Use of benzoyl peroxide as initiator to make allyl lenses with improved color

Abstract

The present disclosure relates to a method for manufacturing a lens, the method comprising the steps of: a. Providing at least one allyl monomer or allyl oligomer of a mass m of allyl, b. Providing a free radical initiator composition comprising benzoyl peroxide (BPO) in the form of a mixture with water, c. C. Mixing the at least one allyl monomer or allyl oligomer with the free-radical initiator composition to obtain a polymerizable composition, d. Stripping water from the polymerizable composition to obtain a dried polymerizable composition, e. Providing a mold assembly and filling the mold assembly with the dried polymerizable composition, e. Forming the mold assembly, and e. Forming the mold assembly. F. Curing the dried polymerizable composition in the mold assembly to obtain the lens. The present invention also provides a polymerizable composition for making a lens characterized by reduced yellowness.

Description

Technical Field

[0001] The present disclosure relates to a method for making a lens comprising polymerizing at least one allylic monomer or allylic oligomer using benzoyl peroxide as a free radical initiator. This method produces a lens with improved color. Background Art

[0002] It is very common to manufacture lenses (eg ophthalmic lenses) by free radical polymerization of allylic monomers and / or oligomers (eg CR39).

[0003] CR39 is a blend of allylic monomers and oligomers derived from diethylene glycol bis(allyl carbonate).

[0004]

[0005] The standard free radical initiator used in the polymerization of allylic monomers and oligomers such as CR39 is diisopropyl peroxydicarbonate (IPP). However, the manufacture of IPP and its handling raises several safety issues. Isopropyl chloroformate (IPCF) used in the synthesis of IPP is a highly flammable material, and IPP itself lacks stability at ambient temperature (IPP has a half-life of one hour at 56°C). Therefore, the handling of IPP, for example during the preparation of CR39-based lenses, requires the use of a cooling system.

[0006] Benzoyl peroxide (BPO) is considered as a possible alternative to IPP, which avoids these problems. Its synthesis does not require the use of IPCF, and it is more stable than IPP, with a half-life of one hour at 92°C.

[0007]

[0008] In dry form, BPO is a very dangerous material. When heated above its melting point (103°C), it explodes spontaneously, which can occur due to simple friction or due to impact. However, when mixed with a large excess of water, BPO can be handled safely even at room temperature. Commercially, BPO is typically sold in the form of a paste or in the form of granules containing about 75% BPO and about 25% water by mass.

[0009] One problem with using BPO as a free radical initiator when producing lenses from allylic monomers and oligomers such as CR39 is that the resulting lenses have a relatively high yellowness index (YI), which makes these lenses unacceptable to most consumers.

[0010] The present disclosure provides a method for making a lens comprising polymerizing at least one allylic monomer or allylic oligomer using benzoyl peroxide as a free radical initiator, which unexpectedly produces a lens having improved color. Summary of the invention

[0011] This article discloses the following items.

[0012] A. A method for manufacturing a lens, the method comprising the following steps:

[0013] a. Provide a certain quality m 烯丙基 at least one allylic monomer or allylic oligomer,

[0014] b. providing a free radical initiator composition comprising benzoyl peroxide (BPO) mixed with water,

[0015] c. mixing said at least one allylic monomer or allylic oligomer with the free radical initiator composition to obtain a polymerizable composition,

[0016] d. stripping water from the polymerizable composition to obtain a dried polymerizable composition,

[0017] e. providing a mold assembly and filling the mold assembly with the dried polymerizable composition,

[0018] f. curing the dried polymerizable composition in the mold assembly to obtain the lens.

[0019] B. The method according to item A, wherein the lens is an ophthalmic lens.

[0020] C. A method according to item A or item B, wherein the at least one allylic monomer or allylic oligomer is provided as part of an allyl composition, the allyl composition comprising greater than 95%, particularly greater than 97%, more particularly greater than 99% by mass of the at least one allylic monomer or allylic oligomer relative to the total mass of the allyl composition.

[0021] D. The method according to any of items AC, wherein the at least one allylic monomer or allylic oligomer is provided as part of an allylic composition comprising 0.003% to 0.04% by mass of water relative to the total mass of the allylic composition.

[0022] E. The method according to any one of items AD, wherein the at least one allylic monomer or allylic oligomer is a compound or a mixture of compounds, wherein all these compounds each contain at least two allyl groups.

[0023] F. The method according to any one of items AE, wherein the at least one allylic monomer or allylic oligomer comprises 烯丙基 At least 90%, more particularly 95% to 99%, by mass, of a compound selected from the group consisting of diethylene glycol bis(allyl carbonate), oligomers of diethylene glycol bis(allyl carbonate), ethylene glycol bis(allyl carbonate), oligomers of ethylene glycol bis(allyl carbonate), bisphenol A bis(allyl carbonate), oligomers of bisphenol A bis(allyl carbonate), diallyl phthalate, diallyl isophthalate, diallyl terephthalate and mixtures thereof.

[0024] G. The method according to any one of items AF, wherein the at least one allylic monomer or allylic oligomer comprises 烯丙基 1 to 10%, specifically 1 to 5% by mass of a monomer represented by formula (I):

[0025]

[0026] Where R 2 is a polyvalent linking group without a carbamate bond; R 3 is a residue of a substance having a single hydroxyl group and at least one allyl group, R does not contain a urethane bond, and j is a number from 2 to 4.

[0027] H. The method according to item G, wherein R 2 is the residue of an alicyclic diisocyanate selected from the group consisting of isophorone diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, bis(isocyanatomethyl)cyclohexane, bis(isocyanatocyclohexyl)methane, bis(isocyanatocyclohexyl)-2,2-propane, bis(isocyanatocyclohexyl)-1,2-ethane and mixtures thereof, and j is 2.

[0028] I. The method according to item G or item H, wherein R 3 is a residue selected from the group consisting of C2-C4 alkylene glycol allyl ether, poly(C2-C4 alkylene glycol) allyl ether (such as a residue selected from the group consisting of poly(ethylene glycol) allyl ether, poly(1,2-propylene glycol) allyl ether, and mixtures thereof), trimethylolpropane di(allyl ether), trimethylolethane di(allyl ether), pentaerythritol tri(allyl ether), di-trimethylolpropane tri(allyl ether), and mixtures thereof.

[0029] J. The method according to any one of items GI, wherein the at least one allylic monomer or allylic oligomer comprises relative to m 烯丙基95 to 99% by mass of a mixture of diethylene glycol bis(allyl carbonate) and oligomers of diethylene glycol bis(allyl carbonate), and relative to m 烯丙基 1 to 5% by mass of monomers of formula (I).

[0030] K. The method according to J, wherein diethylene glycol bis(allyl carbonate) accounts for 90% to 99% of the total mass of the mixture of diethylene glycol bis(allyl carbonate) and oligomers of diethylene glycol bis(allyl carbonate).

[0031] L. The method according to any of items AK, wherein BPO and water account for 95% to 100%, in particular 99% to 100%, of the mass of the RIC.

[0032] M. The method according to item L, wherein water accounts for 5% to 40%, in particular 20% to 30%, of the mass of the free radical initiator composition (RIC).

[0033] N. A method according to any one of items AM, wherein the ratio m of the mass of water in the RIC to the dry mass of BPO in the free radical initiator composition 水1 / m BPO It is at least 0.28, specifically 0.29 to 0.45, more specifically 0.295 to 0.40, even more specifically 0.30 to 0.39.

[0034] O. The method according to any one of items AN, wherein steps a. to e. are carried out at room temperature.

[0035] P. The method according to any one of items AO, wherein the ratio m of the dry mass of BPO to the dry mass of the at least one allylic monomer or allylic oligomer is BPO / m 烯丙基 It is at least 0.01, specifically 0.014 to 0.046, more specifically 0.021 to 0.025, even more specifically 0.022 to 0.024.

[0036] Q. A method according to any one of items AP, wherein m 烯丙基 At least 95%, specifically 95% to 99%, more specifically 95% to 98%, even more specifically 95% to 97% of the total mass of the polymerizable composition.

[0037] R. A method according to any one of items AQ, wherein the mass m of the additive different from BPO, water and at least one allylic monomer or oligomer is 添加剂 It accounts for less than 1%, in particular less than 0.5%, of the total mass of the polymerizable composition.

[0038] S. The method according to any of items AR, wherein the polymerizable composition comprises at least one light absorbing additive, such as a dye, a pigment, a UV absorber, or an IR absorber.

[0039] T. The method according to item S, wherein the at least one light absorbing additive is mixed with the at least one allylic monomer or allylic oligomer and the free radical initiator composition during step c.

[0040] U. The method according to item S or item T, wherein the at least one light absorbing additive comprises a UV absorber soluble in the polymerizable composition, used alone or in a mixture with one or more color balancing dyes.

[0041] V. The method according to item U, wherein the UV absorber has the following structure (II):

[0042]

[0043] Where R 4 and R 5 are each independently selected from H or an alkyl chain having 1 to 12 carbon atoms, in particular wherein R 4 and R 5 It's methyl.

[0044] W. The method according to any of items SV, wherein the at least one light absorbing additive comprises from 0.02% to 0.5%, in particular from 0.05% to 0.2%, of the total mass of the polymerizable composition.

[0045] X. The method according to any one of items AW, wherein in step d., water is stripped from the polymerizable composition until the mass of water in the dried polymerizable composition is m 水2 Less than 0.65%, such as 0.05% to 0.65%, specifically less than 0.63%, such as 0.05% to 0.63%, more specifically less than 0.6%, such as 0.05% to 0.60%, even more specifically less than 0.59%, such as 0.05% to 0.59%, of the total mass of the dried polymerizable composition.

[0046] Y. A method according to any one of items AX, wherein curing the dried polymerizable composition comprises heating the dried polymerizable composition between 60°C and 125°C for 15 to 25 hours, wherein the heating comprises maintaining the dried polymerizable composition at a temperature of at least 110°C for 2 to 10 hours.

[0047] Z. The method according to any one of items AY, further comprising a step of annealing the lens after step f., the step of annealing the lens comprising or consisting of heating at a temperature of 85°C to 115°C for 45min to 1h30.

[0048] AA. The method according to any one of items AZ, further comprising a step of surface treatment of the lens, in particular of the back side of the lens, after step f. or, where applicable, after annealing.

[0049] BB. The method according to item AA, further comprising a step of applying a varnish after the surface treatment, which varnish improves the cosmetic resistance and / or scratch resistance of the lens.

[0050] CC. A method according to item BB, further comprising the step of applying an anti-reflective coating after applying the varnish.

[0051] DD. The method according to any one of items A to CC, further comprising a step of edging the lens after step f., preferably the step of edging the lens is performed directly after annealing the lens or together with the surface treatment.

[0052] EE. A method according to any one of items X to DD, wherein

[0053] In step d., water is stripped from the polymerizable composition until the mass of water in the dried polymerizable composition is m 水2 less than 0.6%, such as 0.05% to 0.60%, in particular less than 0.59%, such as 0.05% to 0.59%, of the total mass of the dried polymerizable composition,

[0054] The ratio m of the dry mass of BPO to the dry mass of at least one allylic monomer or allylic oligomer BPO / m 烯丙基 is 0.021 to 0.025, particularly 0.022 to 0.024,

[0055] m 烯丙基 at least 95% by weight of the total polymerizable composition,

[0056] The ratio of the mass of water in the RIC to the dry mass of BPO in the free radical initiator composition is m 水1 / m BPO It is at least 0.28, in particular 0.29 to 0.45.

[0057] FF. A polymerizable composition for making a lens, the polymerizable composition comprising at least one allylic monomer or oligomer, BPO and 0.05% to 0.65%, particularly 0.05% to 0.63%, more particularly 0.05% to 0.60%, even more particularly 0.05% to 0.59% water by mass relative to the total mass of the composition.

[0058] GG. The composition according to item FF, wherein the composition is a composition for the manufacture of an ophthalmic lens.

[0059] HH. The composition according to item FF or item GG, wherein the at least one allylic monomer or allylic oligomer is as defined in any one of items E to L.

[0060] II. A composition according to any one of items FF to HH, wherein the ratio m of the dry mass of BPO in the composition to the dry mass of at least one allylic monomer or allylic oligomer in the composition BPO / m 烯丙基 It is at least 0.01, specifically 0.014 to 0.046, more specifically 0.021 to 0.025, even more specifically 0.022 to 0.024.

[0061] JJ. A composition according to any one of items FF to II, wherein m 烯丙基 At least 95%, in particular 95% to 99%, more in particular 95% to 98%, even more in particular 95% to 97% of the total mass of the composition.

[0062] KK. A composition according to any one of FF-JJ, wherein the composition comprises at least one light absorbing additive, such as a dye, a pigment, a UV absorber, or an IR absorber.

[0063] LL. A composition according to item KK, wherein the at least one light absorbing additive comprises a UV absorber soluble in the composition, used alone or in a mixture with one or more color balancing dyes.

[0064] MM. A composition according to item LL, wherein the UV absorber has the following structure (II):

[0065]

[0066]

[0067] Where R 4 and R 5 are each independently selected from H or an alkyl chain having 1 to 12 carbon atoms, in particular wherein R 4 and R 5It's methyl.

[0068] NN. The composition according to any of items KK to MM, wherein the mass of the at least one light absorbing additive is from 0.02% to 0.5%, in particular from 0.05% to 0.2%, of the total mass of the composition.

[0069] OO. Use of less than 0.65%, such as 0.05% to 0.65%, particularly less than 0.63%, such as 0.05% to 0.63%, more particularly less than 0.60%, such as 0.05% to 0.60%, even more particularly less than 0.59%, such as 0.05% to 0.59% of water in a polymerizable composition comprising BPO and at least one allylic monomer or allylic oligomer for reducing the yellowness index of the cured polymerizable composition, wherein the percentage is a mass percentage relative to the total mass of the polymerizable composition.

[0070] PP. The use according to item OO, wherein the use is in the manufacture of lenses, in particular ophthalmic lenses.

[0071] QQ. The use according to item PP or item OO, wherein the at least one allylic monomer or allylic oligomer is as defined in any one of items E to L.

[0072] RR. The use according to any one of items OO-QQ, wherein the ratio m of the dry mass of BPO in the polymerizable composition to the dry mass of the at least one allylic monomer or allylic oligomer in the polymerizable composition BPO / m 烯丙基 It is at least 0.01, specifically 0.014 to 0.046, more specifically 0.021 to 0.025, even more specifically 0.022 to 0.024.

[0073] SS. Use according to any of items OO-RR, wherein the polymerizable composition comprises at least one light absorbing additive, such as a dye, a pigment, a UV absorber, or an IR absorber.

[0074] TT. The use according to item SS, wherein the at least one light absorbing additive comprises a UV absorber soluble in the polymerizable composition, used alone or in a mixture with one or more color balancing dyes.

[0075] UU. The use according to item TT, wherein the UV absorber has the following structure (II):

[0076]

[0077]

[0078] Where R4 and R 5 are each independently selected from H or an alkyl chain having 1 to 12 carbon atoms, in particular wherein R 4 and R 5 It's methyl.

[0079] VV. Use according to any of items SS to UU, wherein the at least one light absorbing additive represents from 0.02% to 0.5%, in particular from 0.05% to 0.2%, of the total mass of the polymerizable composition.

[0080] WW. The use according to any of items OO to VV, wherein the polymerizable composition is cured as in item T. DETAILED DESCRIPTION

[0081] The presently disclosed method for manufacturing a lens comprises the following steps:

[0082] a. Provide a certain quality m 烯丙基 at least one allylic monomer or allylic oligomer,

[0083] b. providing a free radical initiator composition comprising benzoyl peroxide (BPO) mixed with water,

[0084] c. mixing said at least one allylic monomer or allylic oligomer with the free radical initiator composition to obtain a polymerizable composition,

[0085] d. stripping water from the polymerizable composition to obtain a dried polymerizable composition,

[0086] e. providing a mold assembly and filling the mold assembly with the dried polymerizable composition,

[0087] f. curing the dried polymerizable composition in the mold assembly to obtain the lens.

[0088] In the methods disclosed herein, the lens can be an ophthalmic lens.

[0089] As defined herein, an ophthalmic lens is a lens designed to be used in a monocle or glasses (including sunglasses, goggles and safety glasses). As defined herein, contact lenses are not ophthalmic lenses. Ophthalmic lenses are typically used to protect the eyes and / or correct vision. Ophthalmic lenses can be non-corrective ophthalmic lenses (also known as plano or afocal lenses) or corrective ophthalmic lenses. Corrective lenses can be single-focus lenses, bifocal lenses, trifocal lenses or progressive lenses. As defined herein, ophthalmic lenses can be finished lenses or semi-finished lenses. Before being finally included in glasses or in a monocle, the semi-finished lenses undergo various processing steps, such as surface treatment, tinting, coating and edging. The finished lenses are ready to be included in glasses or in a monocle.

[0090] It should be understood that an allyl monomer or an allyl oligomer (hereinafter also referred to as an allyl component) can be a single allyl monomer, a single allyl oligomer, a mixture of two or more allyl monomers, a mixture of two or more allyl oligomers, or a mixture of one or more allyl monomers and one or more allyl oligomers.

[0091] The allyl component may be provided as part of an allyl composition comprising greater than 95%, specifically greater than 97%, more specifically greater than 99% by mass of allyl monomers or allyl oligomers relative to the total mass of the allyl composition.

[0092] The allyl composition may contain residual moisture, for example 0.003 to 0.04% by mass of water relative to the total mass of the allyl composition.

[0093] Where an allyl component is provided as part of an allyl composition, it is understood that 烯丙基 is the mass of the allylic component present in the allylic composition, thus excluding impurities such as water and other than allylic monomers or oligomers present in the allylic composition.

[0094] As defined herein, the at least one allylic monomer or allylic oligomer is a compound or mixture of compounds, wherein all of these compounds each contain at least two allyl groups.

[0095] In particular, in the methods disclosed herein, at least one allylic monomer or allylic oligomer may comprise 烯丙基At least 90%, more particularly 95% to 99%, by mass, of a compound selected from the group consisting of diethylene glycol bis(allyl carbonate), oligomers of diethylene glycol bis(allyl carbonate), ethylene glycol bis(allyl carbonate), oligomers of ethylene glycol bis(allyl carbonate), bisphenol A bis(allyl carbonate), oligomers of bisphenol A bis(allyl carbonate), diallyl phthalate, diallyl isophthalate, diallyl terephthalate and mixtures thereof.

[0096] It is understood that in oligomers of diethylene glycol bis(allyl carbonate), ethylene glycol bis(allyl carbonate), or bisphenol A bis(allyl carbonate), the repeating units are diethylene glycol carbonate units, ethylene glycol carbonate units, or bisphenol A carbonate units, respectively.

[0097] In the methods disclosed herein, the at least one allylic monomer or allylic oligomer may comprise 烯丙基 1 to 10%, specifically 1 to 5% by mass of a monomer represented by formula (I):

[0098]

[0099] Where R 2 is a polyvalent linking group without a carbamate bond; R 3 is a residue of a substance having a single hydroxyl group and at least one allyl group, R does not contain a urethane bond, and j is a number from 2 to 4.

[0100] Monomers of formula (I) are described in US 2003 / 0173551 A1.

[0101] For example, R 2 It may be a residue of an alicyclic diisocyanate selected from the group consisting of isophorone diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, bis(isocyanatomethyl)cyclohexane, bis(isocyanatocyclohexyl)methane, bis(isocyanatocyclohexyl)-2,2-propane, bis(isocyanatocyclohexyl)-1,2-ethane and mixtures thereof, and j is 2.

[0102] For example, R 3 It may be a residue selected from the group consisting of C2-C4 alkylene glycol allyl ether, poly(C2-C4 alkylene glycol) allyl ether (such as a residue selected from poly(ethylene glycol) allyl ether, poly(1,2-propylene glycol) allyl ether and mixtures thereof), trimethylolpropane di(allyl ether), trimethylolethane di(allyl ether), pentaerythritol tri(allyl ether), di-trimethylolpropane tri(allyl ether) and mixtures thereof.

[0103] The monomers of formula (I) may be included in the allyl component in order to prevent the formation of so-called "fern" defects observable on tinted lenses.

[0104] An example of a monomer according to formula (I) is CR39-E supplied by PPG Company (PPG).

[0105] In the methods disclosed herein, the at least one allylic monomer or allylic oligomer may comprise 烯丙基 95 to 99% by mass of a mixture of diethylene glycol bis(allyl carbonate) and oligomers of diethylene glycol bis(allyl carbonate), and relative to m 烯丙基 1 to 5% by mass of monomers of formula (I).

[0106] In particular, in this case, diethylene glycol bis(allyl carbonate) may account for 90% to 99% of the total mass of the mixture of diethylene glycol bis(allyl carbonate) and the oligomer of diethylene glycol bis(allyl carbonate).

[0107] In the method disclosed herein, BPO and water can account for 95% to 100%, particularly 99% to 100% of the mass of the free radical initiator composition (RIC). In this case, water can account for 5% to 40%, particularly 20% to 30% of the mass of the free radical initiator composition (RIC).

[0108] In the method disclosed herein, a sufficiently large ratio m of the mass of water in the RIC to the dry mass of BPO in the RIC is used. 水1 / m BPO The RIC of the present invention has a value of 1.5, which allows safe handling of BPO, in particular without requiring the use of low temperatures throughout the process. In fact, it is understood that no water is removed from the RIC before step c., for example before step d. Moreover, after step c., the BPO is in a mixture with the allyl component, which also makes it less hazardous (less sensitive to shocks and friction).

[0109] While large amounts of water in the RIC provide safety when handling BPO, excessive amounts are not practical because the water must be removed from the composition later in the process.

[0110] In the method disclosed herein, the ratio m of the mass of water in the RIC to the dry mass of BPO in the free radical initiator composition is 水1 / m BPO It may be at least 0.28, specifically 0.29 to 0.45, more specifically 0.295 to 0.40, even more specifically 0.30 to 0.39.

[0111] It should be understood that RIC is directly mixed in step c. to obtain the polymerizable composition. As discussed above, no step of removing water is performed between step b. and step c., such as no step of removing water is performed between step b. and step d., thus allowing safer and simpler handling of various compositions (e.g., RIC, polymerizable composition, dried polymerizable composition) when manufacturing lenses. In particular, various compositions can be safely handled at room temperature, and cryogenic temperatures do not need to be used.

[0112] In the methods disclosed herein, steps a. to e. can be performed at room temperature.

[0113] As defined herein, performing a step at room temperature means that no heating means or cooling means are used to bring the temperature of the compounds used in said step beyond the range of 15°C to 30°C.

[0114] In the methods disclosed herein, the ratio m of the dry mass of BPO to the dry mass of the at least one allylic monomer or allylic oligomer is BPO / m 烯丙基 may be at least 0.01, specifically 0.014 to 0.046, more specifically 0.021 to 0.025, even more specifically 0.022 to 0.024, and m 烯丙基 It may represent at least 95%, specifically 95% to 99%, more specifically 95% to 98%, even more specifically 95% to 97% of the total mass of the polymerizable composition.

[0115] Select the ratio m BPO / m 烯丙基 and the allyl ratio in the polymerizable composition to ensure proper polymerization of the allyl component in step f. For example, too low a ratio (insufficient amount of initiator) may result in insufficiently crosslinked polymer and thus poor thermomechanical properties of the lens.

[0116] Additives other than BPO, water and the allyl component may be present in the allyl composition or in the RIC prior to step c.

[0117] During step c., additives other than BPO, water and the allyl component may be mixed with the allyl component and the RIC.

[0118] If an additive is mixed with the allyl component and the RIC in step c., the additive may be mixed with the allyl component prior to mixing with the RIC.

[0119] The mass of additives m 添加剂(including additives other than BPO, water and the allyl component, which are initially present in the RIC or in the allyl composition or added in step c.) are included in the total mass of the polymerizable composition.

[0120] m 添加剂 It may represent less than 1%, in particular less than 0.5%, of the total mass of the polymerizable composition.

[0121] The additives may include light absorbing additives such as dyes, pigments, UV absorbers, or IR absorbers.

[0122] In the methods disclosed herein, at least one light absorbing additive may be mixed with at least one allylic monomer or allylic oligomer and the free radical initiator composition during step c.

[0123] The at least one light absorbing additive can include a UV absorber soluble in the polymerizable composition, used alone or in a mixture with one or more color balancing dyes.

[0124] The UV absorber may have the following structure (II):

[0125]

[0126] Where R 4 and R 5 are each independently selected from H or an alkyl chain having 1 to 12 carbon atoms, in particular wherein R 4 and R 5 It's methyl.

[0127] In the methods disclosed herein, the at least one light absorbing additive can account for less than 0.5%, specifically less than 0.2%, of the total mass of the polymerizable composition.

[0128] Surprisingly, it has been observed that when water is stripped from the polymerizable composition, lenses obtained from the thus dried polymerizable composition have a reduced yellowness index.

[0129] In the methods disclosed herein, in step d., water may be stripped from the polymerizable composition until the mass of water in the dried polymerizable composition is m 水2 Less than 0.65%, such as 0.05% to 0.65%, specifically less than 0.63%, such as 0.05% to 0.63%, more specifically less than 0.60%, such as 0.05% to 0.60%, even more specifically less than 0.59%, such as 0.05% to 0.59%, of the total mass of the dried polymerizable composition.

[0130] The means used to strip water from the polymerizable composition in step d. are not particularly limited. Any method known to the skilled person may be used.

[0131] It is clear that m 水2 represents the total mass of water in the dried polymerizable composition. Prior to stripping, the polymerizable composition may contain water, the water coming from m 水1 and from the water present in the allyl composition or in additives, if any.

[0132] It is clear that step d. is completed after the mixing step c. and before the curing step f. In particular, this step can be performed before step e. of filling the mold assembly.

[0133] It is also clear that no addition of water to the polymerizable composition occurs between step d. and curing step f.

[0134] Including m 水2 The water content in the mixture can be measured using a coulometric titration method known as the Karl Fischer coulometric method. This method is well known to the skilled person. An automated Karl Fischer titrator can be used for the titration.

[0135] The curing of the dried polymerizable composition includes free radical polymerization and crosslinking of the allylic component initiated by the free radical initiator BPO. This includes decomposing the BPO into free radical species that can initiate the reaction of the allylic component. This also includes the expansion of the polymerization reaction. The fragmentation of the BPO can be obtained by heating the composition, for example, by placing the filled mold assembly in an oven. Further heating can ensure sufficient expansion and crosslinking.

[0136] In the methods disclosed herein, curing the dried polymerizable composition can include heating the dried polymerizable composition between 60°C and 125°C for 15 to 25 hours, wherein the heating includes maintaining the dried polymerizable composition at a temperature of at least 110°C for 2 to 10 hours.

[0137] The method disclosed herein may further include a post-curing treatment. The post-curing treatment may include:

[0138] - Annealing the lens. Annealing helps to relieve internal stresses that may have built up in the lens during the previous steps of the method, in particular during the curing step. Annealing may comprise or consist of heating at a temperature of 85°C to 115°C for 45min to 1h30.

[0139] - In the case of corrective ophthalmic lenses, surface treatments of the lenses, in particular of the back side of the lens, ie the side of the lens closest to the wearer's eye. Surface treatments help adjust the geometry of the lens to give the lens the desired corrective power.

[0140] - Application of a varnish which improves the cosmetic resistance and / or scratch resistance of the lenses.

[0141] - Apply an anti-reflective coating.

[0142] -Polished lenses.

[0143] -Edge the lenses.

[0144] The present disclosure also relates to a polymerizable composition for the manufacture of lenses, particularly ophthalmic lenses (hereinafter the presently disclosed composition), comprising at least one allylic monomer or oligomer, BPO and 0.05% to 0.65%, particularly 0.05% to 0.63%, more particularly 0.05% to 0.60%, even more particularly 0.05% to 0.59% water by mass relative to the total mass of the composition.

[0145] What has been said with respect to the allyl component with respect to the methods disclosed herein applies mutatis mutandis to the at least one allylic monomer or allylic oligomer in the presently disclosed compositions.

[0146] As for the presently disclosed methods, for the polymerizable compositions of the disclosed compositions, the ratio m can be defined mutatis mutandis. BPO / m 烯丙基 .

[0147] Regarding the method disclosed in this article, 烯丙基 And about the ratio m BPO / m 烯丙基 The contents described apply mutatis mutandis to the presently disclosed compositions. 烯丙基 and ratio m BPO / m 烯丙基 .

[0148] The presently disclosed composition may contain additives. The mass m of the additive in the presently disclosed composition 添加剂 It may account for less than 1%, in particular less than 0.5% of the total mass of the presently disclosed composition.

[0149] What has been said with respect to additives with respect to the methods disclosed herein applies mutatis mutandis to the additives of the presently disclosed compositions.

[0150] When the presently disclosed composition includes light absorbing additives, these light absorbing additives may account for 0.02% to 0.5%, specifically 0.05% to 0.2% of the total mass of the presently disclosed composition.

[0151] The present disclosure also relates to the use of less than 0.65%, such as 0.05% to 0.65%, specifically less than 0.63%, such as 0.05% to 0.63%, more specifically less than 0.6%, such as 0.05% to 0.60%, even more specifically less than 0.59%, such as 0.05% to 0.59%, of water in a polymerizable composition comprising BPO and at least one allylic monomer or allylic oligomer for reducing the yellowness index of the cured polymerizable composition, wherein the percentage is a mass percentage relative to the total mass of the polymerizable composition.

[0152] In particular, the presently disclosed use may be use in the manufacture of lenses, in particular ophthalmic lenses.

[0153] What has been said with respect to the allyl component with respect to the methods disclosed herein applies mutatis mutandis to the at least one allylic monomer or allylic oligomer of the presently disclosed uses.

[0154] As for the presently disclosed methods, the ratio m can be defined for the polymerizable compositions of the presently disclosed uses: BPO / m 烯丙基 .

[0155] Regarding the method disclosed herein, 烯丙基 And about the ratio m BPO / m 烯丙基 The contents described are applicable to the purposes currently disclosed mutatis mutandis. 烯丙基 and ratio m BPO / m 烯 Propyl.

[0156] The polymerizable composition of the presently disclosed use may contain additives. The mass m of the additives in the presently disclosed use 添加剂 It may represent less than 1%, in particular less than 0.5%, of the total mass of the polymerizable composition.

[0157] What has been said about the additives with respect to the methods disclosed herein applies mutatis mutandis to the additives for the presently disclosed uses.

[0158] In the presently disclosed uses, when the polymerizable composition comprises light absorbing additives, the light absorbing additives may account for 0.02% to 0.5%, specifically 0.05% to 0.2% of the total mass of the polymerizable composition.

[0159] What has been said about curing with respect to the methods disclosed herein applies mutatis mutandis to curing for the presently disclosed uses.

[0160] Examples

[0161] Titration of water

[0162] The water content in the samples was measured by Karl Fischer coulometric titration using an automated Karl Fischer titrator (Metrohm-870KFtitrino plus).

[0163] Measurement of Yellowness Index (YI)

[0164] The yellowness index of the lens was measured according to ASTM E313 standard using a CARY60 spectrometer on a 2 mm thick plano lens.

[0165] Lens preparation

[0166] A 2 mm thick plano lens was produced according to the following procedure.

[0167] Table 1 Composition of polymerizable composition for preparing lenses

[0168] Components % by mass Function state CAS Chiguard BP-6 0.11 UV absorbers solid 131-54-4 CR39-E 2.00 additive liquid dedicated BPO 75% 3.00 peroxide solid 94-36-0 CR-39 94.89 monomer liquid 142-22-3

[0169] In Table 1, Chiguard BP-6 is the following molecule:

[0170]

[0171] In Table 1, CR39 indicates a commercial product sold by PPG Industries, Inc. It is a composition comprising more than 98% by mass of a mixture of diethylene glycol bis(allyl carbonate) and oligomers of diethylene glycol bis(allyl carbonate) relative to the total mass of the composition. In CR39, diethylene glycol bis(allyl carbonate) accounts for more than 91% of the total mass of the mixture of diethylene glycol bis(allyl carbonate) and oligomers of diethylene glycol bis(allyl carbonate).

[0172] In Table 1, "BPO 75%" means a mixture of BPO and water in the form of particles containing 75% by mass of BPO and 25% by mass of water relative to the total mass of the mixture.

[0173] The procedure is as follows:

[0174] 1) Mix CR39, CR39-E and Chiguard BP-6 at room temperature for 1 hour until the UV absorber is completely dissolved.

[0175] 2) Add BPO 75% at room temperature and stir the mixture until all BPO is dissolved.

[0176] 3) Strip water from the mixture using a rotary evaporator at room temperature and low stirring speed.

[0177] 4) At this point, the water content of the mixture was measured using Karl Fischer coulometric titration.

[0178] 5) Fill the mold assembly lined with standard material with the mixture.

[0179] 6) Allow the mixture to solidify.

[0180] Four experiments were performed in which the only parameter varied was the evaporation time of water at step 3) in the above procedure, where the times were 0, 30, 60 and 90 min (comparative experiments BPO-1 and BPO-2 and experiments according to the present disclosure BPO-3 and BPO-4).

[0181] Comparative experiments using IPP instead of BPO were performed, wherein the amount of water was controlled by adding increasing amounts of water to the mixture (experiments IPP-1, IPP-2, IPP-3, IPP-4 and IPP-5).

[0182] result

[0183] The results are presented in Table 2.

[0184] Table 2

[0185]

[0186]

[0187] It can be seen that the effect of water content on the yellowness index is specific to BPO, as no effect was observed with IPP.

Claims

1. A method for manufacturing a lens, the method comprising the following steps: a. Provide a certain quality m 烯丙基 at least one allylic monomer or allylic oligomer, b. providing a free radical initiator composition, the free radical initiator composition comprising benzoyl peroxide (BPO) mixed with water, c. mixing the at least one allylic monomer or allylic oligomer with the free radical initiator composition to obtain a polymerizable composition, d. stripping water from the polymerizable composition to obtain a dried polymerizable composition, e. providing a mold assembly and filling the mold assembly with the dried polymerizable composition, f. curing the dried polymerizable composition in the mold assembly to obtain the lens.

2. The method according to claim 1, wherein: The ratio m of the mass of the water in the free radical initiator composition to the dry mass of the BPO in the free radical initiator composition 水1 / m BPO It is at least 0.

28.

3. The method according to claim 1 or 2, wherein: The ratio m of the dry mass of the BPO to the dry mass of the at least one allyl monomer or allyl oligomer BPO / m 烯丙基 is at least 0.014 to 0.046, and wherein m 烯丙基 The polymerizable composition comprises at least 95% by weight of the total polymerizable composition.

4. The method according to any one of claims 1 to 3, wherein: In step d., water is stripped from the polymerizable composition until the mass of water in the dried polymerizable composition is m 水2 Less than 0.65% of the total mass of the dried polymerizable composition.

5. The method according to any one of claims 1 to 4, wherein: The lens is an ophthalmic lens.

6. The method according to any one of claims 1 to 5, wherein: The at least one allylic monomer or allylic oligomer is a compound or mixture of compounds, wherein all of the compounds each contain at least two allyl groups.

7. The method according to any one of claims 1 to 6, wherein: The at least one allylic monomer or allylic oligomer comprises 烯丙基 At least 90% by mass of the compound selected from the group consisting of diethylene glycol bis(allyl carbonate), oligomers of diethylene glycol bis(allyl carbonate), ethylene glycol bis(allyl carbonate), oligomers of ethylene glycol bis(allyl carbonate), bisphenol A bis(allyl carbonate), oligomers of bisphenol A bis(allyl carbonate), diallyl phthalate, diallyl isophthalate, diallyl terephthalate and mixtures thereof.

8. The method according to claim 7, wherein: The at least one allylic monomer or allylic oligomer comprises 烯丙基 % by mass 1% to 10% of a monomer represented by formula (I): Where R 2 is a polyvalent linking group without a carbamate bond; R 3 is a residue of a substance having a single hydroxyl group and at least one allyl group, R does not contain a urethane bond, and j is a number from 2 to 4.

9. The method according to claim 8, wherein: The at least one allylic monomer or allylic oligomer comprises 烯丙基 95 to 99% by mass of a mixture of diethylene glycol bis(allyl carbonate) and oligomers of diethylene glycol bis(allyl carbonate), and containing about 1% by mass of diethylene glycol bis(allyl carbonate) relative to m 烯丙基 1 to 5% by mass of monomers of formula (I).

10. The method according to any one of claims 1 to 9, wherein: Steps a. to e. are carried out at room temperature.

11. The method according to any one of claims 1 to 10, wherein: At least one light absorbing additive is mixed with the at least one allylic monomer or allylic oligomer and the free radical initiator composition during step c.

12. The method according to claim 11, wherein: The at least one light absorbing additive comprises less than 0.5% of the total mass of the polymerizable composition.

13. The method according to any one of claims 1 to 12, wherein: Curing the dried polymerizable composition includes heating the dried polymerizable composition between 60° C. and 125° C. for 15 to 25 hours, the heating including maintaining the dried polymerizable composition at a temperature of at least 110° C. for 2 to 10 hours.

14. A polymerizable composition for producing a lens, comprising at least one allylic monomer or oligomer, BPO and 0.05% to 0.65% by mass of water relative to the total mass of the composition.

15. Use of less than 0.65% of water in a polymerizable composition comprising BPO and at least one allylic monomer or allylic oligomer for reducing the yellowness index of the cured polymerizable composition, wherein the percentage is a mass percentage relative to the total mass of the polymerizable composition.

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