Optical material with improved colour

Abstract

Disclosed are polymerizable compositions for ophthalmic lenses. The compositions employ peroxide-based polymerization initiators with decreased capacity for dye degradation. The compositions enable the inclusion of color-balancing dyes, resulting in lenses with improved clarity and color balance.

Claims

1. A polymerizable composition comprising: a) at least one allyl monomer or oligomer; b) at least one catalyst suitable for initiating the polymerization of said allyl monomer or oligomer; c) at least one UV absorber; and d) at least one dye; wherein the at least one catalyst has the following formula:
R.sub.1—O—O—C(═O)—O—R.sub.2 or R.sub.1—O—O—C(═O)—R.sub.2 wherein R.sub.1 is an alkyl chain having from 1 to 12 carbon atoms and R.sub.2 is a multivalent polyether bound to a plurality of alkylperoxy carbonate groups; or wherein R.sub.2 is an alkyl chain having from 1 to 12 carbon atoms and R.sub.1 is a multivalent polyether bound to a plurality of alkylperoxy carbonate groups.

2. The polymerizable composition of claim 1, wherein the allyl monomer or oligomer is ethylene glycol bis(allyl carbonate) or diethylene glycol bis(allyl carbonate), or an oligomer thereof, or a mixture thereof.

3. The polymerizable composition of claim 1, wherein the at least one allyl monomer or oligomer is present in an amount ranging from 20 to 99.5% by weight, based on a total weight of the composition.

4. The polymerizable composition of claim 1, wherein the catalyst R.sub.1 and R.sub.2 groups are saturated.

5. The polymerizable composition of claim 1, wherein the catalyst alkyl chain comprises 3 to 8 carbon atoms.

6. The polymerizable composition of claim 1, wherein the UV absorber is a benzophenone having the following structure: ##STR00003## wherein R.sub.3 and R.sub.4 are each independently H or an alkyl chain having from 1 to 12 carbon atoms.

7. The polymerizable composition of claim 6, wherein R.sub.3 and R.sub.4 are methyl.

8. The polymerizable composition of claim 6, wherein R.sub.3 and R.sub.4 are H.

9. The polymerizable composition of claim 1, wherein R.sub.1 or R.sub.2 is bound to 2, 3 or 4 alkylperoxy carbonate groups.

10. A process for the manufacture of an ophthalmic lens, comprising polymerizing the polymerizable composition of claim 1 to form an ophthalmic lens.

11. An ophthalmic lens obtained by polymerizing a polymerizable composition comprising: a) at least one allyl monomer or oligomer; b) at least one catalyst suitable for initiating the polymerization of said allyl monomer or oligomer; c) at least one UV absorber; and d) at least one dye; wherein the at least one catalyst has the following formula:
R.sub.1—O—O—C(═O)—O—R.sub.2 of R.sub.1—O—O—C(═)—R.sub.2 wherein R.sub.1 is an alkyl chain having from 1 to 12 carbon atoms and R.sub.2 is a multivalent polyether bound to a plurality of alkylperoxy carbonate groups; or wherein R.sub.2 is an alkyl chain having from 1 to 12 carbon atoms and R.sub.1 is a multivalent polyether bound to a plurality of alkylperoxy carbonate groups.

12. The ophthalmic lens of claim 11, wherein the lens has a yellow index of less than 5.

13. The ophthalmic lens of claim 11, wherein the lens has a haze value of less than 0.5%.

14. The ophthalmic lens of claim 11, wherein the lens has a light-cut value of less than 410 nm.

15. The ophthalmic lens of claim 11, wherein R.sub.1 or R.sub.2 is bound to 2, 3 or 4 alkylperoxy carbonate groups.

16. The polymerizable composition of claim 1, wherein said polyether has from 5 to 30 carbon atoms.

17. The polymerizable composition of claim 1, wherein the at least one allyl monomer or oligomer is present in an amount ranging from 50 to 99.5% by weight, based on a total weight of the composition.

18. The polymerizable composition of claim 1, wherein the at least one allyl monomer or oligomer is present in an amount ranging from 80 to 99.5% by weight, based on a total weight of the composition.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a graph comparing blue cut performance to yellow index cost for a series of blue-cutting agents.

DETAILED DESCRIPTION

(2) Various features and advantageous details are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. It should be understood, however, that the detailed description and the specific examples, while indicating embodiments, are given by way of illustration only, and not by way of limitation. Various substitutions, modifications, additions, and/or rearrangements will be apparent to those of ordinary skill in the art from this disclosure.

(3) In the following description, numerous specific details are provided to provide a thorough understanding of the disclosed embodiments. One of ordinary skill in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

(4) The polymerizable compositions disclosed herein employ a polymerizable initiator with a decreased capacity for dye degradation over traditionally-employed allyl monomer polymerization initiators, e.g., IPP. The disclosed initiators preserve effectiveness at catalyzing polymerization while exhibiting little to no degradation of dyes. The disclosed polymerizable compositions therefore enable the use of color-balancing dyes with minimized risk for dye degradation.

(5) The term “saturated” as used herein means the compound or group so modified has no carbon-carbon double and no carbon-carbon triple bonds, except as noted below. The term does not preclude carbon-heteroatom multiple bonds, for example a carbon oxygen double bond or a carbon nitrogen double bond. Moreover, it does not preclude a carbon-carbon double bond that may occur as part of keto-enol tautomerism or imine/enamine tautomerism. Aliphatic compounds/groups can be saturated, that is joined by single bonds (alkanes/alkyl), or unsaturated, with one or more double bonds (alkenes/alkenyl) or with one or more triple bonds (alkynes/alkynyl).

(6) The term “alkyl” when used without the “substituted” modifier refers to a monovalent saturated aliphatic group with a carbon atom as the point of attachment, a linear or branched, cyclo, cyclic or acyclic structure, and no atoms other than carbon and hydrogen. Thus, as used herein cycloalkyl is a subset of alkyl. The groups —CH.sub.3 (Me), —CH.sub.2CH.sub.3 (Et), —CH.sub.2CH.sub.2CH.sub.3 (n-Pr), —CH(CH.sub.3).sub.2 (iso-Pr), —CH(CH.sub.2).sub.2 (cyclopropyl), —CH.sub.2CH.sub.2CH.sub.2CH.sub.3 (n-Bu), —CH(CH.sub.3)CH.sub.2CH.sub.3 (sec-butyl), —CH.sub.2CH(CH.sub.3).sub.2 (iso-butyl), —C(CH.sub.3).sub.3 (tert-butyl), —CH.sub.2C(CH.sub.3).sub.3 (neo-pentyl), —CH.sub.2CH(C.sub.2H.sub.5)CH.sub.2CH.sub.2CH.sub.2CH.sub.3 (2-ethylhexyl), cyclobutyl, cyclopentyl, cyclohexyl, and cyclohexylmethyl are non-limiting examples of alkyl groups. The term “polyether” refers to a functional group having two or more oxygen atoms (poly), wherein each oxygen atom is bound to two alkyl carbons (ether). In some embodiments, a polyether may be obtained by polymerization of a polyol with two or more alkylene oxides. Polyethers may be linear or branched. Non-limiting examples of polyether groups are polymers or copolymers of ethylene oxide, propylene oxide and butylene oxide. Other suitable polyethers groups are obtained by reaction of a polyol with ethylene oxide, propylene oxide, butylene oxide or mixtures thereof. Non limiting examples of polyol are trimethylolpropane, pentaerythritol. When any of these terms is used with the “substituted” modifier one or more hydrogen atom has been independently replaced by —OH, —F, —Cl, —Br, —I, —NH.sub.2, —NO.sub.2, —CO.sub.2H, —CO.sub.2CH.sub.3, —CN, —SH, —OCH.sub.3, —OCH.sub.2CH.sub.3, —OCH.sub.2CH.sub.2OH, —C(O)CH.sub.3, —NC(O)CH.sub.3, —N(CH.sub.3).sub.2, —C(O)NH.sub.2, —OC(O)CH.sub.3, —S(O).sub.2NH.sub.2, or imidazolidinone. The following groups are non-limiting examples of substituted alkyl groups: —CH.sub.2OH, —CH.sub.2Cl, —CF.sub.3, —CH.sub.2CN, —CH.sub.2C(O)OH, —CH.sub.2C(O)OCH.sub.3, —CH.sub.2C(O)NH.sub.2, —CH.sub.2C(O)CH.sub.3, —CH.sub.2OCH.sub.3, —CH.sub.2OC(O)CH.sub.3, —CH.sub.2NH.sub.2, —CH.sub.2N(CH.sub.3).sub.2, and —CH.sub.2CH.sub.2Cl.

Examples

(7) Preparation of Polymerization Compositions

(8) The polymerizable compositions described below included at least one allyl monomer, a blue-cutting agent, and at least one color-balancing material in combination with a peroxide initiator. Additional additives were included in some examples.

(9) The polymerizable compositions were produced by weighing and mixing the ingredients in a beaker. CR39® (allyl monomer 1), optional CR39E® (allyl monomer 2, as disclosed in U.S. Pat. No. 7,214,754), and optional surfactant were first mixed. Once homogeneous, a blue-cutting agent was then added and the beaker contents were is mixed again until the blue-cutting agent was completely dissolved. Color balancing materials (C.I. Pigment violet 15, BL-1), or a combination of dyes (Solvent Red 195/Solvent Blue 128 or Solvent Violet 56/Solvent Blue 128) were then introduced. Finally, initiator (IPP or TBIC) was added and the mixture was stirred thoroughly, degassed, and filtered.

(10) TABLE-US-00001 TABLE 1 Polymerizable Composition Preparation Example I-1 I-2 I-3 C-4 C-5 I-6 CR-39 (allyl monomer 1) 99.2 94.2 92.2 94.5 94.5 94.2 CR-39 E (allyl monomer 2) 2.0 2.0 KF-353A (releasing agent) 0.1 0.1 0.1 0.1 Seesorb 107 (UV absorber) 0.3 0.3 0.3 0.3 0.3 0.3 TBIC (initiator) 0.4 0.4 0.4 0.4 IPP (control initiator) 3.21 3.21 Solvent Violet 59 (Color-balancing 1.5 dye, 0.01% in CR-39) Solvent Red 195 (Color-balancing 2.5 3.5 dye, 0.01% in CR-39) Solvent Blue 128 (Color-balancing 2.5 3.5 3.5 dye, 0.01% in CR-39) BL-1 (Color-balancing pigment, 1% 1.5 in CR-39) Total 100 100 100 100 100 100
Casting and Polymerization

(11) Molds were filled with polymerizable compositions using a cleaned syringe. The polymerization was carried out in a regulated electronic oven in which the temperature was gradually increased from 45° C. to 130° C. in 15 hours then kept constant at 130° C. for 6 hours.

(12) Lens Characterization

(13) The following parameters were measured (all on piano lenses having 2 mm thickness center):

(14) 1. Light-cut: highest wavelength for which transmittance is lower than 1%

(15) 2. Blue cut: measured through the average transmittance TmB of the ophthalmic lens over the range 420-450 nm

(16) 3. Yellow index (YI): colorimetric calculation from tristimulus values (X, Y, Z) according to ASTM D1003 standard

(17) 4. Haze: mesured using Hazeguard XL-211, according to ASTM D1003-00

(18) Results

(19) Examples C-4 and C-5 employed diisopropyl peroxydicarbonate (IPP), a relatively reactive polymerization initiator which has been shown to degrade dyes and negatively affect color balance and lens clarity. As depicted in Table 2, Example 4-C exhibits high haze, which results from bluing pigment-induced light scattering.

(20) TABLE-US-00002 TABLE 2 Results Example I-1 I-2 I-3 C-4 C-5 I-6 Light-Cut (nm) 402 402 402 404 403 402 TvD65 (%) 92.03 89.57 88.93 88.59 92.0 87.9 YI 4.84 3.61 3.01 3.30 6.6 2.35 L* 96.78 95.80 95.54 95.40 96.8 95.14 a* −2.06 −1.85 −1.79 −2.56 −2.8 −2.03 b* 4.13 3.35 2.99 3.63 5.6 2.77 Haze (%) 0.19 0.21 0.19 0.61 0.1 0.30 TmB (%) 85.16 83.94 83.85 81.42 81.2 83.08

(21) In order to eliminate IPP-induced degradation of color-balancing additives or pigment-induced light scattering, Example C-5 contained no coloring materials. Due to the lack of a color-balancing material, Example C-5 exhibited yellow index (YI) that was significantly higher than other examples.

(22) Example I-1 included the initiator TBIC, a blue-cutting agent (Seesorb 107), and no bluing agents. The blue-cutting agent was used to reach a TmB of 85%. Example 1-1 exhibited a low haze value of 0.19%, however, yellow index was high at 4.8, owing to a lack of bluing agents. By contrast, Example C-4 employed a color-balancing pigment and exhibited a relatively low yellow index of 3.3, but a high haze value of 0.61%.

(23) Example I-2 included the initiator TBIC, a blue-cutting agent, and bluing agents. As demonstrated in Table 2, Example 1-2 exhibited a low yellow index of 3.61, owing to the inclusion of color-balancing bluing agents. Importantly, Example I-2 exhibited a low haze value of 0.21%. Despite the inclusion of color balancing dye molecules, which may be degraded by harsh polymerization initiators, Example I-2 demonstrated low haze. The relatively mild polymerization initiators disclosed herein allow for the use of color balancing dyes to provide lenses exhibiting a superior combination of low haze and low yellow index. Examples I-3 and I-6 demonstrate comparable results using other color-balancing dyes: a good balance between low haze and yellow index.

(24) A number of blue-cutting agents were evaluated for blue-cutting performance versus yellow index, without color-balancing agents. As depicted in FIG. 1 (obtained with IPP or TBIC initiator) the blue-cutting agent Seesorb 107, a benzophenone, demonstrated the lowest TmB (a measure of blue-cut performance) at the lowest yellow index cost. Eversorb 109 and Seesorb 106 demonstrated a good balance between TmB and Yellow Index, as compared to standard UV absorbers such as Seesorb 709 or Tinogard TL, which were not able to provide TmB values below 85%. Other UV absorbers such as Eversorb 74 or Eversorb 81 (both benzotriazole type) were able to provide low TmB values (lower than 85%) but with much higher Yellow Index. Lens Examples I-2, I-3, and I-6 employed the best-performing UV absorbers and color-balancing agents, along with the presently-claimed catalysts.

(25) In summary, the relatively mild polymerization initiators disclosed herein exhibit reduced degradation of color-balancing dyes. The polymization initiators allow for the use of blue-cutting agents in combination with color-balancing dyes to provide lenses exhibiting a superior combination of blue cut performance, low haze, and low yellow index.

(26) The claims are not to be interpreted as including means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively.