactive groups; a thiol component and an isocyanate component; wherein the ratio of isocyanate groups to thiol groups / isocyanate-reactive groups is 0.95:1 to 1:0.95;

[0063] S104: Mixing this polymerizable mixture with at least one further additive, wherein this additive is or comprises a photobase generator to obtain a photopolymerizable mixture;

[0064] S106: Applying the photopolymerizable mixture to the substrate;

[0065] S108: Curing of the photopolymerizable mixture by exposure to light, especially UV light, to form a plastic body.

[0066] Preferably, the method comprises steps S100, S102, S104, S106, S108 in this order.

[0067] In one, and especially first, process step S100, a substrate is provided, which can be any base body or carrier material onto which a polymerizable composition is cast, coated, or applied using this process, which, after appropriate curing, results in a sprue, a layer, a coating, an additional component, or an additional 120816P1423PC Rodenstock GmbH

[0068] P 2418 PCT - 13 -

[0069] Position on the substrate leads to this.

[0070] To be suitable, particularly for later use as a lens, the base body should possess sufficient optical quality with regard to its optical imaging properties. Those skilled in the art understand optical imaging properties to encompass a multitude of determinable, characteristic quantities that can characterize a given object, such as a base body, with respect to its optical imaging properties. These include properties such as spectral transmission, color rendering, and the Abbe number. This is particularly relevant in the use of plastics as materials for the manufacture of lenses, especially ophthalmic lenses.For spectacle lenses, materials such as poly(thio-)urethane, polymethyl methacrylate, polycarbonate, polyacrylate, polydiethylene glycol bisallyl carbonate or combinations thereof have proven to be preferred in recent years, although in principle other transparent plastic materials can also be used.

[0071] In a further, specifically second, process step S102, a polymerizable mixture of isocyanates and isocyanate-reactive components is provided. To obtain a polymerizable mixture from these components, the respective components must possess two or more of their eponymous functional groups. In other words, the isocyanate component comprises divalent or multivalent isocyanates, preferably diisocyanates, and the isocyanate-reactive component comprises at least thiols or alcohols with two or more functional groups, i.e., SH or OH groups. The ratio of isocyanate groups to thiol groups / isocyanate-reactive groups is from 0.95:1 to 1:0.95. The provided polymerizable mixture comprises at least two of the following components:

[0072] The polymerizable mixture may contain a poly(thio-)urethane prepolymer produced from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is or was chosen such that there is or was an excess of isocyanate-reactive groups relative to isocyanate groups. The prepolymer provided is 120816P1423PC Rodenstock GmbH

[0073] P 2418 PCT - 14 - is a composition which has undergone a first pre-polymerization, characterized in particular by the addition of isocyanate-reactive groups in a defined excess. The prepolymer thus still possesses many reactive groups which can be used for polymerization in a further process step. Such a prepolymer is generally formed by the supply of thermal energy, i.e., the pre-polymerization is thermally induced. Preferably, the polymerizable mixture containing isocyanate components and isocyanate-reactive components is heated in a suitable container or reactor under constant stirring. In a further development, the reaction is accelerated by the addition of a metal catalyst.Preferably, the polymerizable mixture comprises a poly(thio-)urethane prepolymer prepared from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is or was selected such that the excess of isocyanate-reactive groups is present in relation to the isocyanate groups, and the proportion of isocyanate groups present in the polymerizable mixture corresponds to at most approximately 50%, preferably at most approximately 30%, of the isocyanate-reactive groups present in the mixture. Advantageously, due to the excess of isocyanate-reactive components used, the prepolymer still contains many isocyanate-reactive groups, which can be used for polymerization in a further process step.

[0074] Alternatively or additionally, the polymerizable mixture can comprise a poly(thio-)urethane prepolymer produced from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is or was chosen such that there is or was an excess of isocyanate groups relative to isocyanate-reactive groups. The provided prepolymer is a composition that has undergone a first pre-polymerization, characterized in particular by the addition of isocyanate groups in a defined excess. The prepolymer thus still possesses many reactive groups that can be used for polymerization in a further process step. Such a prepolymer is generally formed by the addition of thermal energy, i.e., the pre-polymerization was carried out thermally. 120816P1423PC Rodenstock GmbH

[0075] P 2418 PCT - 15 - induced, preferably the polymerizable mixture comprising isocyanate components and isocyanate-reactive components is heated under constant stirring in a container or reactor suitable for this purpose; in a further development, acceleration takes place by the addition of a metal catalyst. Preferably, the polymerizable mixture comprises a poly(thio-)urethane prepolymer prepared from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is or was chosen such that the excess of isocyanate groups is or was present in relation to isocyanate-reactive groups, and the proportion of isocyanate-reactive groups present in the polymerizable mixture corresponds to at most about 50%, preferably at most about 30%, of the isocyanate groups present in the mixture.Advantageously, due to the excess of isocyanate components used, the prepolymer still has many isocyanate groups which can be used for polymerization in a further process step.

[0076] In particular, the introduction of so-called prepolymers into a polymerizable mixture, preferably into a polymerizable mixture for obtaining a poly(thio)urethane, also referred to as a poly(thio)urethane casting resin mixture, can, in combination with a photobase generator in a photopolymerizable mixture, increase the degree of curing of the light-induced polymerization and advantageously improve the optical quality of the resulting plastic body, especially by reducing the tendency to form streaks. The viscosity of the polymerizable mixture can also be specifically controlled or influenced by the proportion of prepolymers. Advantageously, the viscosity of a polymerizable mixture can be optimized by the targeted use or addition of such prepolymers, particularly with regard to the suitability of such a polymerizable mixture for application by means of a spin coating or similar process.

[0077] The viscosity of prepolymers used in centrifugal or rotary coating processes can be specifically influenced, particularly increased, to achieve improved application through higher viscosity. Such prepolymers can be produced by thermally induced prepolymerization with a large excess of a reactive component (diisocyanates or polythiols / polyols). 120816P1423PC Rodenstock GmbH

[0078] P 2418 PCT - 16 - are generated.

[0079] In other words, the provided polymerizable mixture can contain at least one poly(thio-)urethane prepolymer, wherein this prepolymer is optionally a prepolymer containing an excess of isocyanate or a prepolymer containing an excess of isocyanate-reactive groups, or in a further development thereof, the polymerizable mixture contains both types of prepolymers.

[0080] Alternatively (or additionally), the polymerizable mixture comprises at least one isocyanate-reactive component or thiol component; preferably, the polymerizable mixture comprises two or more thiol components. Preferably, such a thiol component is selected from one of the compounds pentaerythritol tetrakis-(3-mercaptopropionate), 4-(mercaptomethyl)-1,8-dimercapto-3,6-dithiaoctane, or 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane. In particular, the polymerizable mixture may comprise not only one thiol component from the aforementioned compounds, but also two or more, wherein the selected thiol components may also differ.Particularly in conjunction with a polymerizable mixture containing a poly(thio-)urethane prepolymer exhibiting an excess of isocyanate groups relative to isocyanate-reactive groups, complete polymerization can be ensured by adding thiol components. Advantageously, the polymerizable mixture contains a defined addition of thiol components, tailored to the existing excess of isocyanate groups, to guarantee complete polymerization in a subsequent process step.

[0081] Furthermore, the polymerizable mixture comprises at least one isocyanate component, preferably exactly one isocyanate component. Alternatively, the polymerizable mixture comprises two or more isocyanate components. Preferably, such an isocyanate component is selected from one of the compounds isophorone diisocyanate, 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]heptane, 4,4'-diphenylmethane diisocyanate, 4,4'-dicyclohexanemethane diisocyanate, toluene diisocyanate, xylene diisocyanate, or 120816P1423PC Rodenstock GmbH

[0082] P 2418 PCT - 17 -

[0083] Hexamethylene diisocyanate, 1,3-bis(isocyanatomethyl)benzene, or 1,6-diisocyanatohexane. In particular, the polymerizable mixture can contain not only one isocyanate component from the aforementioned compounds, but also two or more, and the selected isocyanate components may also differ. Especially in combination with a polymerizable mixture containing a poly(thio)urethane prepolymer that has an excess of isocyanate-reactive groups relative to isocyanate groups, complete polymerization can be ensured by additional isocyanate components. Advantageously, the polymerizable mixture has a defined addition of isocyanate components, tailored to the existing excess of isocyanate-reactive groups, in order to ensure complete polymerization in a further process step.

[0084] In the polymerizable mixture, the ratio of isocyanate groups to thiol groups or isocyanate-reactive groups is from 0.95:1 to 1:0.95.

[0085] In particular, with regard to the two previously described configurations of poly(thio-)urethane prepolymers, it should be noted that, since both the viscosity of a prepolymer and the reaction rate of polyaddition reactions are highly dependent on the molecular size, the conditions of the prepolymerization process must be carefully chosen to achieve an appropriate curing rate in the case of late curing, especially curing by exposure to (UV) light.

[0086] In further development, the polymerizable mixture can contain additional components which, especially after (complete) polymerization, impart one or more or a multitude of additional and / or alternative properties to the mixture. This allows the provided polymerizable mixture to be further developed for a wide variety of possible applications and makes it particularly versatile.

[0087] In a further, in particular third, process step S104, the polymerizable mixture is mixed with at least one further 120816P1423PC Rodenstock GmbH

[0088] P 2418 PCT - 18 -

[0089] Additive, wherein this additive is a photobase generator or has a photobase generator, for obtaining a photopolymerizable mixture, i.e. a mixture which can be cured by exposure to light.

[0090] A photobase generator is a photoactive chemical compound that, upon irradiation with light, particularly UV light, generates or provides organic bases, such as amines. These amine bases, provided by photobase generators, can serve as catalysts in the curing process of poly(thio)urethanes and enable the curing of polymerizable mixtures, especially curing by UV light. In other words, irradiation of a photobase generator with (UV) light induces the release of a catalytically active species, particularly catalytically active amines, which, in a polymerization process, facilitates the reaction of monomeric components, such as isocyanates and isocyanate-reactive components, especially thiols, but also of prepolymers with corresponding reactive groups, particularly NCO, SH, and / or OH groups, without the need for additional thermal energy.Advantageously, by mixing or adding a photobase generator as an additive to a provided polymerizable mixture, a (UV-)photopolymerizable mixture can be obtained, whereby subsequent polymerization, i.e. the curing of the components of the polymerizable composition, advantageously, and in particular preferably, already takes place at room temperature, especially without additional thermal energy input.The choice of a suitable compound as a photobase generator depends on many factors, for example on the chemical composition of the monomers in the polymerizable mixture and / or on (quality) requirements for the polymerized product, whereby the preservation of certain optical properties in connection with its use as a plastic body, in particular as a plastic lens, preferably as an ophthalmic plastic lens, especially preferably as a plastic spectacle lens, plays a major role.

[0091] In principle, various classes of substances are suitable as photobase generators, 120816P1423PC Rodenstock GmbH

[0092] P 2418 PCT - 19 - Special carbamates can be used, among other things. The carbamate group represents the connection between a light-absorbing chromophore and the amine base to be released. Non-limiting examples include 2-nitrobenzyl N,N-dimethylcarbamate, 3,5-dimethoxybenzyl N,N-dimethylcarbamate, and 1-pyrenylmethyl-1-piperidinecarboxylate. Another class of substances that can be used for photobase generators are special ammonium salts, particularly ammonium salts in which the ammonium cation is covalently bonded to a light-absorbing chromophore. Non-limiting examples include 1-(2-phenyl-2-oxoethyl)-1,1,1-trimethylammonium thiocyanate and 1-(4-benzoylphenyl)-methyl-quinuclidonium thiocyanate. Alternatively, the light-absorbing chromophore can also be contained in the counterion (anion) of the ammonium salts. Various carboxylate salts are examples of this.Non-limiting examples include triethylammonium 2-(2-9H-Xathonyl)ethylcarboxylate and N,N-diisopropylethylammonium 2-(benzoylphenyl)2-methylethylcarboxylate. Ammonium salts of tetraarylborates also fall into this category. Due to their good solubility in the aforementioned components of the mixture, ammonium salts of tetraarylborates are particularly suitable as photobase generators, especially those salts with ammonium ions containing a tetrasubstituted nitrogen atom, three of which are essentially alkyl groups and the remaining atom is essentially hydrogen. Non-limiting examples include triethylammonium tetraphenylborate, N,N-diisopropylethylammonium tetraphenylborate, and quinuclidonium tetra(4-chlorophenyl)borate.Such a photobase generator can be added as a pure substance, or dissolved in one of the above-mentioned thiol components, or dissolved in one of the above-mentioned isocyanate components, or dissolved in a common organic solvent.

[0093] Preferably, the photobase generator is selected from the group of

[0094] Ammonium salts of tetraarylborates, preferably an ammonium tetraarylborate salt of a tertiary amine according to formula (I): 120816P1423PC Rodenstock GmbH

[0095] P 2418 PCT - 20 - wherein the residues Ri, R2 and R3 each independently represent unsubstituted or monosubstituted (Ci-C2o) alkyl residues, wherein the substituent can be selected from fluorine, chlorine, bromine, a phenyl residue, a hydroxy residue, a (C1-C4) alkoxy residue or a polyoxyalkene residue, wherein the alkylene unit has 2 to 4 carbon atoms and the repeating unit n is between 1 and 20; wherein the residue R4 is essentially hydrogen; wherein the residues Rs, Re, Ry and Rs each independently represent phenyl residues having between zero and four substituents, or naphthyl residues having between zero and two substituents, wherein the substituents may be selected from fluorine, chlorine, bromine, a phenyl residue, a (Ci-C4) alkyl residue, a (Ci-C4) alkoxy residue or a trifluoromethyl residue.

[0096] Preferably, the residues Ri, R2, and R3 differ from one another, i.e., they are distinct. Alternatively, they can preferably, and in particular all of them, be identical. In a further development of this, two or three residues can preferably form one or more cycles together.

[0097] Preferably, the residues Rs, Re, R7 and Rs differ from each other, i.e., they are distinct. Alternatively, they can preferably, and in particular all of them, be identical to each other.

[0098] Preferably, the proportion of the photobase generator in the mixture is less than or equal to 10 parts, more preferably less than or equal to 5 parts, more preferably less than or equal to 1 part, most preferably less than or equal to 0.5 parts, and in particular exactly 0.25 parts. 120816P1423PC Rodenstock GmbH

[0099] P 2418 PCT - 21

[0100] In a further, particularly fourth, process step S106, the photopolymerizable mixture is applied to the substrate. This step is not further restricted, and a variety of possible methods can be selected for applying such a mixture to a substrate. The photopolymerizable mixture is preferably applied by spin coating or by casting. In spin coating, also known as centrifugal coating, the mixture is applied to the substrate, and the substrate is then rotated in such a way that the mixture spreads uniformly to obtain a uniform layer on the substrate. Alternatively, the polymerizable mixture can also be applied while the substrate is already rotating.Typically, such application by spin-coating takes place in a dedicated device, also known as a spin coater, which is generally suitable for layer thicknesses of up to approximately 100 pm, preferably up to approximately 50 pm. In a casting process, a layer of the photopolymerizable mixture is cast onto the substrate. This is typically done by forming a cavity by arranging the substrate against a mold, also called a casting mold, and then filling the cavity with the photopolymerizable mixture. Devices familiar to those skilled in the art from the casting of plastic lenses are typically suitable for this purpose, with one of the two molds being replaced by the substrate.In general, layer thicknesses of up to approximately 1 mm can be achieved with such a casting process.

[0101] In a further, in particular fifth, process step S108, the photopolymerizable mixture or the layer formed by the photopolymerizable mixture is cured or polymerized. Curing can generally be achieved either by light, in particular UV light, or by a combination of irradiation with light, in particular UV light, followed by thermal curing. This is particularly relevant for a mixture comprising a photobase generator as a preferred additive (120816P1423PC Rodenstock GmbH).

[0102] P 2418 PCT - 22 - curing occurs through irradiation with light, particularly UV light. The photobase generator, provided as an additive, absorbs the energy of the incident (UV) light and releases an amine compound that catalyzes the polyaddition of the isocyanates with the isocyanate-reactive components. In other words, polymerization and curing take place at room temperature and, in particular, without the addition of thermal energy. This method allows for particularly cost-effective curing, as the energy-intensive and time-consuming thermal curing process can be avoided. Curing the mixture applied to the substrate results in the formation of a semi-finished product.

[0103] Preferably, the polymerizable mixture provided in step S102 comprises one or more of the following components

[0104] - at least one dye that is different from the photochromic dye

[0105] - at least one UV absorber

[0106] - at least one photosensitizer

[0107] - at least one metal catalyst

[0108] - at least one surfactant.

[0109] In other words, the polymerizable mixture comprises at least one photochromic dye and at least one surface additive and at least one polymerizable mixture as defined above, and optionally at least one (further) component selected from the group consisting of:

[0110] - Dyes that are different from photochromic dyes;

[0111] - UV absorber;

[0112] - Photosensitizer;

[0113] - Metal catalyst.

[0114] - surfactant.

[0115] Possible additional components are explained in more detail in the following paragraphs, with particular emphasis on the fact that the polymerizable mixture optionally contains none of these components, in a modification thereof one, in a further development thereof two, in a further development 120816P1423PC Rodenstock GmbH

[0116] P 2418 PCT - 23 - several of these, and in further training may exhibit all components.

[0117] Alternatively (or additionally), the polymerizable mixture can contain a dye that differs from the photochromic dye as defined above. The dye can, for example, impart a characteristic color or special absorption properties to the mixture, such as a filtering effect. Such a modified mixture then exhibits a new or additional property: a pre-coloration or a different transmission characteristic compared to a mixture without dye. This results in a colored mixture, which can advantageously be used to produce a colored layer or a colored plastic body. Preferably, these are azo dyes, cyanine dyes, anthraquinone dyes, or the like, such as those commonly used in the conventional coloring of plastic bodies, especially plastic spectacle lenses.In particular, the polymerizable mixture may contain not only one dye from the aforementioned groups of compounds, but also two or more, and the selected dyes may also differ. A person skilled in the art routinely selects a suitable dye or a mixture of suitable dyes.

[0118] Alternatively (or additionally), the polymerizable mixture can contain at least one UV absorber. In other words, such an absorber can bring about a desired absorption behavior, such as, in particular, increased absorption in the UV range to provide UV protection. A mixture modified in this way then exhibits, as a new or additional property, increased, improved, or partial protection against UV light, which is understood to mean, in particular, that the modified mixture has at least a partial filtering or blocking effect against UV light. Preferably, such a UV absorber is selected from one of the compound groups benzophenones, benzotriazoles, or oxanilides. In particular, the polymerizable mixture can contain not only one UV absorber from the aforementioned compound groups, but also two or more.

[0119] P 2418 PCT - 24 - several, whereby the selected UV absorbers may also differ. Depending on the type and properties of the UV absorber used, it may also be necessary to add dyes to mask any existing pre-coloration of the mixture. For example, if additional components are added to provide enhanced protection against the transmission of radiation from the ultraviolet and blue spectral ranges, the resulting targeted removal of radiation, particularly from the visible spectrum, can lead to a non-neutral color rendering of transmitted light, for example, due to the partial removal of blue light. In such a case, this is referred to as the presence of an inherent coloration, which in the above example would cause a yellow tint. This can, in turn, be compensated for by adding a blue dye to achieve a neutral color.Advantageously, a UV absorber is added in combination with a suitable dye to compensate for a non-neutral color appearance. Therefore, in such a case, at least two additives are included in the mixture. Using such a mixture, supplemented by a UV absorber and, if necessary, additional (compensating) dyes, a plastic body can be produced that offers UV protection and, when preferably used as a spectacle lens, effectively protects the wearer's eyes from harmful UV light while simultaneously exhibiting a neutral appearance and color impression, i.e., in particular, no inherent coloration.

[0120] Alternatively (or additionally), the polymerizable mixture can contain at least one photosensitizer. A photosensitizer is a compound that acts as a type of photochemical catalyst, absorbing incident light of a defined wavelength and transferring at least some of the energy absorbed to a second compound. This second compound can then initiate or participate in a reaction using the transferred energy. Without such a photosensitizer, the second compound would not be able to initiate or participate in a reaction, as its absorption band does not overlap with the wavelength of the incident light; that is, the second compound cannot absorb light of the incident wavelength. Preferably, such a photosensitizer is 120816P1423PC Rodenstock GmbH

[0121] P 2418 PCT - 25 -

[0122] Photosensitizer selected from one of the compound groups thioxanthones, anthracenes, or coumarins. In particular, the polymerizable mixture may contain not only one photosensitizer from the aforementioned compound groups, but also two or more, and the selected photosensitizers may also differ.

[0123] Alternatively (or additionally), the polymerizable mixture can comprise at least one metal catalyst. Such a metal catalyst is particularly advantageous in thermally induced curing processes, as it catalyzes the thermal curing process, which means that the thermal energy required for curing is reduced. Preferably, such a metal catalyst is selected from the group of organotin compounds; dimethyltin chloride is a particularly preferred metal catalyst. In particular, the polymerizable mixture can comprise not only one metal catalyst from the aforementioned group of compounds, but also two or more, and the selected metal catalysts can also differ.

[0124] Alternatively (or additionally), the polymerizable mixture may contain at least one surfactant. These are understood to be surface-active or surface-sensitive substances that can modify the wetting, adhesion, flow, hardness, or fracture properties of the polymerizable mixture, both in its uncured state and in its cured state. Preferably, such a surfactant is selected from the groups of alkyl phosphates or polydimethylsiloxanes. In particular, the polymerizable mixture may contain not only one surfactant from the aforementioned groups, but also two or more, and the selected substances may also differ.Examples of surfactants are inner releasers, which are preferably used in so-called casting processes when forming an (additional) layer by casting and curing a polymerizable mixture, or leveling additives, which are preferably used in rotational coating (spin coating) processes, 120816P1423PC Rodenstock GmbH.

[0125] P 2418 PCT - 26 -

[0126] They can be used.

[0127] Preferably, the addition of isocyanates or isocyanate components and / or thiols or isocyanate-reactive components is carried out in combination with at least one further additive, such as a dye, a UV absorber, a photosensitizer, a metal catalyst and / or a surface activator, since this advantageously allows pre-dissolution of the at least one further additive in the isocyanates or thiols.

[0128] Providing a polymerizable mixture includes both providing an existing mixture and mixing substances or compounds, in particular isocyanates and isocyanate-reactive components and optionally a metal catalyst, with subsequent thermally induced pre-polymerization to obtain such a polymerizable mixture or a corresponding prepolymer, which is provided for the process.

[0129] Preferably, the polymerizable mixture comprises at least one of the aforementioned additives, such as a dye, a UV absorber, a photosensitizer, a metal catalyst, and / or a surfactant; more preferably, it comprises a plurality of these additives to impart a new property or additional properties to the mixture. For example, the addition of UV absorbers provides the plastic body with protection against harmful UV radiation. Any additives can be selected from the preceding list, particularly combinations of different additives, to obtain the desired product properties.

[0130] In a further, optional process step S110, thermal post-treatment, also known as tempering, can take place, whereby this process step follows curing with light, in particular with UV light. During such a tempering step, the formed semi-finished product or plastic body is heated by means of thermal energy input, thereby achieving its full hardness, reducing internal stresses, and resulting in a semi-finished product or plastic body. 120816P1423PC Rodenstock GmbH

[0131] P 2418 PCT - 27 - is used. Advantageously, this results in a semi-finished product or...

[0132] Plastic body obtained, which has a high mechanical strength and resistance.

[0133] In a further, particularly optional, process step S112, at least one coating is formed on the plastic body. This includes all finishing processes, such as lacquers, especially buffer lacquers to increase or improve the impact resistance of the plastic body, hard lacquers to increase or improve the scratch resistance of the plastic body, and / or coatings, especially adhesive layers to increase or improve the adhesion properties of the plastic body, (multilayer) interferometric coating systems to form an anti-reflective or mirrored plastic body, and functional coatings to form a glass body exhibiting functional properties, such as hydrophobic and / or oleophobic properties.Preferably, such a plastic body is provided with one or more such coatings to obtain a combination of advantageous properties; for example, such a plastic body can be provided with a buffer varnish, a hard varnish, an adhesive layer, a multi-layer interferometric anti-reflective coating, and a functional coating to obtain a break- and scratch-resistant, anti-reflective, and hydrophobic plastic body.

[0134] In an advantageous embodiment, one or both of steps S110 and S112 are provided, preferably in the order indicated by the (ascending) numbering of the respective step with reference to each other and / or the aforementioned steps S100, S102, S104, S106, S108, S110, S112, without the invention being limited thereto.

[0135] The presented method is versatile and it goes without saying that process steps can be arranged in any order and, in particular, repeated to obtain or produce a plastic body with a combination of new or additional and especially advantageous properties. It is equally self-evident that the methods known to those skilled in the art, or belonging to the prior art, are already established. (120816P1423PC Rodenstock GmbH)

[0136] P 2418 PCT - 28 -

[0137] Process steps can be supplemented, such as evacuating the polymerizable mixture and / or using special devices for applying the polymerizable mixture or for demolding. This process can be used to produce plastic bodies, in particular plastic lenses, preferably ophthalmic plastic lenses, and most preferably plastic spectacle lenses, which, through a suitable selection of additives added to the polymerizable mixture, can exhibit a variety of advantageous or useful properties, especially excellent photochromic properties. The presented process can be used to produce a plastic body on its own, or a provided substrate can be modified with an additional layer, a sprue, or other component.a coating is applied, with both initial situations having in common that the produced plastic body has new or additional and in particular advantageous properties, wherein the additional properties are realized via additives such as dyes, UV absorbers, photosensitizers, metal catalysts and / or surface activators, which are contained or provided in the (photo-)polymerizable mixture.

[0138] One aspect concerns a plastic body, in particular a plastic lens, preferably a plastic spectacle lens or spectacles or contact lenses equipped with at least one such lens, produced according to the preceding process. The plastic body produced in this way is characterized in particular by the fact that, according to the preceding process, it was polymerized by (UV) light-induced curing of a photopolymerizable mixture, wherein a polymerizable mixture comprising at least one isocyanate, at least one surface additive, at least one photochromic dye, and an isocyanate-reactive component was first mixed with an ammonium salt of tetraarylborate as a preferred photobase generator to obtain a photopolymerizable mixture. It is understood that the application of such a lens is not limited to spectacle optics or...not limited to contact lenses, but also applies to other optical lenses in the fields of photography, projection, 120816P1423PC Rodenstock GmbH.

[0139] P 2418 PCT - 29 -

[0140] Microscopy, lighting, for example in mobile phones, headlights, optical measuring instruments, etc. can be used.

[0141] One aspect concerns a plastic body, in particular a plastic lens, preferably a plastic spectacle lens, provided with an additional layer or overlay according to the preceding method, wherein this additional layer is optionally produced or formed by a casting or spin coating process. This layer is characterized in particular by the fact that it was polymerized according to the preceding method by applying a photopolymerizable mixture and subsequent (UV) light-induced curing, wherein a polymerizable mixture comprising at least one isocyanate, at least one surface additive, at least one photochromic dye, and an isocyanate-reactive component was first mixed with an ammonium salt of tetraarylborate as a preferred photobase generator to obtain a photopolymerizable mixture.

[0142] One aspect concerns a semi-finished product manufactured according to a method according to the invention. This semi-finished product can be subjected to further processing steps, in particular to apply further coatings, such as at least one protective layer which, due to its hardness, protects against mechanical damage, and / or an anti-reflective coating which reduces the reflection of light at the interfaces of the semi-finished product, and / or a mirror coating which increases the reflection of light at the interfaces of the semi-finished product, and / or a hydrophobic and / or oleophobic layer which reduces the adhesion of hydrophilic and / or oleophilic substances. The semi-finished product can also be mechanically processed to achieve a predetermined shape.

[0143] One aspect concerns a plastic body, in particular a spectacle lens, which is manufactured from a semi-finished product according to the invention, preferably by carrying out one of the processing steps mentioned in the preceding paragraph. The mechanical processing of the spectacle lens as a preferred embodiment of 120816P1423PC Rodenstock GmbH

[0144] P 2418 PCT - 30 -

[0145] The plastic body can, in particular, be a molding process to enable the lens to be inserted into a predetermined spectacle frame. The insertion of one or two lenses into a frame leads to a further aspect of the invention, namely to spectacles using at least one plastic body or semi-finished product according to the invention.

[0146] It goes without saying that the plastic body could also be another optical lens, for example for cameras, sensors, smartphones, microscopes, or similar devices. Alternatively, the plastic body could also be at least part of a housing for a light source (e.g., an LED, a headlight), an (optical) sensor, or a protective housing with at least one transparent section. In particular, the plastic body, with its excellent photochromic properties, could be advantageously suited to protecting an (optical) sensor from excessive amounts of incident light, especially UV light.

[0147] Unless otherwise stated, the indication of proportions in the present application, in particular in connection with the designation of proportions of different components in a mixture or composition, refers to weight percent or weight percent proportions.

[0148] In this application, numerical values ​​for repeating units or (chain) lengths of polymer chains always refer to an average value, which generally corresponds to the mean of the Gaussian distribution of chain lengths determined by the manufacturing and / or polymerization process. This applies in particular to the polymer chain of the dye as well as to the polymer chain or repeating units of the surface additive.

[0149] The stated numerical values, which are indicated with "approximately", may preferably deviate by + / - 10% from the stated value, more preferably by + / - 5% from the stated value, more preferably by + / - 2% from the stated value, and in particular may be exactly the stated value.

[0150] The phrase "essentially" means that a substance or material or 120816P1423PC Rodenstock GmbH

[0151] P 2418 PCT - 31 a mixture or composition or compound consists mainly of the specified substance or material, i.e., “X consists substantially of Y” means that the proportion of Y in X is in particular greater than or equal to 50%, preferably greater than or equal to 75%, and most preferably greater than or equal to 90%, and also includes the case where X consists or is formed only of Y.

[0152] The following describes embodiments of the invention in more detail with reference to the figures. It is understood that the present invention is not limited to the embodiments shown in the figures, and that individual features of different embodiments can be combined to form further embodiments within the scope of the accompanying claims. Identical reference numerals indicate identical or recurring elements. The figures show:

[0153] Fig. 1 is a schematic drawing of an embodiment of the method according to one aspect of the invention;

[0154] Fig. 2 shows a section of an embodiment of a semi-finished product, manufactured according to a method according to one aspect of the invention, preferably as shown in Fig. 1;

[0155] Fig. 3 shows a schematic drawing of a further development of the process from Fig. 1, including additional, optional process steps;

[0156] Fig. 4 is a schematic drawing of an embodiment of a plastic body or semi-finished product, the further development of the plastic body or semi-finished product produced according to a method according to an aspect of the invention, preferably as shown in Fig. 3;

[0157] Fig. 5 shows a structural representation or formula of an embodiment of a photobase generator.

[0158] To ensure maximum clarity, the following paragraphs describe the process according to Figure 1 in conjunction with the object from Figure 2, taking particular account of the fact that an object according to Figure 2 is preferably manufactured, or can be manufactured, according to a process according to Figure 1. 120816P1423PC Rodenstock GmbH

[0159] P 2418 PCT - 32 -

[0160] Figure 1 shows a schematic drawing of an embodiment of the method for producing a plastic body or semi-finished product 1 according to one aspect of the invention, as shown in Figure 2, wherein this semi-finished product 1 has a substrate 2, wherein an additional layer or overlay or also a sprue 3 has been formed on the substrate 2.

[0161] In a first step S100, a substrate 2 is provided. Preferably, a plastic spectacle lens, particularly preferably made of poly(thio-)urethane with a refractive index of about 1.6 at a wavelength of about 550 nm, is provided as substrate 2. In a next step S102, a polymerizable mixture is provided, wherein the provision includes both the preparation of such a mixture and the use of a previously prepared such mixture. Preferably, in this step, a polymerizable mixture according to one aspect of the invention is provided, which comprises a prepolymer as a first component. A poly(thio-)urethane prepolymer with an excess of thiol components (and thus isocyanate-reactive components) is used as the preferred prepolymer.Such a prepolymer can be obtained by mixing the following components in the specified proportions under heating to about 80 °C with constant stirring, followed by prepolymerization for about 7 hours: 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]-heptane as a preferred compound for one or the isocyanate component, pentaerythritol-tetrakis-(3-mercapto-propionate) and 4-(mercaptomethyl)-1,8-dimercapto-3,6-dithiaoctane as preferred compounds for one or the isocyanate-reactive component, and optionally dimethyltin dichloride as a preferred compound of a metal catalyst to accelerate the thermally induced prepolymerization. Possible (weight) proportions are 10.5 parts of 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]-heptane, 25.3 parts of pentaerythritol-tetrakis-(3-mercapto-propionate) and 64.2 parts of 4-(mercaptomethyl)-1,8-dimercapto-3,6-dithiaoctane, as well as 0.01 parts of dimethyltin chloride.The poly(thio-)urethane prepolymer thus obtained with excess thiol as the preferred prepolymer is subsequently provided together with 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]heptane as the preferred compound for the isocyanate component. Possible (weight) fractions are 46.7 parts 2,5- 120816P1423PC Rodenstock GmbH.

[0162] P 2418 PCT - 33 -

[0163] Bis(isocyanatomethyl)-bicyclo-[2.2.1]heptane and 53.3 parts of the prepolymer prepared above. A polyglycol ether consisting of polyethylene glycol units (PEG) and polypropylene glycol units (PPG) is added to the mixture as a preferred surface additive (poloxamer with 31 PPG units and a PEG : PPG ratio of 1 : 2.2), as well as a photochromic naphthopyran dye (possible proportions: 0.66 parts photochromic dye, 10 parts surface additive), which imparts excellent photochromic properties to the mixture after polymerization. This mixture is suitable for forming a particularly photochromic layer 3, which imparts photochromic properties to a substrate 2 coated with it, thereby enabling the production of a preferably photochromic plastic body or a photochromic semi-finished product 1.

[0164] In a subsequent process step S104, the components provided in step S102 for the polymerizable mixture are used, wherein triethylammonium tetraphenyl borate is provided as an additional component as a preferred photobase generator to obtain a photopolymerizable mixture (possible proportion of photobase generator: 0.25). In particular, the triethylammonium tetraphenyl borate, as the preferred photobase generator, transforms the polymerizable mixture into a photopolymerizable mixture, whereby the subsequent polymerization, i.e., the curing of the components of the polymerizable composition, advantageously, and especially preferably, takes place at room temperature, particularly without additional thermal energy input.The triethylammonium tetraphenylborate, the provided photochromic dye, and the provided surface additive, preferably a polyglycol ether consisting of polyethylene glycol units (PEG) and polypropylene glycol units (PPG), are pre-dissolved together in the also provided 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]heptane compound, which is the preferred compound for the isocyanate component, before the prepolymer is added. The components are thoroughly mixed with a magnetic stirrer to obtain a photopolymerizable mixture. 120816P1423PC Rodenstock GmbH.

[0165] P 2418 PCT - 34 -

[0166] In a subsequent process step S106, the photopolymerizable mixture obtained in step S104 is applied to the substrate 2. For this purpose, a casting process is preferred, in which the substrate 2 provided in step S100 is first arranged at a distance from a quartz glass mold, preferably a mineral glass mold, so that a suitable cavity forms between the mineral glass mold and the substrate 2, which has a desired layer thickness of approximately 0.4 mm. This arrangement of the spaced-apart mold and substrate is also referred to as the casting package. The surface of the mineral glass mold, which forms the inner surfaces of the cavity, was previously coated with a water- and grease-repellent film. The photopolymerizable mixture, also referred to as the casting resin, is then placed into the cavity formed between the substrate 2 and the mineral glass mold.

[0167] In the next process step S108, the photopolymerizable mixture is cured. Here, the casting package filled with the photopolymerizable mixture is irradiated with a UV light source, the preferred light source for light-induced curing, to form a cured layer 3. Irradiation with light, particularly UV light, causes the triethylammonium tetraphenylborate, as the preferred photobase generator, to release an amine base. This amine base acts as a catalyst in the curing process and enables the reaction of the monomeric components, such as isocyanates and isocyanate-reactive components, especially thiols, but also prepolymers with corresponding reactive groups, particularly NCO, SH, and / or OH groups, without the need for additional thermal energy. This facilitates the polymerization and curing.Curing of the polymerizable mixture in the filled casting package is ensured, particularly by (UV) light. After complete curing by irradiation, the casting package is demolded, during which the mineral glass mold is removed, yielding a photochromic plastic body or semi-finished product 1 in which an additional layer of a photopolymerizable mixture has formed. The formation of this layer 3 is achieved by irradiation with light and, in particular, without lengthy thermal curing. 120816P1423PC Rodenstock GmbH.

[0168] P 2418 PCT - 35 -

[0169] To ensure the greatest possible clarity, the following paragraphs describe the method according to Figure 3 in conjunction with the object from Figure 4, taking particular account of the fact that an object according to Figure 4 has preferably been or can be manufactured according to a method according to Figure 3.

[0170] Figure 3 shows a schematic drawing of an embodiment of the method for producing a photochromic plastic body or semi-finished product 1 according to one aspect of the invention, as shown in Figure 4, wherein such a plastic body 1 comprises a substrate 2, wherein an additional layer or overlay or also a sprue 3 has been formed on the substrate 2, and wherein the plastic body 1 is provided with an additional coating 4. The method according to Figure 3 represents a further development of the method from Figure 1.

[0171] The previously presented process is further developed in the schematic representation in Figure 3 such that an optional thermal post-treatment step S110 takes place after light curing. Such an optional post-treatment step can be carried out to obtain a stress-free and cured photochromic plastic body or semi-finished product 1. In this step, the resulting plastic body or semi-finished product 1 is stored for several hours, preferably two hours, in a convection oven as the preferred post-treatment device. The heat input at a preferred temperature of approximately 120 °C leads to a reduction of stresses in the formed layer, thereby resulting in a particularly resistant, photochromic plastic body.

[0172] A further development step is S112, in which the resulting photochromic plastic body 1, optionally thermally post-treated in step S110, is provided with (at least) one (further) coating 4. Here, the person skilled in the art can choose from a variety of common coatings and, depending on the type of coating, select the appropriate coating process. For a plastic body or a 120816P1423PC Rodenstock GmbH

[0173] P 2418 PCT - 36 -

[0174] For example, a hard lacquer coating is recommended as an additional coating 4 for semi-finished products 1 made of a plastic material to provide extra hardness and / or scratch protection, giving the plastic body 1 improved protection against scratches. Alternatively or additionally, a buffer lacquer can also be applied as a (or further) additional coating 4, which gives the plastic body 1 increased impact resistance. Hard and / or buffer lacquers are generally applied as part of an immersion coating process, in which the plastic body 1 to be coated is repeatedly immersed in a tank, with the coating forming upon re-immersion.Alternatively or additionally, a plastic body can be provided with an interferometric coating, particularly a multilayer coating, as an additional coating 4, which can modify the reflectivity and / or transmittance of the plastic body 1. For example, reflective coatings, which give the plastic body a desired reflective property, and antireflective coatings, which suppress (disturbing or unwanted) reflection phenomena, are well known as additional coating(s) 4. In particular, such interferometric coatings are generally applied in suitable vacuum coating systems under vacuum conditions by a process of physical vapor deposition or sputtering.

[0175] Figure 5 shows a structural representation or formula of an embodiment of a photobase generator. Photobase generators represent a class of substances characterized by the fact that, upon irradiation with light, particularly UV light, they release a catalytically active species, in particular at least one catalytically active amine, which enables the polymerization process of monomeric components, preferably isocyanates and isocyanate-reactive components, especially thiols, but also of prepolymers with corresponding reactive groups, especially NCO or SH and / or OH groups, without the need for additional thermal energy. Due to their good solubility in the isocyanate components or isocyanate-reactive components, especially thiols, of the mixture, ammonium salts of tetraarylborates are preferred. 120816P1423PC Rodenstock GmbH

[0176] P 2418 PCT - 37 - suitable as photobase generators, in particular salts with ammonium ions containing a tetrasubstituted nitrogen, of which three residues independently have substantially alkyl groups and the remaining residue has substantially hydrogen. In a preferred embodiment, the photobase generator is an ammonium tetraarylborate salt of a tertiary amine according to the formula of Figure 3, wherein the residues Ri, R2 and R3 each independently represent unsubstituted or monosubstituted (C1-C2o) alkyl residues, wherein the substituent can be selected from fluorine, chlorine, bromine, a phenyl residue, a hydroxy residue, a (Ci-C4) alkoxy residue or a polyoxyalkene residue, wherein the alkylene unit has 2 to 4 carbon atoms and the repeating unit n is between 1 and 20; wherein the residue R4 has substantially hydrogen;wherein the residues Rs, Re, Ry and Rs each independently represent phenyl residues having between zero and four substituents, or naphthyl residues having between zero and two substituents, wherein the substituents may be selected from fluorine, chlorine, bromine, a phenyl residue, a (Ci-C4) alkyl residue, a (Ci-C4) alkoxy residue or a trifluoromethyl residue.

[0177] Preferably, the residues Ri, R2, and R3 differ from one another, i.e., they are distinct. Alternatively, they can preferably, and in particular all of them, be identical. In a further development of this, two or three residues can preferably form one or more cycles together.

[0178] Preferably, the residues Rs, Re, R7 and Rs differ from each other, i.e., they are distinct. Alternatively, they can preferably, and in particular all of them, be identical to each other.

[0179] The invention is explained in more detail below using examples, without, however, being limited to these examples. 120816P1423PC Rodenstock GmbH

[0180] P 2418 PCT - 38 -

[0181] Example A: Manufacturing a photochromic spectacle lens using the Anquss method

[0182] To obtain a photochromic spectacle lens, a substrate was first provided, consisting of a polythiourethane disc approximately 4 mm thick. The substrate was spaced apart from a quartz glass mold, preferably a mineral glass mold, such that a suitable cavity formed between the mold and the substrate, with the desired layer thickness of approximately 0.4 mm. This arrangement is also referred to as a casting package. The surface of the mineral glass mold, which formed the inner surfaces of the cavity, was previously coated with a water- and grease-repellent film. A preferred mixture consisting of 46.7 parts of 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.[1]heptane as the preferred compound for the isocyanate component, 53.3 parts of a preferred prepolymer comprising an excess of isocyanate-reactive components, 0.25 parts of triethylammonium tetraphenyl borate as the preferred photobase generator, a block polyglycol ether consisting of polyethylene glycol units (PEG) and polypropylene glycol units (PPG) as the preferred surface additive, and a photochromic naphthopyran dye. The exact composition and the proportions of the last two components mentioned are given in Table 1.

[0183] To prepare the prepolymer, a reactor was equipped with 10.5 parts of 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]heptane as a preferred compound for one or the isocyanate component, 25.3 parts of pentaerythritol tetrakis-(3-mercaptopropionate) and 64.2 parts of 4-(mercaptomethyl)-1,8-dimercapto-3,6-dithiaoctane as preferred compounds for one or the isocyanate-reactive component, and 0.01 parts of dimethyltin dichloride as a preferred compound of an optional metal catalyst to accelerate the thermally induced prepolymerization of the prepolymer. The components were heated to 80 °C with continuous stirring and stirred at this temperature for approximately 7 h. The prepolymer thus obtained was combined with a 120816P1423PC Rodenstock GmbH

[0184] P 2418 PCT - 39 -

[0185] Excess thiol components (and thus isocyanate-reactive groups) were available for use in a polymerizable mixture after cooling to room temperature.

[0186] To prepare the photopolymerizable mixture, the triethylammonium tetraphenylborate, the surface additive, and the photochromic naphthopyran dye were first dissolved in 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]heptane before the remaining components mentioned above were added. The components were thoroughly mixed with a magnetic stirrer to obtain a photopolymerizable mixture. The photopolymerizable mixture obtained in this way was placed into the previously formed cavity between the substrate and the mineral glass mold. The photopolymerizable mixture was then cured by irradiation with UV light. For this purpose, the filled casting package, consisting of the substrate, the mineral glass mold, and the photopolymerizable mixture, was irradiated with UV light from a Herolab UV-6 S / L lamp (254 nm mode) at a distance of approximately 15 mm for about 1 hour to obtain a cured semi-finished product.The semi-finished product thus obtained was then separated from the mineral glass mold and thermally post-treated at about 120 °C for about 2 hours in a convection oven to obtain a hardened and stress-free and in particular photochromic plastic body.

[0187] In this way, a photochromic plastic body was produced using the presented method, which was particularly suitable for later use as a spectacle lens.

[0188] Example B – Manufacturing a photochromic spectacle lens using a spin coating process

[0189] An approximately 4 mm thick polythiourethane disc was provided as a suitable substrate and placed in a spin coating device (spin coater). To obtain, form, or deposit a photochromic layer on the provided substrate, an example mixture consisting of 39.4 parts of 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]-heptane was used as a preferred 120816P1423PC Rodenstock GmbH

[0190] P 2418 PCT - 40 -

[0191] The compound, comprising 60.6 parts of a prepolymer, contains an excess of isocyanate-reactive components, 0.25% triethylammonium tetraphenylborate as the preferred photobase generator, a block polyglycol ether as a surface additive consisting of polyethylene glycol units (PEG) and polypropylene glycol units (PPG), and a photochromic naphthopyran dye. The exact composition and proportions of the last two components are given in Table 1.

[0192] To prepare the prepolymer, a reactor was equipped with 19 parts of 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]heptane as a preferred compound for one or the isocyanate component, 22.9 parts of pentaerythritol tetrakis-(3-mercaptopropionate), and 58.1 parts of 4-(mercaptomethyl)-1,8-dimercapto-3,6-dithiaoctane as preferred compounds for one or the isocyanate-reactive component, and 0.01 parts of dimethyltin dichloride as a preferred compound of an optional metal catalyst to accelerate the thermally induced prepolymerization of the prepolymer. The components were heated to 80 °C with continuous stirring and stirred at this temperature for approximately 7 h. The resulting prepolymer with an excess of thiol components (and thus isocyanate-reactive groups) was available for use in a polymerizable mixture after cooling to room temperature.

[0193] To prepare the photopolymerizable mixture, the photochromic dye, the surface additive, and the triethylammonium tetraphenylborate were first dissolved in 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]heptane before the prepolymer was added to the mixture. The components were thoroughly mixed with a magnetic stirrer to obtain a photopolymerizable mixture. The photopolymerizable mixture was applied to the substrate, which was rotating at approximately 600 revolutions per minute in the spin coating apparatus, to form a photochromic layer with a thickness of approximately 40 pm on the substrate. The resulting semi-finished product, consisting of the substrate and the photochromic layer, was then cured with UV light to produce a semi-finished product with a fully cured photochromic layer. 120816P1423PC Rodenstock GmbH

[0194] P 2418 PCT - 41

[0195] For this purpose, the semi-finished product was irradiated with UV light for about 30 minutes using a Herolab UV-6 S / L lamp (254 nm mode) at a distance of about 15 mm.

[0196] The semi-finished product was then thermally post-treated to obtain a hardened and stress-free plastic body, for which the semi-finished product was placed in a convection oven at about 110 °C for approximately 2 hours.

[0197] In this way, a photochromic plastic body was produced using the presented method, in particular by applying a photopolymerizable mixture to a provided substrate by means of spin coating, wherein the produced plastic body was particularly suitable for later use as a spectacle lens.

[0198] In example B (Table 1, No. 10), produced using a spin coating process, a significantly higher dye concentration (3.9 parts) must be selected due to the reduced layer thickness. Consequently, the ratio of photochromic dye to surface additive must also be adjusted. Essentially, the proportion of surface additive must be considerably increased compared to larger layer thicknesses.

[0199] The transmission data in Table 1 are from measurements carried out according to the standard DIN EN ISO 8980-3 at 23°C.

[0200] The lightening behavior from the completely darkened state of the compounds according to the invention is also listed in Table 1. The measure of lightening behavior is defined as the percentage relative increase in transmission after 2 minutes of lightening, normalized to the total photochromic range of complete lightening. This practically relevant quantity for describing the photochromic kinetics is here referred to as relative lightening F min.

[0201] Here, TO is the light transmittance in the unexcited state; ts is the light transmittance in the darkened state;

[0202] T2 min, the light transmittance after 2 minutes of brightening from a darkened state, 120816P1423PC Rodenstock GmbH

[0203] P 2418 PCT - 42 -

[0204] Condition.

[0205] The stated percentage value is calculated from the transmission data of the phototropic kinetic measurement according to DIN EN ISO 8980-3 at 23°C. In the first step, the transmission difference between the state after 2 minutes of brightening and the previously achieved darkened state is determined; in the second step, the transmission difference between the brightened and darkened states is determined. The ratio of the two transmission differences is multiplied by 100 to obtain a percentage value. A value of 50% for R2 min means that after 2 minutes of brightening, half of the photochromic stroke to the fully brightened state has already been completed. The higher the percentage value, the faster the brightening process.

[0206] 120816P1423PC Rodenstock GmbH

[0207] P 2418 PCT - 43 -

[0208] Table 1: Overview of the composition of the photopolymerizable mixtures and the material and photochromic properties of the photochromic plastic bodies obtained therefrom. The surface additives are named according to the trade names under which the BASF Group markets the block polyglycol ethers (called Pluronics).

Claims

120816P1423PC Rodenstock GmbH P 2418 PCT - 44 - Patent claims 1. Photopolymerizable mixture, wherein the mixture comprises at least one photochromic dye, comprising at least one photochromic center to which at least one polymer chain is bonded, preferably exactly one polymer chain, comprising at least 4, preferably at least 8, repeating units, and at least one surface additive; and further comprising at least two of the following components: A poly(thio-)urethane prepolymer prepared from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is such that there is an excess of isocyanate-reactive groups compared to isocyanate groups; A poly(thio-)urethane prepolymer prepared from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is such that there is an excess of isocyanate groups compared to isocyanate-reactive groups; a thiol component and an isocyanate component; wherein the ratio of isocyanate groups to thiol groups / isocyanate-reactive groups is 0.95:1 to 1:0.95; and wherein the mixture additionally comprises at least one photobase generator.

2. Photopolymerizable mixture according to claim 1, wherein at least one isocyanate component is or comprises isophorone diisocyanate, 2,5-bis(isocyanatomethyl)-bicyclo-[2.2.1]heptane, 4,4'-diphenylmethane diisocyanate, 4,4-dicyclohexanemethane diisocyanate, toluene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, 1,3-bis(isocyanatomethyl)benzene or 1,6-diisocyanatohexane.

3. Photopolymerizable mixture according to claim 1 or 2, wherein at least one isocyanate-reactive component or thiol component is pentaerythritol- 120816P1423PC Rodenstock GmbH P 2418 PCT - 45 - tetrakis-(3-mercapto-propionate), 4-(mercaptomethyl)-1 ,8-dimercapto-3,6-dithiaoctane or 4,8-dimercaptomethyl-1 ,11 -dimercapto-3,6,9-trithiaundecane is or contains.

4. Photopolymerizable mixture according to at least one of claims 1 to 3, wherein at least one isocyanate component is a prepolymer formed from isocyanate components and isocyanate-reactive components, having an excess of isocyanate groups compared to isocyanate-reactive groups, preferably wherein the proportion of the isocyanate components in the prepolymer is selected such that the isocyanate groups present in the mixture correspond to up to 50%, preferably up to 30%, of the isocyanate-reactive groups contained in the mixture;or wherein at least one isocyanate-reactive component is a prepolymer formed from isocyanate components and isocyanate-reactive components, having an excess of isocyanate-reactive groups compared to isocyanate groups, preferably wherein the proportion of the isocyanate-reactive components in the prepolymer is selected such that the isocyanate-reactive groups present in the mixture correspond to up to 50%, preferably up to 30%, of the isocyanate groups contained in the mixture.

5. Photopolymerizable mixture according to at least one of claims 1 to 4, wherein the photochromic center of the photochromic dye is selected from one or more of the following classes of compounds: naphthopyrans, spirooxazines or spiropyrans, wherein preferably the at least one polymer chain, more preferably exactly one polymer chain which is bonded to the photochromic center of the at least one photochromic dye, has at least 4, preferably at least 8 and at most 45 repeating units, wherein preferably the at least one polymer chain consists substantially of polypropylene glycol monoalkyl ether.

6. Photopolymerizable mixture according to at least one of claims 1 120816P1423PC Rodenstock GmbH P 2418 PCT - 46 - to 5, wherein the at least one surface additive is a poloxamer comprising repeating units of polyethylene glycol (PEG) and polypropylene glycol (PPG), wherein these units are arranged in blocks as PEG / PPG / PEG with terminal PEG blocks at both ends of the chain, and a central PPG block.

7. Photopolymerizable mixture according to at least one of claims 1 to 6, wherein the polymer chain of the photochromic dye has 4 to 18 repeat units, preferably 8 to 18 repeat units, and the at least one surface additive is a poloxamer, comprising 13 to 21 PPG units, wherein the ratio of PEG units : PPG units in the poloxamer is 1 :1 to 1 :8, and wherein the molar ratio of photochromic dye : surface additive is 1 :1 to 1 :90; or wherein the polymer chain of the photochromic dye has 4 to 18 repeat units, preferably 8 to 18 repeat units, and the at least one surface additive is a poloxamer with 22 to 40 PPG units, wherein the ratio of PEG units : PPG units in the poloxamer is 3:1 to 1:16, and wherein the molar ratio of photochromic dye : surface additive is 1:1 to 1:90;or wherein the polymer chain of the photochromic dye has 19 to 45 repeat units, and the at least one surface additive is a poloxamer with 22 to 42 PPG units, wherein the ratio of terminal PEG units : central PPG units in the poloxamer is 3:1 to 1:2.5, and wherein the molar ratio of photochromic dye : surface additive is 1:1 to 1:

90.

8. Photopolymerizable mixture according to at least one of claims 1 to 7, wherein the mixture comprises at least one of the following 120816P1423PC Rodenstock GmbH P 2418 PCT - 47 - The product contains components: at least one dye which is different from the photochromic dye; at least one UV absorber; and / or at least one photosensitizer; and / or at least one metal catalyst; and / or at least one surfactant.

9. Photopolymerizable mixture according to at least one of claims 1 to 8, wherein the photobase generator is an ammonium salt, preferably an ammonium salt of tetraaryl borate.

10. Photopolymerizable mixture according to at least one of claims 1 to 9, wherein the proportion of the photobase generator in the mixture is less than or equal to 10 parts, preferably less than or equal to 5 parts, particularly preferably less than or equal to 1 part, most preferably less than or equal to 0.5 parts, in particular exactly 0.25 parts.

11. Photopolymerizable mixture according to at least one of claims 1 to 10, wherein the photobase generator is selected from an ammonium tetraaryl borate salt of a tertiary amine according to formula (I): Ri ^8 R-4- R 2 7 — B—5(I) R3 Rß wherein the residues Ri, R2 and R3 each independently represent unsubstituted or monosubstituted (Ci-C2o) alkyl residues, wherein the substituent is from fluorine, chlorine, bromine, a phenyl residue, a hydroxy residue, a (Ci-C4) alkoxy residue or a polyoxyalkene residue, where here the alkylene unit 2 to 4 The compound has carbon atoms and the repeating unit n is between 1 and 20; the residue R4 is essentially hydrogen; 120816P1423PC Rodenstock GmbH P 2418 PCT - 48 - wherein the residues Rs, Re, Ry and Rs each independently represent phenyl residues having between zero and four substituents, or naphthyl residues having between zero and two substituents, wherein the substituents may be selected from fluorine, chlorine, bromine, a phenyl residue, a (Ci-C4) alkyl residue, a (Ci-C4) alkoxy residue or a trifluoromethyl residue; wherein the at least one photobase generator is preferably selected from triethylammonium tetraphenylborate, diisopropylethylammonium tetraphenylborate, dimethylcyclohexyl tetraphenylborate or dimethylcyclohexyl tetraphenylborate or mixtures thereof.

12. A process for producing a semi-finished product comprising the following steps: Providing a substrate (S100); Providing a polymerizable mixture of isocyanates and isocyanate-reactive components (S102) as defined in the preceding claims, wherein the mixture: comprises at least one photochromic dye, at least one photochromic center to which at least one polymer chain is bonded, preferably exactly one polymer chain, comprising at least 8 repeating units, and at least one surface additive, and comprising at least two of the following components: A poly(thio-)urethane prepolymer prepared from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is such that there is an excess of isocyanate-reactive groups compared to isocyanate groups; A poly(thio-)urethane prepolymer prepared from isocyanates and isocyanate-reactive components, wherein the ratio of the two components is such that there is an excess of isocyanate groups compared to isocyanate-reactive groups; a thiol component and an isocyanate component; wherein the ratio of isocyanate groups to thiol groups / isocyanate- 120816P1423PC Rodenstock GmbH P 2418 PCT - 49 - reactive groups 0.95:1 to 1 :0.95 is; Mixing (S104) this polymerizable mixture with at least one further additive, wherein this additive is or has a photobase generator, to obtain a photopolymerizable mixture; Application (S106) of the photopolymerizable mixture to the substrate; Curing (S108) of the photopolymerizable mixture by exposure to light, in particular UV light, to form a semi-finished product or plastic body.

13. Method according to claim 12, wherein the application of the (photo-)polymerizable mixture is carried out by spin coating or by casting.

14. Method according to claim 12 or 13, wherein, after irradiation with light, in particular with UV light, an additional thermal curing of the mixture takes place.

15. Method according to at least one of the preceding claims 12 to 14, wherein the procedure additionally includes at least one of the following steps: Thermal post-treatment (S110) of the semi-finished product to obtain a plastic body; and / or Forming (S112) at least one coating on the plastic body or semi-finished product.

16. Semi-finished product manufactured according to a process according to any one of claims 12 to 15.

17. Plastic body, in particular spectacle lens, which is made from a semi-finished product according to claim 16.

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