FR2762845A1 - Radically polymerisable composition - Google Patents

Abstract

Radically polymerisable compsn. comprising a mixt. of (a) 40-99 pts.wt. difunctional monomer (s) of type (a) from monomers of formula (A); and (b) 1-60 pts.wt. difunctional monomer (s) of type (b) from long chain alkenic difunctional oligomers of formula (B).Also claimed are:(1) a resin; and( 2) ophthalmic article. In (A), R1, R'1, R and R' = H or methyl; m and n = integers 0-4; X and X' = halogen; p and q = integers 0-4. In (A') R1 and R'1 = H or methyl; R = linear or branched 2-8C alkyl, 3-6C cycloalkyl, ether radical of formula (R'-O-R''); R' and R'' = linear or branched 2-4C alkyl. In (B), R1, R'1, R2 and R'2, = H or linear or branched 1-4C alkyl; R3, R4, R'3 and R'4 = H and 2-6C alkenyl and are different; Z and Z' = (thio)carbamate or urea and are different; R' = linear or branched 2-4C alkyl; R = identical or different when n at least 2, is a linear or branched 2-4C alkyl; Y = when n at least 2, is O or S; n = integer such that the total number of C atoms contained in the long chain situated between Z and Z' is at least 18; In (B'), n = integer such that the total number of C atoms contained in the long chain of (R-Y)n is 22 or greater; In (B''), Z' = (thio)carbamate; n = integer such that the total number of C atoms contained in the long chain of (R-Y)n-R' is 22 or greater

Description

The subject of the present invention is: a polymerizable composition

  radical route, based on at least two different types of difunctional monomers; a resin obtained by copolymerization of said composition; said resin having a nanobiphasic structure and may or may not be photochromic; - articles, particularly ophthalmic, made in whole or in part of

said resin.

  The production of a plastic ophthalmic lens is a difficult exercise insofar as it is required that the structure of said lens be free from optical constraints and obviously has satisfactory mechanical properties. To achieve this result, it is necessary to perfectly control the copolymerization reactions involved in the development of said lens. In any case, it is necessary to avoid reaching the freezing point of the reaction system too quickly, since, in the case of "local over-treatments", strings or other optical defects inevitably appear. This problem is a real problem since the basic monomers known to date are

  generally symmetrical difunctional monomers ...

  Moreover, in the context of the production of photochromic ophthalmic lenses, either by radical polymerization of compositions containing at least one photochromic dye, or by subsequent diffusion of such dyes in polymerized matrices, the structure of said lenses should, in addition to the optical qualities recalled above, a pronounced ability to promote the expression of the photochromic properties of said photochromic dyes that intervene; this without any notable alteration of its mechanical properties. Achieving an acceptable compromise - photochromic properties / mechanical properties - is not easy. It is intended to prepare a nanobiphase structure - to avoid light scattering phenomena, which are detrimental to obtaining good optical quality - which has a phase ensuring the mechanical rigidity of said structure and another phase conferring on said structure sufficient flexibility to allow the photochromic dye (s) incorporated within it to express quickly and at best their photochromic properties. To the knowledge of the Applicant, according to the prior art, within the framework of such a compromise, no satisfactory compositions have been prepared (both from the point of view of expression of photochromism and from the point of view of absence of constraints). It has been proposed in EP-A-0 453 149 and WO-A-95 10790 to copolymerize two types of monomers, both of which, however, have the same type of reactive functions (acrylate and / or methacrylate groups). . The result is not very satisfactory in terms of optical properties and ease of casting. It has been proposed in US Pat. No. 5,349,035 to minimize or even avoid optical stresses, to associate with a dimethacrylate monomer, at least one other monomer, in particular styrene, and to carry out the copolymerization in the presence of an effective amount of a chain transfer agent. The matrix obtained is not suitable for expressing the properties

  photochromic photochromic dyes.

  EP-A-0 345 748 and EP-A-0 351 534 disclose difunctional monomers (having terminal isopropenyl functionality) suitable for the preparation of transparent hard resins. EP-A-0 385 456 and EP-A-0 572 077 also describe short-chain multifunctional monomers and their copolymerization with other functionalized monomers (acrylate, methacrylate, and / or styrene) to prepare resins, transparent, with high surface hardness. Said hard resins, according to these four European patent applications, are oriented towards non-photochromic ophthalmic applications. Said monomers are obtained from compounds of formula: CH2

HC C H3

3 1? "

C -N = C = O

CH3

known as TMI.

  There is also an abundant literature on the chemistry of said compounds and in particular on that of 3-isopropenyl-α, α-dimethylbenzyl isocyanate (compound of the formula above with the two substituents in meta, known under the name m-TMI). . This chemistry is based on the reactivity of the isocyanate group. The following documents can be cited: + Cellular Polymers, 4, (1985), p. 117-149 by R. Saxon et al .: in this document, it is mentioned the two possibilities of reaction of the TMIV, either by its isocyanate function, or by its isopropenyl function; + Journal of Coatings Technology, Vol. 58, No. 737, p. 43-47, 1986 by R.W. Dexter et al .: This document describes the reaction of TMI with a diol and, in general, the possibility of copolymerizing the obtained monomer with acrylic derivatives; + Polymer Communications, 1990, Vol. 31, p. 355-357 by D. Wilson et al. In this document, the synthesis and characterization of graft copolymers of polyurethane-poly (methylmethacrylate) type, obtained using TMI; US-A-4,990,575: in this patent, it is described the preparation of ureas of a

  new type which are obtained by reacting polyoxyalkyleneamines with the m-

TMI.

  The teaching of these documents remains very general.

  The Applicant is currently proposing an original solution to this technical problem of the compromise between the optical properties, or even photochromic properties, and the mechanical properties of a plastic material that can be used, particularly in ophthalmology. The invention implemented by the Applicant consists in associating, by radical copolymerization, at least one short-chain (meth) acrylic difunctional monomer with at least one long-chain alkenic difunctional monomer. The resulting resin then has a nanobiphasic structure giving it the desired properties. Indeed, said difunctional monomer (s) (meth) acrylic (s) short chain (type (a) and formula (A), (A '): see below) brings (nt) ) the stiffness, which is modulated by the presence of said long chain (type b) and formula (B) difunctional (s) monomer (s), (B '), ( B "): see below), which (s), in a surprising way, also makes it possible to confer on said composition excellent photochromic properties.Thus, the difference in functionality of said monomers of the type (a) and (b) advantageously delays the setting of the resultant polymerizable composition in gel.This characteristic enables the resin obtained from said composition to exhale good optical properties and especially in the case where photochromic dyes are incorporated within it,

  to express quickly and at best the photochromic properties.

  The present invention therefore has as its first object a radically polymerizable composition; said composition comprising a mixture of at least one or more difunctional monomers of type (a) and one or more difunctional monomers of type (b): the monomer (s) difunctional (s) of type (a) (meth) acrylic - corresponding to one or the other of formulas (A) and (A ') below: + formula (A): CH 3 H 2 C = CC (OCHR-CH 2) m - (CH 2 -CH 2 O ) in which: R1, R'1, R and R ', which may be identical or different, are independently a hydrogen or a methyl group; m and n are, independently, integers between 0 and 4 inclusive; and are advantageously independently equal to 1 or 2; X and X ', which may be identical or different, are halogen and preferably represent chlorine and / or bromine; p and q are, independently, integers between 0 and 4 inclusive; + formula (A '):

GOLD'

He 1

H2C-C - (O-R) -O-C-CCH2

  Wherein: R1 and R'1, which may be identical or different, are independently a hydrogen or a methyl group; R is a linear or branched alkyl radical containing from 2 to 8 carbon atoms, a cycloalkyl radical containing from 3 to 6 carbon atoms, an ether radical of formula (R'-OR ") in which R 'and R", identical or different, are independently a linear or branched alkyl radical having 2 to 4 carbon atoms; difunctional monomer (s) of the difunctional long-chain dienunctional oligomer type (b), which correspond to one or other of the formulas (B), (B ') and (B ") hereinafter: + formula (B): R 3

R R '

R4 C-Z- (R-Y) -R-Z 'V-R4

R2 R'2

  R = 3 in which: R1, R'1, R2 and R'2, which are identical or different, are independently hydrogen or a linear or branched, advantageously linear, alkyl radical containing from 1 to 4 carbon atoms; and correspond, in a particularly advantageous manner, to a methyl group; - R3 and R4, different, are independently hydrogen and the other an alkenyl radical having from 2 to 6 carbon atoms, preferably from 2 to 4 carbon atoms and particularly advantageously an isopropenyl radical; R'3 and R'4, which are different, are independently hydrogen and the other is an alkenyl radical containing from 2 to 6 carbon atoms, advantageously from 2 to 4 carbon atoms, and in a particularly advantageous manner an isopropenyl radical; (Advantageously, both ends of the molecule are identical: i.e: R3 = R'3 and R4 = R'4); Z represents a carbamoyl function (-NH-CO-O-), a thiocarbamate function (-NH-CO-S-) or a urea function (-NH-CO-NH-); Z ', independently of Z and advantageously respectively with respect to Z, represents a carbamoyl function (-O-CO-NH-), a thiocarbamate function (-S-CO-NH-) or a urea function (-NH- CO-NH-); - R 'represents a linear or branched alkyl radical having 2 to 4 carbon atoms; - R, identical or different when n> 2, is a linear or branched alkyl radical having 2 to 4 carbon atoms; Y, identical or different when n> 2, is oxygen or sulfur; n is an integer defined such that the total number of carbon atoms, contained in the long chain located between the two Z and Z 'units, is at least 18 and advantageously is between 18 and 18. and 112 included; + formula (B '):

R 0 O

IlI R4 C-N o - (R-Y) n R4

R2 R'2

R3

  in which - R1, R2, R3, R4, R'1, R'2, R'3, R'4, R and Y are as defined above with reference to formula (B); n is an integer defined such that the total number of carbon atoms contained in the long motif chain (RY) n is at least 22 and advantageously between 22 and 104 inclusive; ; + formula (B "):

R3 R3

R O R '

R4J C-N O- (R-Y) R 'Z'-Z C R'4

R2 R'2

  in which: R1, R2, R3, R4, R'1, R'2, R'3, R'4, R, R 'and Y are as defined above with reference to formula (B); Z 'is a carbamate function (-O-CO-NH-) or Z' is a thiocarbamate function (-S-CO-NH-); advantageously, Z 'is a carbamate function; n is an integer defined so that the total number of carbon atoms contained in the long motif chain (R-Y) n-R 'is at least 22 and

  advantageously between 22 and 104 inclusive.

  Said polymerizable composition is moreover likely to contain in addition: (c) at least one aromatic monovinyl monomer of formula (C) Ri

O CCH2

  wherein R1 = H or CH3; said monovinyl monomer preferably consisting of styrene and / or (d) at least one aromatic divinyl monomer of formula (D): o1

(C- = CH2) 2

  wherein R1 = H or CH3; said divinyl monomer preferably consisting of divinylbenzene; and / or (e) at least one (meth) acrylic monomer of formula (E)

CH2 = C (R) -COOR '

  in which R = H or CH3 and R 'is a linear or branched alkyl radical containing from 4 to 16 carbon atoms, an optionally substituted methylphenyl or methylphenoxy radical (generally with a C4-C6 alkyl group) or a polyoxyethoxylated group of formula - (CH2-CH2-O) nR "wherein n is an integer from 1 to 10 and R" = CH3 or C2H5; said

  (meth) acrylic monomer advantageously consisting of 2-ethylhexyl-

methacrylate; and or

(f) diallylphthalate.

  Said compositions of the invention generally contain, in addition, an effective amount of at least one radical polymerization initiator and an effective amount of at least one polymerization modifier, said modifier

  the polymerization is preferably a chain transfer agent.

  In the case where it is desired to impart photochromic properties to said polymerizable compositions of the invention (to the resins obtained by polymerization of said compositions), these contain an effective amount of at least one photochromic dye; said dye (s) being advantageously chosen from the group of spiroxazines, chromenes and mixtures thereof. The intervention of photochromic dyes of another type, such as

  spiropyrans, fulgids and others ...

  The natures and quantities of each of the components which are involved in or capable of intervening in the polymerizable compositions of the invention, and in particular in preferred compositions of the invention, are now examined in greater detail. The monomers of type (a) of formula (A) and (A ') constitute the

  monomers (meth) acrylates (i.e. diacrylates, dimethacrylates or mixed: acrylates-

  short-chain difunctional methacrylates) of the polymerizable composition of the invention. Said monomers have a more or less pronounced symmetry (R / R ', Ri / R'1, X / X'). They make it possible to confer the rigidity, and therefore the mechanical properties, on the polymer (resin) obtained from said

polymerizable composition.

  The monomers of type (a) may or may not all have the same formula (A) or (A '). Thus, the invention also includes polymerizable compositions comprising: either monomers of the same formula (A) ) (at least one); or monomers of the same formula (A ') (at least one); or mixtures (not mixed) of monomers of formulas (A) different; or mixtures (not mixed) of monomers of formulas (A ') different; or mixtures (mixed) of monomers of formula (s) (A) and

formula (s) (A ').

  According to a preferred variant of the invention, one or more symmetrical monomers of type (a) are used. These monomers of type (a), of formula (A) or (A ') in which the groups R1 and R'1 are identical, as well as the groups R and R' as well as the substituents X and X 'for compounds

of formula (A).

  Said monomers of type (a) of formula (A) symmetrical are known and commercially available or easily accessible to those skilled in the art. Indeed, it may be noted that said monomers not exhibiting halogen on the aromatic rings correspond to the first monomers of formula (I) in the sense of document WO-A-92/05209. Said monomers of type (a) of formula (A) having one or more halogen (s) on the aromatic ring (s) will be easily obtained by those skilled in the art by using derivatives suitably substituted on the so-called aromatic cycle (s). In the context of the invention, the monomers of formula (A), in which R and R ', which are identical, are hydrogen or a methyl group, R1 and R'1 are a methyl group, m and n are independently equal to one another. I or 2, and p = q = 0, are preferred. A particularly advantageous variant

  corresponds to the monomer of formula (A) of the above type, with R = R '-

  H and m = n = 2. Said monomer is in particular marketed by the company AKZO NOBEL (NL) under the trade name DIACRYL 121. The synthesis of the monomers of formula (A) asymmetric do not pose any problems

particular to the skilled person.

  The monomers (a) of formula (A ') are also well known and result from the conventional reaction of an aliphatic diol or a short chain alkylene glycol (with a maximum of 8 carbon atoms in said chain) with at least a type of (meth) acrylic derivative depending on whether it is desired to obtain

  monomers of formula (A ') symmetrical or asymmetrical at their ends.

  These monomers of type (a) are generally involved in the composition to be polymerized, in a proportion of 40 to 99 parts by weight per 100 parts by weight of the monomer mixture of types (a) and (b). If they occur in smaller amounts, the polymerizable composition tends to shrink during its polymerization, which induces premature demolding, which in turn is

  responsible for a deterioration of the optical properties of the final resin.

  The monomers (b) of formula (B), (B ') and (B ") constitute the long-chain difunctional alkenic monomers of the polymerizable composition of the invention, said monomers having a symmetry or not.

  more or less pronounced (RI / R'1, R2 / R'2, R3 / R'3, R4 / R'4, Z / Z ').

  These monomers of type (b) may or may not all have the same formula (B), (B ') or (B "). Thus, the invention also comprises polymerizable compositions comprising: either monomers of the same formula (B) (at least one) - either monomers of the same formula (B ') (at least one) - or monomers of the same formula (B ") (at least one); or mixtures (not mixed) of monomers of formulas (B) different; or mixtures (not mixed) of monomers of formulas (B ') different; or mixtures (not mixed) of monomers of different formulas (B "); or mixtures (mixed, binary or ternary) of selected monomers

  among the monomers of formula (s) (B), of formula (s) (B ') and of formula (s) (B ").

  The presence in the polymerizable composition of the invention of monomer (s) of type (b) allows a softening of the polymer network by releasing said network, without reducing the degree of crosslinking of the polymer. This makes it possible to impart to the material interesting mechanical properties at high temperature, characterized, in particular, by a value of

  high modulus of elasticity to the rubber tray of the polymer.

  The monomers of type (b) which are long-chain alkenic difunctional oligomers, said chain being a polyoxyalkylene or polymercaptoalkylene chain or even a mixed chain, are obtained according to conventional conditions of organic synthesis by reaction: - between one or more derivatives having a Alkenylisocyanate type functionality, of formula I and / or II:

R3 R'3

  R 1 R 4 C-CN = CO and / or R '4 C -N = C = OR 2 R 1' 2 formula I formula II in which R 1, R 2, R 3, R 4, R '1, R' 2, R'3 and R'4 are as defined above. According to a preferred variant of the invention, the monomers of type (b) used are symmetrical at their ends. For this purpose, only one type of alkenyl isocyanate derivative is used (thus formulas I and II are identical). In a particularly advantageous manner, a vinylisocyanate derivative is used, in which R 1 = R 2 = CH 3 (or R '1 = R' 2 = CH 3), R 3 (or R '3) is an isopropenyl radical and R 4

  (or R'4) is hydrogen, corresponding to said 3-isopropenyl-a, ta-

  dimethylbenzyl isocyanate (general name m-TMI defined above). Oligomers (b) obtained from said derivatives are preferred; and a compound intrinsically having a long chain, said compound being: a compound which is symmetrical at its terminal functions corresponding to: + a diol of formula HO- (R-Y) n -R'-OH; + or a dithiol of formula HS- (R-Y) n-R'-SH; + or a diamine of formula H 2 N- (R-Y) n -R'-NH 2; allowing then to obtain said oligomers of formula (B) intrinsically symmetrical (by intrinsically symmetric means monomers of formula (B) in which groups Z and Z 'are functions of identical nature); + or a biepoxy of formula CH-CH-O- (R-Y) n-CH-CH

O O

  the reaction then leading to the synthesis of said oligomers of formula (B '); * is a compound asymmetrical at its terminal functions: + said functions may be an alcohol function, thiol or amine; all the combinations being possible: these compounds making it possible to obtain other difunctional oligomers of formula (B) that are intrinsically asymymetric (by "intrinsically unsymmetrical" is meant monomers of formula (B) in which the groups Z and Z 'are functions of nature different); + said functions being respectively an epoxy function and an alcohol function or an epoxy function and a thiol function, the compounds then being of the formula CH ## STR2 ## or (SH) ,

  the reaction then leading to the synthesis of said oligomers of formula (B ").

  In all cases, R, R ', Y and n are as defined above; in a preferential manner Y is oxygen (the long chain then being a polyoxyalkylene chain). The molecular mass of the polyoxyalkylene and / or polymercaptoalkylene long chain, corresponding to the radical (RY) nR 'or (RY) n in said formulas (B, B', B ") specified above, is generally at least 500 g.mol'1 and less than 2000 g.mol-1, and preferably, said mass

  Molecular weight is between 600 g / mol and 900 g / mol.

  In a particularly advantageous manner, one or more monomers of type (b) of formula (B) intrinsically symmetrical (as defined above) are used: R 3 R '

11 R'1

R4 C -Z- (R-Y) R'-Z'-C R.

4I nI

R2 R'2

  Wherein R, R ', R1, R2, R3, R4, R'1, R'2, R'3, R'4 are as defined above (and advantageously such that both ends of the molecule are identical; ie: R, = R'1, R2 = R'2, R3 = R'3 and R4 = R'4, with even more advantageously R = R ', = R2 = R'2 = CH3 and R3 = R'3 and R4 = R'4 with one of R3, R4 being hydrogen and the other being an isopropenyl group) and Y is as defined above and advantageously consists of an oxygen (X = 0) and: (ca) - Z and Z 'are carbamate functions of the respective formulas (-NH-CO-O-) and (-O-CO-NH-); n is an integer defined so that the total number of carbon atoms contained in the long chain between the two Z and Z 'units is between 18 and 112; and advantageously between 24 and 112 in the case of a polyoxyalkylene chain and particularly advantageously between 26 and 50 in the case of a polyoxyalkylene chain with a molecular mass of between 600 and 900 g / mol-1; or (3) - Z and Z 'are thiocarbamate functions of the respective formula (-NH-CO-S-) and (-S-CO-NH-) - n is an integer defined so that the total number of carbon atoms, contained in the long chain between the two Z and Z 'units, being between 18 and 108; and advantageously between 24 and 108 in the case of a polyoxyalkylene chain and particularly advantageously between 28 and 46 in the case of a polyoxyalkylene chain with a molecular mass of between 600 and 900 g / mol; or (y) - Z and Z 'are urea functions (-NH-CO-NH-) - n is an integer defined such that the total number of carbon atoms contained in the long chain lying between the two Z and Z 'motifs, being between 18 and 112; and advantageously between 24 and 112 in the case of a polyoxyalkylene chain and particularly advantageously between 28 and 50 in the case of a polyoxyalkylene chain of

  molecular weight between 600 and 900 g.mo1-1.

  The person skilled in the art will have understood that formula (B), in the case (a) above,

  above o the number of carbon atoms, contained in the long chain is equal to 50, can for example be written:

R3 R

R 0 0R

  C-N-NH C ((CCl) 4O) 1r-j (Cl 2) 2 NHC 4

R2 R2

  Similarly, one skilled in the art will have understood that in general terms the minimum values mentioned above, defining the number of carbon in the long chain of (R-Y) n-R 'or (R-Y) n, correspond to

  compounds having a polymercaptoalkylene chain (Y = S).

  In a particularly advantageous manner, the said monomer (s) of type (b) have a general formula (B), as described above, and in which: R 1, R 2, R '1 and R 2, identical, are methyl radicals; R3 and R'3 are isopropenyl radical; R4 and R'4 are hydrogen and + or Z and Z 'are urea functions (-NH-CO-NH-) and - R' represents an ethylene or propylene group; n is an integer equal to 13 or 19 defining a total number of carbon atoms, between Z and Z ', equal to 28 or 40 when (R-Y) n is a polyoxyethylene chain; or n is an integer equal to 10 or 14 defining a total number of carbon atoms, between Z and Z ', equal to 33 or 45 when (R-Y) n is a polyoxypropylene chain; or n is an integer between the lower (10-13) and upper (14-19) limit values as defined above, when (R-Y) n is a polyoxyethylene / polyoxypropylene mixed chain; defining then the monomers of type (b) denomination RUDI JEF 600 and RUDI JEF 900 (see further in the examples), respectively when na one of the lower limit values (n between 10 and 13 inclusive) and na the one of the upper limit values (n between 14 and 19 inclusive); + and Z 'and Z' are carbamate functions of the respective formulas (-NH-CO-O-) and (-O-CO-NH-) and - R 'represents an ethylene group; - (R-Y) n represents a long polyoxyethylene chain; n is an integer equal to 13 or 19 defining a total number of carbon atoms, contained in the long chain located between the two Z and Z 'units, equal to 28 or; defining then the type (b) monomers RUDI 600 and RUDI 900 (see further in the examples), respectively when n = 13 and n = 19. The monomers of type (b) are generally involved in the composition to be polymerized, in a proportion of 1 to 60 parts by weight per 100 parts by weight.

  weight of the monomer mixture of (a) and (b).

  The polymerizable composition of the invention may also contain, as already indicated, other monomers. In general, for 100 parts by weight of the monomer mixture of types (a) and (b), said composition may contain from 1 to 60 parts by weight (advantageously from 10 to 50 parts by weight) of at least one monomer , chosen from alkenic monomers (such as those of formulas (C) and (D) and diallyl phthalate (f)), advantageously vinyl and allylic, (meth) acrylic monomers (such as those of formula (E)) and their mixtures. In view of the desired effects, when these types of monomers are added, those skilled in the art will be able to determine and optimize the intervening quantities of each type of said monomers (in any case, the total amount of said monomer (s)) (s) involved in the polymerizable composition is between I to 60 parts by weight of the mixture of monomers of type (a) and (b)). The vinyl monomers of formula (C), styrene and / or methylstyrene, are used in combination with the monomer (s) of type (a) to relax the network. Intervention at this level of styrene may be particularly advantageous in that this polymerized compound has a fairly high refractive index (n = 1.595). Said styrene is the particularly preferred compound of this class of monomer.

  The compound of formula (D) is divinylbenzene (DVB) or di (methylvinyl) benzene. Divinylbenzene is the particularly preferred compound of formula (D). The intervention of at least one compound of formula (D) can be advantageous in that in particular said compound tempers, in general, the effects of the compound (s) of formula (C). In particular, the beneficial action of such a compound of formula (D) on the expression of photochromic properties has been demonstrated. With reference to divinylbenzene, since this polymerized compound has a relatively high refractive index (n = 1.61), its action is also beneficial in that it leads to

  increasing the refractive index of the polymers of the invention.

  The polymerizable composition of the invention also advantageously contains at least one compound of formula (E). It is a (meth) acrylic monomer as defined above. It may especially be butyl, pentyl, hexyl, heptyl, octyl or 2-ethylhexyl (meth) acrylate or ethyltriglycol (meth) acrylate. 2-Ethylhexylmethacrylate (EHMA) is the preferred compound of formula (E). The presence of this type of compound has proved advantageous for the demolding of the polymerized material and for the implementation

  finishing treatments of the latter.

  Finally, the polymerizable composition may contain diallyl phthalate which makes it possible in particular to adjust the index and / or other optical and mechanical properties. As stated above, the intervention of compounds of formula (C) and / or (D) and / or (E) and / or diallylphthalate is not mandatory. She reveals herself

  however generally advantageous.

  The monomers of types (a), (b) and (f) and formulas (C), (D) and (E) are the main constituents - to the extent that they occur or are likely to occur in relatively consequent - polymerizable compositions of the invention from which the copolymers or resins of the invention are generated. Said copolymers are obtained from said monomers by a conventional radical copolymerization per se. Said copolymerization is generally carried out as specified above in the presence of an effective amount of at least one polymerization modifier and

  at least one radical polymerization initiator.

  The polymerization modifier generally occurs in a maximum content of 5% by weight, preferably 0.01 to 2% by weight, based on the weight of monomers to be copolymerized. It is noted here that it is possible to dispense with the presence of such a polymerization modifier in the event that the material is prepared at a reduced thickness (e <2.0 mm). In this case, it is not confronted with problems of heat evacuation ... For the preparation of a resin of the invention having a thickness greater than 2.0 mm, the presence of a polymerization modifier in the amounts indicated above is usually appropriate. It is strongly discouraged to exceed the maximum content of 5% indicated above because then the glass transition temperature of the prepared material becomes much too low. It is strongly recommended for the preparation of the material (lens) with a thickness of between 1.5 and 20 mm, a polymerization modifier content of about 1.2%. It has been noted that the colorability and darkening kinetics of the material of the invention increase with the amount of intervening polymerization modifier. In the same way, when this quantity increases, the mechanical resistance increases and

  the optical qualities are improving ...

  It is of course necessary that said polymerization modifier does not destroy the photochromic dye (s) possibly present during the

  polymerization and / or does not induce by itself a discoloration of the material.

  Said polymerization modifier is advantageously a chain transfer agent. Said chain transfer agent may be a chain transfer agent

  non-halogenated such as linear alkane-thiol or bis-mercaptoethyl ether.

  As an example of a linear alkane thiol, mention may be made of, but not limited to, dodecanethiol. It is not excluded to use other types of chain transfer agents such alkane thiols substituted by at least one aryl or alkyl radical or thiophenols. All these compounds are familiar to those skilled in the art and

commercially available.

  The initiator of radical polymerization or intervening catalyst must also be "inert" vis-à-vis the (s) photochromic (s) possibly present (s). The catalyst is generally used in a proportion of 0.01 to 1% by weight,

  preferably from 0.05 to 0.5% by weight, based on the weight of monomers present.

  Said initiator may be chosen from diazo compounds. These compounds are familiar to those skilled in the art and commercially available. Examples of

  such disazo compounds are azobisisobutyronitrile (AIBN) and 2,2'azobis (2-

  methylbutyronitrile) (AMBN). In the absence of such a catalyst or in the presence of a too small amount of it, it becomes necessary to carry out the copolymerization at a higher temperature and this makes the reaction difficult to control ... In the presence of Too much catalyst, an excess of free radicals can be generated, this excess of free radicals inducing destruction of the photochromic dye (s) possibly present (s) and accelerated fatigue of the final material. In this last hypothesis, the reaction

  can also accelerate and become difficult to control.

  The photochromic polymers of the invention contain, moreover,

  in their matrix an effective amount of at least one photochromic dye.

  Said dye is advantageously chosen from spiroxazines and chromenes (or a combination thereof) endowed with photochromic properties. Many photochromic dyes of this type are described in the literature and

commercially available.

  Spiroxazine dyes that can be used in the context of the present invention have in particular been described in US Pat. Nos. 3,562,172 and 4,634,767.

  4,637,968, 4,720,547, 4,756,973, 4,785,097, 4,792,224, 4,816,584, 4,831,142,

  4,909,963, 4,931,219, 4,936,995, 4,986,934, 5,114,621, 5,139,707, 5,233,038,

  4,215,010, 4,342,648, 4,699,473, 4,851,530, 4,913,544, 5,171,636, 5,180,524,

  166,345, in applications EP-A-0 508 219, 0 232 295 and 0 171 909 and in the

  application FR-A-2,738,248 (of the Applicant).

  It is particularly recommended, in the context of the present invention,

  the use of 1,3-dihydro-3,3-dimethyl-1-neopentyl-6 '- (4 "-N, N-

  diethylamino) -spiro-12H] -indole-2,3'-3H-naphtho [2,1-b] [1,4] oxazine, referenced SPO1 in the examples below and the use of spiroxazines

  described in Application FR-A-2,738,248.

  Chromic dyes which can be used in the context of the present invention are described in particular in US Pat. Nos. 3,567,605 and 4,889,413.

  4,931,221, 5,200,116, 5,066,818, 5,224,602, 5,238,981, 5,106,998, 4,980,089,

  130 058, and the application EP-A-0 562 915. Said chromenes can

  in particular consist of naphthopyrans.

  In this context, it is particularly recommended

  The use of 2,2-bis (4'-methoxyphenyl) -5,6-dimethyl- [2H] -

  naphtho [1,2-b] pyran, referenced CRI in the examples below.

  Spiropyran dyes, also usable in the context of the present invention, are described in particular in the following publications:

  PHOTOCHROMISM G. Brown, Publisher - Techniques of Chemistry -

  Wiley Interscience - Vol. 111 - 1971 - Chapter III - Pages 45-294 - R.C.

  Bertelson. PHOTOCHROMISM - Molecules & Systems - Edited by H. Durr - H. Bouas-Laurent - Elsevier 1990 - Chapter 8: Spiropyranes - Pages 314-455 R. Gugliemetti. The teachings of all these documents are incorporated herein by reference. It is not excluded, from the scope of the invention, the intervention of other dyes

photochromic, such as fulgids.

  In the context of the invention, the intervention of spiroxazines and / or

  chromenes is widely preferred.

  It has been indicated that the compositions of the invention for generating a photochromic resin contain an effective amount of at least one photochromic dye. It is indeed common, in the context of the present invention, to involve a combination of photochromic dyes, in order to obtain in the darkened state, a specific hue. In the context of particularly preferred embodiments of the invention, the intervening photochromic charge comprises a combination of chromenes. A particularly preferred combination is that of chromenes referenced CR2 and CR3 in the

  examples below, corresponding respectively to 2- (p-

  dimethylaminophenyl) -2- (p-methoxyphenyl) -5-methyl-7,9-dimethoxy

  [2H] -naphtho- [1,2-1) b Ipyran and 3- (p-methoxyphenyl) -3-phenyl-6-

  morpholino- [3H] -naphtho- [2,1-b] pyran. This combination makes it possible to obtain a

interesting gray color.

  By way of indication and in no way limiting, it is indicated here that said photochromic dyes are generally incorporated in the compositions to be polymerized (and polymerized) of the invention at a rate of 0.01 to 1% by weight, advantageously

  0.05 to 0.5% by weight, based on the total weight of monomers.

  The said photochromic dyes may also contain, in their chemical formula, a polymerizable and / or crosslinkable reactive group. They then intervene themselves as comonomers in the composition to be polymerized; and are chemically bonded to the matrix of said polymerized composition. In general, the resins of the invention, obtained from a composition comprising a mixture of at least two types (a) and (b) of different difunctional monomers as specified above,

  contain their photochromic dye (s), free or linked to their matrix.

  According to another of its objects, the invention relates to the resin obtained by

  radical radical copolymerization per se of the composition of the invention.

  Said resin may or may not have photochromic properties. When at least one photochromic dye intervenes within it to confer on it such photochromic properties, it has been added upstream of the copolymerization in the polymerizable composition or downstream of said copolymerization (introduction

  per se by diffusion in the resin).

  Finally, a third object of the invention consists of photochromic or non-photochromic ophthalmic articles made wholly or in part of a resin of the invention. Non-limiting examples of such articles are ophthalmic corrective lenses, solar lenses, glazings for vehicles or for buildings. In these articles, the possibly photochromic material of the invention may constitute the entire thickness of the article (mass article) or constitute only a laminated film or layer applied to

a support.

Examples

  The invention is illustrated by Examples I to 18 and I la, 12a and 15a hereinafter.

  Examples 1 to 9 relate to compositions of the invention which include in their formulation a photochromic dye of the chromene (CRI) or spiroxazine (SPOI) type. Examples 10 to 18 describe compositions of the invention containing a combination of two photochromic dyes of the chromene type (CR2-CR3: particularly preferred combination). Said examples (Tables I and 2) make it possible, among other things, to highlight the interesting optical and photochromic properties of ophthalmic lenses obtained from the compositions of the invention. Examples TI1 to T7 (Table 3) are given for comparison. They relate to control compositions which do not include in their formulation a combination of at least one short-chain (meth) acrylic difunctional monomer and at least one difunctional monomer.

  long chain alkenyl, an association characterizing the compositions of the invention.

  Examples 1a, 12a and 15a (Table 4) relate respectively to the compositions of the invention described in said Examples 11, 12 and 15, with the only difference that they do not contain photochromic dye in their formulation. It has been demonstrated by the Applicant that the compositions of the invention, whether they contain photochromic dyes or not, exhale identical mechanical properties. By way of comparison, the Applicant used as a control, for the comparative measurements of the mechanical properties, a photochromic lens marketed under the name TRANSITION PLUS, by TRANSITION OPTICAL, INC (example T8 - Table 4). The mechanical properties of this lens confirm that, according to the prior art, to express photochromic properties, it is often necessary to sacrifice the

  mechanical properties of said lens.

  All the proportions indicated in said examples I to 18, 1a, 12a, a and TIl to T7 are in parts by weight, for the various monomers involved in the formulation (monomers of type (a), type (b) and other monomers), and in weight% expressed relative to the total weight of monomers involved in the formulation, for the polymerization modifier, the polymerization initiator and the dye (s). The control T8, known under the name

  TRANSITION PLUS is a modified ethylene glycol diallyl carbonate resin.

  In general, the long-chain alkenic difunctional oligomer (type (b)) involved in the compositions of the invention is obtained as described above, by reaction of at least one alkenylisocyanate derivative and a long chain difunctional monomer. Said oligomer is synthesized according to the experimental protocol as described below and relating to the preparation of RUDI 600 (see below): 500 g of polyethylene glycol 600 are heated at 45 ° C. in a reactor that is thermostated under a nitrogen sweep. 2.5 g of 4-methoxyphenol and 3 g of

  tin dibutyldilaurate are added to the reactor. 329 g of 3-isopropenyl-a, ta-

  dimethylbenzyl isocyanate (m-TMI) are then added to the reactor at a rate of about 300 g / hour. When the addition of m-TMI is complete, the mixture is left stirring at 50 ° C. for one hour. The product obtained (RUDI 600) is then brought to room temperature. It is thus ready to be mixed with the other monomer (s) and the other substrate (s) involved in the composition.

  radically polymerizable.

  The other difunctional alkenic oligomers of type (b) are prepared,

  in a general way, according to the same experimental protocol.

  In the case of oligomers of type (b) which have at least one function uree in their formula and which correspond to monomers of formula (B) which are symmetrical or asymmetrical, the procedure is generally carried out according to the following experimental protocol, specified for the synthesis of RUDI JEF 600. It is found in this case that the monomer of type (a) of formula (A) is mixed with the promoters of oligomer of type (b) in the same step: a thermostatically controlled glass reactor equipped with A thermometer, a stirrer, a nitrogen purge and a dropping funnel were charged with 400 g of DIACRYL 121 (AKZO), 355 g (0.58 moles) of polyoxyethylene diamine of average molecular weight (JEFFAMINE ED600 from HUNSTMAN CORPORATION) and 1.9 g of methoxyphenol. After complete dissolution of the methoxyphenol, 233 g (1.16 moles) of 3-isopropenyl-ota, α-dimethylbenzyl isocyanate (m-CYTEC TMI) are added dropwise over a period of 30 minutes under vigorous stirring (the reaction is highly exothermic). The reaction mixture is maintained during the addition of the TMI at a temperature of 30 C. After addition of the TMI, the temperature is maintained at C for 30 minutes. A copolymer consisting of monomers of type (a) and of monomer (s) of type (b) (RUDI JEF 600 in the present case) is then obtained which is colorless and is ready to be diluted with the other (s). ) monomer (s) that may be involved in the polymerizable composition (monomers, especially of formula (C), (D), (E), diallylphthalate). It will be noted that the monomer of type (b) of formula (B) can also, if desired, be prepared directly in the presence of all the types of monomers that can be involved in the polymerizable composition ("one-pot" reaction). This synthesis can also be carried out in a solvent or a mixture of solvent which is inert with respect to the isocyanate function. In this case, it will have to be eliminated, according to the traditional methods (Dean-Stark, evaporator, ...), before or after dilution of the other monomers that can intervene in the formulations of the various polymerizable compositions (monomers of

  formula (C), (D), (E), diallylphthalate).

  In fact, 2 mm thick specimens were prepared, which were tested to evaluate their optical quality and / or mechanical properties, as well as possibly their photochromic properties. These test pieces were obtained by carrying out the copolymerization of the polymerizable composition in a suitable mold under the following conditions: said polymerizable composition is slowly heated up to the beginning of the thermal degradation of the catalyst (radical polymerization initiator), degradation which generates free radicals. Once the temperature of 60 C is reached, it is maintained for 8 hours. The copolymerization is continued for 2 hours at 90 ° C. At the end of this heat treatment, the samples are demolded and

  annealed for one hour at 120 C. This gives test pieces of the material to be tested.

  It is noted that the heat treatment specified above is that used by the Applicant to obtain ophthalmic lenses from the

  polymerizable compositions of the invention, processed in the lens molds.

  The raw materials used in the examples are as follows: Monomers Monomers of type (a) DIACRYL 121 from AKZO Chemistry (Formula A) D121 (Bisphenol A dimethacrylate tetraethoxylated) Butanedioldimethacrylate (Formula A ') BDDMA Diethylene glycol dimethacrylate (Formula A') DEGDMA Monomers of type (b) [m-TMI + polyethylene glycol (M = 600)] (formula B) RUDI 600 [m-TMI + polyethylene glycol (M = 900)] (formula B) RUDI 900 [m-TMI + polypropylene glycol (M = 725)] (formula B) RUDI PPG 725 [m-TMI + polytetramethyleneglycol (M = 1000)] (formula B) RUDI PTMG 1000 [m-TMI + poly (oxyethylene) diamine * (M = 600)] (formula B ) RUDI JEF 600 [m-TMI + poly (oxyethylene) diamine * (M = 900)] (formula B) RUDI JEF 900 [m-TMI + poly (oxyethylene) diamine * (M = 2000)] (formula B) RUDI JEF 2000 [m-TMI + polycaprolactone (M = 530) 1 (Formula B ') RUDI PCL 530

  poly (oxyethylene) diamine 600, 900, 2000: JEFFAMINE ED600-ED900-

ED2001I of HUNSTMAN CORPORATION.

  Other monomers 3-isopropenyl-α, α-dimethylbenzylisocyanate (CYTEC) m-TMI Diethylene glycol DEG 2 -ethylhexylmethacrylate EHMA Benzylmethacrylate BzMA Pentaerythritoltetracrylate PETA Hydroxyethylmethacrylate HEMA Styrene STY Divinylbenzene DVB Catalyst (radical polymerization initiator) 2,2'-azobis (2-methylbutyronitrile) ) AMBN Polymerization modifier n-Dodecane-1-thiol DDT Photochromic dyes Chemical type Designation Spiroxazine SPO ** Chromene CRI *** Chromene CR2 **** Chromene CR3 ***** C. hromene

  SPOI: 1,3-Dihydro-3,3-dimethyl-1-neopentyl-6 '- (4 "-N, N-diethylamino) -spiro

  [2H] -indole-2,3'-3H-naphtho- [2,1-b] [1,4] oxazine, marketed by James

Robinson Limited.

  CRI 2,2-bis (4'-methoxyphenyl) -5,6-dimethlyl- [2H] -naphtho- [1,2b] pyran, available from James Robinson Limited.

  2- [2- (p-dimethylaminophenyl) -2- (p-methoxyphenyl) -5-methyl-7,9-

  dimethoxy- [2H] -naphtho- [1,2-b] pyran; this molecule falls within the scope of the main claim of the patent application FR 96 09384. The Applicant has

highlighted his interest.

  - * * * * CR3: 3- (p-methethoxyphenyl) -3-phenyl-6-morpholino [3H] -naphtho [2,1-

  b] pyran; this molecule falls within the scope of the main claim of the patent application WO-A-94 22850. The Applicant has highlighted its interest. The test pieces of material according to the invention (Examples 1 to 18 and 1a, 12a, 15a) were prepared, as well as those of control material not containing a long-chain vinyl difunctional monomer (Examples T1 to T7) by polymerizing in the above conditions, polymerizable compositions of which

  the formulations are specified in Tables 1 to 4 below.

  The photochromic properties of the materials obtained were evaluated by measuring two parameters: - the colorability = DOO-DO0; evolution of the optical density of a standardized sample (2 mm thick). Said sample, the optical density DO0 (before exposure), is exposed under a xenon lamp (40,000 lux). At the end of this exposure, the new optical density ODm / at the equilibrium of said sample, darkened, is measured. The measurement is made at the maximum absorption length of the dye; namely 628 nm for SPO1, 500 n for CRI, and 560 nm for CR2-CR3 (in the case of the CR2-CR3 mixture the measurement is carried out at 560 nm, wavelength corresponding to the maximum sensitivity of the eye) . The colorability or darkening ratio is quantified by the absolute value of the difference of said optical densities DOOm and DO0; in fact, the values of DO0 and DO have been indicated in the different tables; the half-lightening time: tl / 2 (s); which characterizes the kinetics of return to the initial state. At the end of the exposure under the above conditions (OD), said exposure is cut off and the time required for a return to DOm-DOff 2DO-DOO is measured; it is t 1/2: 2 The optical quality of the materials is determined by the appearance or not of optical constraints and / or optical inhomogeneities (ropes, gel particles ...) when said material is subjected to a polarized light. The optical quality is considered good (B), when few or no constraints and / or

  optical inhomogeneities appear, or bad (MV) in other cases.

  The mechanical properties and optical properties of the obtained materials were evaluated using a viscoelasticimeter (frequency I Hz) through the measurement of various parameters - the refractive index nd; dispersion vd; hardness (Shorc D); the glass transition temperature, determined by measuring the maximum of tangent 5: Tg (max, tg 6) (C). Said temperature is determined by dynamic mechanical analysis (DMA); these different parameters and their

  measurement method are familiar to the skilled person.

  the modulus of elasticity E '(GPa) measured at 25 ° C. and at 100 ° C. (at the rubber plateau). Those skilled in the art know that, for a thermo-linked polymer as desired, for ophthalmic applications, a Tg> 100 C, a high E 'at 25 C and a E' at 100 C not too low; said E 'at 100 C translating the softening ability of the lens during polishing or cutting and during

  surface treatments (anti-scratch or antireflection).

Table 1

  Formulation Ex.1 Ex 2 Ex 3 Ex 4 Ex 5 Ex 6 Ex 7 Ex 8 Ex 9

D121 80 80 80 80 80 80 80 80 -

BDDMA - - - - 25

DEGDMA - - 25

RUDI 600 - 20 20 - 50

RUDI 900 20 - -

RUDI PTMG 1000 - - 20 - -

RUDI PPG 725 - - - 20 - -

RUDI PCL 530 - - - 20 - -

RUDI JEF 600 - _ - - 20 -

RUDI JEF 900 - - - - - - 20 - -

  AMBN 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 N

  DDT 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

SPOI - - - - - 0,05 - -

  CRI1 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05

Photochromic properties

  DO0 0.06 0.06 0.06 0.06 0.06 0.06 006 0.06 0.06

  DOo 1.29 1.27 1.28 1.25 1.20 1.28 1, 32 1.24 1.44 tl / 2 lightening 50 s 65 s 65s 70s 70s 23s 55s 70s 35s Ootiae ouality BBBBBBBBB Co oI te ooi

Table 2

* note: Ex. 17: (2) / (1) = 40/600: Ex. 18 (2) / (1) = 30/70 Formulation Ex. 10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18 D121 52 67.6 - 53 67.6 39.8 53 53 BDDMA 12 - 25 25 - - - - - DEGDMA 12 - 25 25 - RUDI 600 24 32.4 50 - - RUDI JEF 600 - - - - - - 60.2 28.2 (1) 33 (1) RUDI JEF 900 50 47 32.4 - RUDI JEF 2000 - - - - - - 18.8 (2) 14 (2) BzMA - 17 - - 17 17 17 17 17 EHMA - 9.6 - 9.6 9.6 9.6 9.6 9.6 DVB - 16.2 - - 16.2 16 16.2 16, 2 16.2 AMBN 0.2 0.2 0.2 0.2 0.2 0.22 0.2 0.2 0.2 DDT 0.5 0.5 0.5 0.5 0.5 0, 0.5 0.5 0.5 CR2-CR3 0.075 / f ,, 911.075 / 0, .9, .075 /., Flo90.070? 0, o0, 0.o75 /),., 9 (o)? ,,) 75g., 90,075 / 0.0090.07510, .J90,075 / .0,009 Photochromic properties DO (0,0 6 0,06 0,06 0,06 0,06 0,06 0, 06 0,06 0, 06 DOoo 1.04 1.07 1.01 0.99 1.12 1.07 0.96 0.98 0.95 tl / 2 lightening 35 s 40 s 30 s 40 s 25 s 40 s 50s 30s 40s QOuality BBBBBBBBB Co bO O0i

Table 3

  Formulation Ex. TI Ex. T2 Ex. T3 Ex. T4 Ex. T5 Ex. T6 Ex. T7

D121 100 100 80 80 - - 80

STY - - 20 20 - - 20

TMI! / HEMA - 100 - -

TM l / DEG - 60

PETA .-- 40 -

AMBN 0.2 0.2 0.2 0.2 0.2 0.2 0.2

DDT 0.5 0.5 0.5 0.5 0.5 0.5 0.5

SPO I - 0.05 - 0.05 - - -,

CRI 0.05 - 0.05 - 0.05 0.05 -

  CR2-CR3 - - - - - o, 075.9 Photochromic properties

  DO0 0.06 0.06 0.06 0.06 0.06 0.06 0.66

  DOOo 0,95 1,56 1,00 1,33 0,95 1,40 0, 80 tl / 2 lightening 150 s 51 s 400 s 1000 s 250 s 130 s I 500 s OLDER MV MV B B B B B o Ln

Table 4

  | Ex. 1 Ex. 12a Ex. 15a Ex. T8 n / a 1,553 1,522 1,556 1,500 vd 38,4 49,1 38,2 57,0 Tg (max, tg 8) 0,20 0,18 0,20 0,24

(C) 104 124 108 94

  E ') o (GPa) 1.96 1.95 2.30 1.96 E'Inpoc (GPa) 0.31 0.50 0.43 0.20 hardness 85 85 87 82 (ShoreD) About the results given in these tables the following remarks may be made. Optical Efficacy (Tables 1, 2 and 3) The results show the beneficial effect of the combination of D121 (monomer of formula (A)) with at least one second monomer of type (b) difunctional vinyl long chain, on the optical quality of the material. Indeed, all the formulations of the invention corresponding to said examples 1 to 8, -11 and 14 to 18 have little or no optical constraints, unlike said TIl and T2 examples using only D121 and for which the optical qualities of the material are bad. In the case where a mixture of monomers of formula (A ') (Examples 9, 12 and 13) combined with a long-chain difunctional vinyl-type monomer (b) is used, it is found that the

  lens obtained from said composition does not lose its optical qualities.

  It is also noted that the optical qualities are correct for formulations containing either D121 and styrene (Examples T3, T4 and T7), or a short-chain difunctional monomer having a vinylmethacrylate unit (Example T5), or a combination of a monomer difunctional vinyl short chain (TMI / DEG) with a polyfunctional monomer short-chain methacrylate (PETA) (example T6). However, these compositions do not exhibit

  good photochromic properties, as we see below.

Photochromic properties

Table 1

  The results clearly show the very good photochromic properties of the materials of the invention. Thus, in all of said Examples 1 to 9, characteristics of flexible nanobiphasic polymer matrices, we observe that the kinetics of return from the dark state to the light state is very fast since: <tl 1/2 lightening <70 s for material samples containing a

  Chromene-type photochromic dye (CRI).

  Replacing said chromene with a spiroxazine family dye (SPOI1) slightly exalts the half-lightening time value.

  (Example 6: tl / 2 lightening = 23s).

Table 2

  Examples 10 to 18 show that the judicious combination of two photochromic dyes of the chromene type (CR2-CR3), within the nanobiphasic flexible matrix, creates a synergistic effect on the colorability and the kinetics of return of the dark state in the clear state. Indeed, for these different formulations, we observe a half-lightening time such that: 25 s <tl / 2 <50 s and an equilibrium optical density whose values (DOo) are between 0.95 and 1 12. We re-insists here on the interest of this association CR2 - CR3 in the measure

  o The color it generates (gray) is acceptable to the consumer.

Table 3

  The results of the control samples clearly demonstrate the interest of the polymerizable compositions of the invention for materials having to exhibit photochromic properties. Thus, we easily observe the poor values of the half-thinning time (130 s <tl / 2 <1500 s) obtained for said examples T3 to T6 relating to formulations having

acceptable optical qualities.

Mechanical properties

Table 4

  Said examples relating to non-photochromic compositions of the invention show that the materials obtained have viscoelasticity characteristics and mechanical properties equal to or even greater than those exhibited by the control example T8. Thus, the values of the modulus of elasticity at the rubber plateau E'1 00Coc (GPa) are better in the case of said examples 1a, 12a and 15a, while not being too high, thus avoiding the risk of breakage at "drop". - ball test ". The Applicant has verified that the intervention of dye (s) photochromic (s) in its resins, does not alter their mechanical properties. The resins according to Examples 1 to 18 have mechanical properties identical to those of non-photochromic lenses. This is not the case of the photochromic control lens (example T8) whose values of the temperature of the tangent maximum and the E 'at 100 C are too low, to present acceptable mechanical properties, in a non-photochromic context. The obtained materials (resins) from the polymerizable compositions of the invention thus have superior optical qualities and mechanical properties at least equal to, and generally superior to, those of the prior art materials, and furthermore are particularly suitable to be used as

photochromic materials.

Claims (13)

- Claims -   1. Radically polymerizable composition comprising a mixture of at least one or more difunctional monomers of type (a) and one or more difunctional monomers of type (b): the difunctional monomer (s) of type (a) corresponding to one or other of formulas (A) and (A ') below: + formula (A): R1 CH3   CH2 = C-C- (OCHR-CH2) -OC0C (CH2-CHRO) ICIC CH2   Wherein: R1, R'1, R and R ', which may be identical or different, are independently hydrogen or a methyl group; m and n are, independently, integers between 0 and 4 inclusive; and are advantageously independently equal to 1 or 2; X and X, which may be identical or different, are halogen and preferably represent chlorine and / or bromine; p and q are, independently, integers between 0 and 4 inclusive; + formula (A '): GOLD' He 1 H2CC- C- (O-R) -O-C-C = CH2 I He R1 O   in which: R1 and R'1, which are identical or different, are independently a hydrogen or a methyl group; R is a linear or branched alkyl radical containing from 2 to 8 carbon atoms, a cycloalkyl radical containing from 3 to 6 carbon atoms, an ether radical of formula (R'-OR ") in which R 'and R", identical or different, are independently a linear or branched alkyl radical having 2 to 4 carbon atoms; difunctional monomer (s) of (b) long-chain difunctional dienunctional oligomeric oligomer, which correspond to one or other of formulas (B), (B ') and (B ") ci -after: + formula (B): R3 R 'Ilx R CZ- (R-Y) n R'-Z'ZC R'4 R2 R '2   Wherein R1, R'1, R2 and R'2, which may be identical or different, are independently hydrogen or a linear or branched, advantageously linear, alkyl radical containing from 1 to 4 carbon atoms; and correspond particularly advantageously to a methyl group; R3 and R4, different, are independently hydrogen and alkenyl radicals having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms and particularly preferably isopropenyl radical; R'3 and R'4, which are different, are independently hydrogen and the other is an alkenyl radical containing from 2 to 6 carbon atoms, advantageously from 2 to 4 carbon atoms, and in a particularly advantageous manner an isopropenyl radical; Z represents a carbamate function (-NH-CO-O-), a thiocarbamate function (-NH-CO-S-) or a urea function (-NH-CO-NH-); Z 'independently of Z and advantageously respectively with respect to   Z represents a carbamate function (-O-CO-NIH-), a thiocarbamate function (-   S-CO-NHI-) or a urea function (-NH-CO-NH-); - R 'represents a linear or branched alkyl radical having 2 to 4 carbon atoms; - R, identical or different when n> 2, is a linear or branched alkyl radical having 2 to 4 carbon atoms; Y, identical or different when n> 2, is oxygen or sulfur; n is an integer defined such that the total number of carbon atoms, contained in the long chain located between the two Z and Z 'units, is at least 18 and advantageously is between 18 and 18. and 112 included; + formula (B '): R R'O R4 C-N x-O- (R-Y) _.- C R4 R2 R'2   R3 'wherein - R1, R2, R3, R4, R'1, R'2, R'3, R'4, R and Y are as defined above with reference to formula (B); n is an integer defined such that the total number of carbon atoms contained in the long motif chain (RY) n is at least 22 and advantageously between 22 and 104 inclusive; ; + formula (B "): R3 R3 R O R'I I / C-N 0 - (R-Y) - R'-Z '- C R'4 R4 1- X O () Y n 1 - 4 R2 R'2   wherein - R1, R2, R3, R4, R'1, R'2, R'3, R'4, R, R 'and Y are as defined above with reference to formula (B); Z 'is a carbamate function (-O-CO-NH-) or Z' is a thiocarbamate function (-S-CO-NH-); advantageously Z 'is a carbamate function; n is an integer defined so that the total number of carbon atoms contained in the long motif chain (R-Y) n-R 'is at least 22 and   advantageously between 22 and 104 inclusive.   2. polymerizable composition according to claim 1, characterized in that it contains one or more difunctional monomers of type (a) corresponding to the formula (A) wherein: - R1 and R'1, identical, are a methyl group; R and R ', which are identical, are hydrogen or a methyl group; m and n are independently 1 or 2; p and q are identical and equal to 0;   and advantageously R and R 'represent hydrogen and m = n = 2.   3. Polymerizable composition according to one of claims 1 or 2,   characterized in that it contains one or more alkenic difunctional oligomers of formula (B) and / or of formula (B ') and / or of formula (B "), wherein the long chain polyoxyalkylene and / or polymercaptoalkylene, represented by the unit (RY) nR 'in the case of oligomer (s) of formula (B) or of formula (B "), or by the unit (R-Y) n in the case of oligomer (s) of formula (B '), has a molecular weight of between 500 gmol'1 and 2000 gmol'l; and advantageously the molecular weight of said long chain is at least   600 g.mol-1 and less than 900 g.mo1-1.   4. Polymerizable composition according to any one of claims 1   at 3, characterized in that it contains one or more long-chain symmetrical difunctional alkenic oligomers of formula (B) and / or of formula (B ') and / or of formula (B "), in which R1, R 1, R2, R'2 are identical and represent a methyl group, R3 and R'3, identical, represent an isopropenyl radical and R4   and R'4, identical, are hydrogen.   5. Polymerizable composition according to any one of claims 1   at 4, characterized in that it contains one or more monomers of the type (b) corresponding to the formula (B) R 3 R 1 R 1 R 4 CZ- (RY) -n R'-Z'-C R 4 4 I nI R2 R '2   in which - R, R ', R 1, R 2, R 3, R 4, R' 1, R '2, R' 3, R '4 and Y are as defined above; Y advantageously representing oxygen; and (a) - Z and Z 'are carbamate functions of the respective formulas (-NH-CO-O-) and (-O-CO-NH-); n is an integer defined so that the total number of carbon atoms contained in the long chain between the two Z and Z 'units is between 18 and 112; and advantageously, in the case of a polyoxyalkylene chain, is between 24 and 112 and particularly advantageously between 26 and 50; or (f) - Z and Z 'are thiocarbamate functions of the respective formula (-NH-CO-S-) and (-S-CO-NH-) - n is an integer defined so that the total number of carbon atoms, contained in the long chain between the two Z and Z 'units, being between 18 and 108; and advantageously, in the case of a polyoxyalkylene chain, is between 24 and 108 and particularly advantageously between 28 and 46; or (y) - Z and Z 'are urea functions (-NH-CO-NH-) - n is an integer defined such that the total number of carbon atoms, contained in the long chain located between the two Z and Z 'motifs, being between 18 and 112; and advantageously, in the case of a polyoxyalkylene chain, is between 24 and 112, and in a manner   particularly advantageous between 28 and 50.   6. Polymerizable composition according to any one of claims 1   at 5, characterized in that it contains one or more monomers of type (b) -   difunctional vinyl oligomer - of formula (B) in which: Z and Z 'are urea functions (-NH-CO-NH-); R1, R2, R3, R4, R'1, R'2, R'3 and R'4 are as defined in claim 4; R 'represents an ethylene or propylene group; n is an integer equal to 13 or 19 defining a total number of carbon atoms, between Z and Z ', equal to 28 or 40 when (R-Y) n is a polyoxyethylene chain; or n is an integer equal to 10 or 14 defining a total number of carbon atoms, between Z and Z ', equal to 33 or 45 when (R-Y) n is a polyoxypropylene chain; where n is an integer between the lower limit values (n is between 10 and 13 inclusive) and the upper limit (n is between 14 and 19 inclusive), when (R-Y) n is   a mixed polyoxyethylene / polyoxypropylene chain.   7. Polymerizable composition according to any one of claims 1   at 5, characterized in that it contains one or more monomers of type (b) -   vinyl difunctional oligomer - of formula (B) in which: Z and Z 'are carbamate functions of the respective formula (-NH-CO-O-) and (-O-CO-NH-).   R1, R2, R3, R4, R'1, R'2, R'3 and R'4 are as defined in claim 4; - R 'represents an ethylene group; - (R-Y) n represents a long polyoxyethylene chain; n is an integer equal to 13 or 19 defining a total number of carbon atoms, contained in the long chain located between the two Z and Z 'units, equal to 28 or 40.   8. Polymerizable composition according to any one of claims I   at 7, characterized in that the amount of monomer (s) of type (a) is between 40 and 99 parts by weight, per 100 parts by weight of the mixture of monomers of type (a) and (b).   9. Polymerizable composition according to any one of claims I   at 8, characterized in that it contains, for 100 parts by weight of the monomer mixture of types (a) and (b), from 1 to 60 parts by weight of at least one monomer chosen from alkenic monomers, advantageously vinylic monomers and allylic,   (meth) acrylic monomers, and mixtures thereof.   10. Polymerizable composition according to claim 9, characterized in that it contains: (c) at least one aromatic monovinyl monomer of formula (C) Ri Q C = CH2   wherein R1 = H or CH3; said monovinyl monomer preferably consisting of styrene; and / or (d) at least one aromatic divinyl monomer of formula (D): Q (= C = CH2) 2   wherein R1 = H or CH3; said divinyl monomer preferably consisting of divinylbenzene; and / or (e) at least one (meth) acrylic monomer of formula (E) CH2 = C (R) -COOR '   in which R = H or CH3 and R 'is a linear or branched alkyl radical containing from 4 to 16 carbon atoms, an optionally substituted methylphenyl or methylphenoxy radical or a polyoxyethoxylated group of formula - (CH2-CH2-O) nR "in which n is an integer between 1 and R "= CH3 or C2H5; said (meth) acrylic monomer is advantageously 2-ethylhexylmethylacrylate and / or (f) diallylphthalate.   Polymerizable composition according to any one of the claims   1 to 10, characterized in that it further contains an effective amount of at least one photochromic dye imparting to said composition photochromic properties; said dye (s) being advantageously chosen from the group of spiroxazines, chromenes and mixtures thereof, and more advantageously consisting of at least one spiroxazine, at least one chromene or at least one chromene mixture (s).   12. Resin capable of being obtained by radical copolymerization   a polymerizable composition according to any one of claims 1 to 11.   13. Ophthalmic article consisting, in whole or in part, of a resin according to claim 12.