WO2002064665A1

WO2002064665A1 - Hydrophilic polymer material comprising a polyorganosiloxane crosslinked matrix and method for making same

Info

Publication number: WO2002064665A1
Application number: PCT/FR2001/003347
Authority: WO
Inventors: Michel Arotcarena; Chantal Belin; Philippe Chaumont; Laure DZIADOSZ; Bettina Heise; Catherine HENNEUSE; André LASCHEWSKY; David Pasquier; Anne Ripert; Markus Wasgindt
Original assignee: Ocular Sciences S.A.S.
Priority date: 2001-02-09
Filing date: 2001-10-26
Publication date: 2002-08-22
Also published as: FR2820746A1

Abstract

.The invention concerns a hydrophilic polymer material characterised in that it comprises a crosslinked polyorganosiloxane matrix including substituents bound to the silicon atoms bearing one or several zwitterionic groups.

Description

Hydrophilic polymeric material comprising a crosslinked matrix of polyorganosiloxanes and process for its manufacture

The present invention relates generally to a polymer material based on polyorganosiloxanes which has a hydrophilic character, in particular for the manufacture of optical articles such as contact lenses, as well as to a process for the manufacture of such a material. .

The present invention also relates to optical articles such as contact lenses, manufactured or coated with the polymer material based on polyorganosiloxanes.

It is desirable for the comfort of the user, that the contact lenses be made of a hydrophilic material having a high wettability in particular by the tear medium of the eye. In addition, it is known that contact lenses, when they are in the presence of the lacrimal medium of the wearer's eye, exhibit a tendency to accumulate on their surfaces deposits due to the species present in this lacrimal medium, such as proteins, lipids, etc.

Such deposits thus formed on the surface of the lens greatly reduce visual acuity and the wearer's comfort. In some extreme cases, in the absence of maintenance of the lens, an inflammatory and immune reaction of the eye to protein deposits occurs and can cause giant papillary conjunctivitis.

Furthermore, in the case of hydrophilic soft lenses, their disinfection by boiling still denatures the protein materials, which coagulate, which leads to the formation of white and opaque deposits.

It is therefore desirable to be able to have contact lens materials which, by their nature, are hydrophilic and have high wettability by the lacrimal medium and a low tendency to accumulate deposits, in particular proteinaceous materials.

Documents EP-A-555,295 and EP-A-563,293 describe inter alia crosslinked polymers obtained by copolymerization of a zwitterionic monomer and a neutral diluent monomer. Contact lenses made from such copolymers have reduced fouling. Silicones, in particular crosslinked silicones, such as polyorganosiloxanes, exhibit a combination of optical and mechanical properties which make them prime candidates for the manufacture of optical articles such as contact lenses. Unfortunately, these crosslinked silicones have a very pronounced hydrophobic character, which greatly limits their use in ophthalmic optics and other applications requiring a material having a hydrophilic character.

To remedy this problem, it has been proposed in document EP-A-317.377 from the company ESSILOR to treat contact lenses obtained by molding polydimethylsiloxanes epoxidized in the mass by soaking the lenses in a solution of glucuronic acid to impart them hydrophilic character.

Besides the fact that the solution recommended in this document EP-A-317.377 requires an additional impregnation step, the hydrophilic nature of the impregnation is difficult to adjust. In particular, in ophthalmic application, it is desirable for the material to be essentially hydrophilic on its surface, which is difficult to achieve by the impregnation method, as described in patent EP-A-317,377.

It would therefore be desirable to have another hydrophilic polymer material based on crosslinked silicones, in particular crosslinked polyorganosiloxanes.

The present invention therefore relates to a polymeric material based on crosslinked polyorganosiloxanes, in particular on polydimethylsiloxanes (PDMS) and / or crosslinked polymethylphenylsiloxanes, which has a hydrophilic character, in particular at the surface.

The present invention also relates to a method of manufacturing such a material. The present invention also relates to optical articles; in particular contact lenses made from the hydrophilic crosslinked polyorganosiloxane material.

According to the invention, the hydrophilic polymer material based on polyorganosiloxanes comprises a crosslinked matrix of one or more polyorganosiloxanes characterized in that the one or more polyorganosiloxanes of the crosslinked matrix have substituents linked to silicon atoms which carry one or more zwitterionic groups.

Preferably, the polyorganosiloxanes are chosen from polyalkylsiloxanes such as polydimethylsiloxanes, polyalkyl aryl siloxanes such as polymethyl phenyl siloxanes and polydialkyl alkyl aryl siloxanes such as polydimethyl methyl phenyl siloxanes. More preferably, the polyorganosiloxanes of the invention contain trialkylsilyl end groups, in particular trimethylsilyl. The substituents bearing one or more preferred zwitterionic groups are the substituents bearing sulfobetaine groups.

The polyorganosiloxanes suitable in the present invention can be defined as polyorganosiloxanes comprising the units of formulas:

Si0 _{_2/2} (II) and R ^D Si0 _2/2 (III)

in which R and R represent an alkyl radical, in particular a CrC ₄ alkyl radical and preferably the methyl radical, or an aryl radical, preferably phenyl;

R represents an alkyl radical, in particular an alkyl radical Cj-

C, preferably the methyl radical, or an aryl radical, preferably the phenyl radical; R ⁴ represents a substituent carrying at least one zwitterionic group and R represents an alkyl group, in particular a CC ₄ alkyl group, preferably a methyl group, or an aryl group, preferably a phenyl group, the remaining valence of the silicon atom of the motif of formula (III) being linked by an organic crosslinking residue to another silicon atom.

Preferably, R, R, R and R all represent a methyl group.

The proportion of units of formula (II) comprising a substituent carrying at least one zwitterionic group must be sufficient to confer on the crosslinked matrix of polyorganosiloxanes the character hydrophilic required. Generally, this proportion represents 5 to 50%, preferably 15 to 30%.

Also, the proportion of crosslinking units of formula (III) must be sufficient to give the crosslinked polyorganosiloxane matrix an appropriate crosslinking rate to obtain the desired mechanical properties. In general, the proportion of crosslinking units of formula (III) will be between 0.1 and 50%, preferably 1 to 10%.

The substituents carrying at least one zwitterionic group represented by R4 may be any group containing at least one zwitterionic group, such as those described in documents WO 94/14897, EP-A-555.295 and EP-A-563.293.

In general, the zwitterionic group can be represented by the formula:

in which :

R ⁶ represents an alkylene, cycloalkylene, aromatic group, optionally containing in its chain one or more heteroatoms;

7 RR and R represent, independently of one another, a hydrogen atom, a CH ₂ -R ^{10 group} in which R ¹⁰ may be a hydrogen atom, an alkyl radical, a CH ₂ -R group ¹¹ in which R ¹¹ is a substituent optionally comprising heteroatoms, a group

• 7 R phenyl provided that at least one of R or R is an atom

7 R of hydrogen, or R and R, identical or different, may constitute a ring optionally comprising one or more additional heteroatoms;

R ⁹ represents an alkylene or substituted alkylene group, optionally comprising in its chain one or more heteroatoms; and R ⁷ and R ⁹ may, jointly, form a ring or a polycyclic structure optionally comprising one or more heteroatoms. In particular, R ⁶ can be a spacer arm, preferably comprising one or more heteroatoms and better still an ethylene oxide arm, represented by the formula:

where n is an integer from 1 to 20.

In addition, if R contains a group

this must be located at least 3 carbon atoms from the silicon atom.

Preferably, R ⁹ represents a group:

CH,

-CH ₂ CH ₂ N - (-CH ₂ )

R ¹²

in which x is an integer from 1 to 20, q and r are integers from 1 to 20 and R is an alkyl, cycloalkyl or aryl group optionally comprising one or more heteroatoms in their chain.

As an example of a polycyclic structure formed jointly by R ⁷ and R ⁹ , mention may be made of the structure:

Examples of preferred zwitterionic groups are

H CH ₂ - CH ₂ 4-CH ₂ - N ⁺ hCHH S0 ₃

-CH CH ₂ ~ S - CHo "" CH? N ⁺ fcH ₂ V-S0 ₃

OH

CH ₂ CH CH ₂ CH ₂ - NH ⁺ CH ₂ CH ₂ CH ₂ C00 ^'

CH, CH,

-CH ₂ CH CH ₂ CH ₂ - NH ₂ - CH ₂ CH ₂ CH ₂ C00 ^"

CH,

-CH ₂ CH CH ₂ 0 P 0CH ₂ CH ₂ N ⁺ (CH ₃ ) ₃

CH ₃

where x is an integer from 2 to 10 and n and p are integers from 1 to 20.

Among these zwitterionic groups, the zwitterionic sulfobetaine groups of quaternary ammonium are recommended. Crosslinked polyorganosiloxanes comprising substituents linked to silicon atoms and carrying one or more zwitterionic groups can be obtained by 3 main different synthetic routes, from SiH, Si-vinyl precursors. These 3 routes are detailed below: 1) Crosslink a composition of at least one polyorganosiloxane oligomer with SiH functions and at least one polyorganosiloxane oligomer with Si-vinyl functions with at least one of the two oligomers carrying sites such as epoxy or chloromethylstyrene (VBC) functions on which zwitterionic compounds or their precursors are capable of being grafted

(in the general diagram, only the case where the SiH oligomer carries the site to be grafted is shown), then carry out the appropriate reactions leading to the final product.

Alternatively, a composition of at least one polyorganosiloxane oligomer with SiH functions and at least one polyorganosiloxane oligomer with Si-vinyl functions can be reacted in a single step, in the presence of at least one cyclic sixolanic monomer carrying at least a function onto which a zwitterionic compound or a precursor thereof, or of a vinyl monomer carrying at least one zwitterionic group or a precursor thereof, and, where appropriate, final conversion, can be grafted of these in zwitterions.

2) Prepare an SiH or Si-vinyl oligomer carrying a zwitterionic function or a precursor thereof, crosslink, then if necessary, transform the precursor into a zwitterion;

3) Reacting at least one siloxane monomer with SiH functions and at least one siloxane monomer with Si-vinyl functions, in the presence of a cyclic siloxane monomer carrying at least one zwitterionic group or precursor thereof, and the case if necessary, final conversion of these into zwitterions. These summary diagrams are illustrated in Figure 1.

More specifically, the hydrophilic material based on crosslinked polyorganosiloxanes according to the invention can be prepared by reaction of at least one reactive compound carrying one or more zwitterionic groups or precursors of zwitterionic groups, by hydrosilylation reaction with part of the hydrogenosilyl groups of one or more polyhydrogenoorganosiloxanes, then optionally in the case of reactive compounds carrying precursor groups of zwitterionic groups reaction of transformation of the precursor groups into zwitterionic groups, and crosslinking of the hydrogenosilyl groups remaining of the polyhydrogenoorganosiloxane (s) by hydrosilylation reaction with an agent of crosslinking.

As a variant, the materials according to the invention can be prepared by first crosslinking the polyhydrogenoorganosiloxane (s) by hydrosilylation reaction of part of the hydrogenosilyl groups thereof with a crosslinking agent and then grafting by hydrosilylation reaction on the hydrogenosilyl units remaining of the reactive compounds carrying at least one zwitterionic group or a precursor group of zwitterionic group and optionally by transforming the precursor group or groups of zwitterionic groups into zwitterionic groups.

The symbols used for cyclic siloxanes and silicone oligomers are shown in Figure 2.

The SiH, Si-vinyl oligomers used in the context of the present invention are commercial products or synthesized specifically to provide them with a suitable structure in the context of the invention.

In particular, the SiH type oligomers can be synthesized from cyclic monomers according to the following reaction scheme:

O ligomere polysiloxane to

M, groups S iH

O l igomer polysiloxane to

M, S iH telechelic groupings

According to the above schemes, a monomer (octamethyltetracyclosiloxane) is reacted

with a monomer (tetramethylcyclotetrasiloxane)

and either a hexamethyldisiloxane

or a tetramethyldisiloxane

H Si- -Si-

In the latter case, it is possible to prepare telechelic polysiloxane oligomers, that is to say carrying an SiH function at the two chain ends.

The polysiloxane oligomers carrying zwitterionic groups or of precursors thereof can be obtained by reacting commercial siloxane oligomers, or prepared according to the process described above; from cyclic monomers, with reactive compounds carrying zwitterionic groups or precursors of zwitterionic groups.

Preferably, one or more polyhydrogenoorganosiloxanes are reacted by hydrosilylation reaction comprising units:

R ¹ R ² SiO _2/2 (I) and / or R ³ SiO _2/2 (IV)

in which R, R and R are defined as above with a reactive compound of formula:

CH ₂ = CH-R (V)

in which R is a radical carrying one or more zwitterionic groups or precursors of zwitterionic groups to form a polyhydrogenoorganosiloxane comprising units of formulas:

R'R ^ ÎO _J Λ (1) and / or R Si0 _2/2 (II) and R ³ Si0 _2/2 (VI)

CH,

where R, R, R and R are as defined above and in the case where R is a group carrying precursor groups of zwitterionic groups, the precursor groups are transformed into zwitterionic groups.

The material according to the invention is obtained by crosslinking of the polyhydrogenoorganosiloxane comprising units of formula (VI) by hydrosilylation reaction of the groups:

remaining by means of a crosslinking agent, to form a crosslinked polyorganosiloxane according to the invention comprising

1 7 formulas (I), (II) and (III). As indicated above, R, R and R preferably represent a methyl group.

As also indicated above, the preferred zwitterionic groups are the sulfobetaine groups.

The reactive compounds carrying one or more zwitterionic groups recommended according to the invention are compounds comprising ethylenic unsaturation and corresponding to formula (V).

Among these ethylenically unsaturated compounds, there may be mentioned N- (3-sulfopropyl) -methacryloyloxyethyl-N, N-dimethylammonium-betaine, N- (3-sulfopropyl) -N-vinylnonyl-N, N-dimethylammonium-betaine, N- (3-sulfopropyl) -N-methacrylamido-propyl-N, N-dimethylammonium-betaine, l- (3-sulfopropyl) -2-vinyl-pyridinium-betaine, N-methacryloyloxy ethyl-N, N- dimethyl-N, 2-ethylcarboxy-betaine, N- (3-carboxylpropyl) -N-methyl-aminoethylmethacrylate, N- (3-carboxypropyl) -N-methylamino-methacryloyloxyethyl-N, N- dimethylammonium-betaine, N - (3-carboxypropyl) aminoethylmethacrylate, and 2- (methacryloyloxy) ethyl-2-

(Trimethylammonium) ethyl phosphate.

Among the reactive compounds with precursor groups of zwitterionic groups, the recommended reactive compounds are the reactive compounds comprising precursor groups of sulfobetaine corresponding to the formula:

in which R 'is a divalent organic residue and R "represents H or an alkyl group, preferably the CH ₃ group. The reactive compounds with precursor groups are grafted to silicon atoms of the polyhydrogenoorganosiloxane by hydrosilylation of units of formula:

then the amino function of the units of formula (VIII) is reacted with γ-propanesultone

to obtain the sulfobetaine function and thus motifs of formula:

R "R ³

S0 ₃ - (CH ₂ ) _{3 N} ⁺ R'CH ₂ CH ₂ - Si0 _2/2 (IX)

R "

As indicated above, the proportion of hydrogenosilyl units of the polyhydrogenoorganosiloxane which react with the reactive compound carrying one or more zwitterionic groups or precursors of zwitterionic groups is lower than the total proportion of the hydrogenosilyl units present in the polyhydrogenoorganosiloxane in order to allow crosslinking thereof. . This crosslinking can be carried out in a recommended manner, by hydrosilylation reaction of the remaining hydrogenosilyl units using a siloxane oligomer comprising diorganosiloxane units and organovinylsiloxane units of formulas:

1 7 ^ in which R, R, R are as defined above. Alternatively, since only the surface of the material, for example in the case of an application to contact lenses, must have a hydrophilic and biocompatible nature, the steps of the process can be reversed, that is to say start by crosslinking and then grafting the substituent carrying zwitterionic groups or precursors of zwitterionic groups on the material already crosslinked. In this case, more activity can also be expected when reactive compounds with precursor groups are used, in particular an amino precursor group located on the surface rather than inside the matrix.

Hydrosilylation reactions, that is to say the SiH-olefin addition reactions are well known.

Many types of platinum catalysts for this SiH-olefin reaction are known and such platinum catalysts can be used for the hydrosilylation reaction of the present invention. When optical transparency is necessary, the preferred platinum catalysts are catalysts based on platinum derivatives which are soluble in the reaction mixture. The platinum derivative can be chosen from those corresponding to the formula Pt-Cl -olefin or HPtCl ₃ -olefin which are described in US Patent 3,159,601. The olefin indicated in the two preceding formulas can be any olefin but is preferably an alkene having from 2 to 8 carbon atoms, a cycloalkene having from 5 to 7 carbon atoms or styrene. The specific olefins which can be used in the above catalyst formulas are ethylene, propylene, the various isomers of butylene, octylene, cyclopentene, cyclohexene, cycloheptene, etc.

Another type of platinum catalyst which can be used in the present invention is the complex of platinum chloride with cyclopropane described in US Pat. No. 3,159,662.

The platinum catalyst can also be a complex formed by chloroplatinic acid with up to two moles per gram of platinum of a product chosen from alcohols, ethers, aldehydes and their mixtures, complex which is described inter alia in US Patent 3,220,972. Other useful platinum catalysts are also described in US Patents 3,715,334, 3,775,452 and 3,814,730.

Regarding this addition hydrosilylation reaction

SiH olefin, reference may be made to the article by J.L. SPIER,

"Homogeneous catalyze of hydrosylation by transition metals", 5 (Advances in Organometallic Chemistries, Vol. 17, pages 407 to 447 published by The Académie Press (New York, 1979).

Specialists can easily determine an effective amount of platinum catalyst. Generally, an effective amount is in the range of 0.1 to 50 ppm relative to the total composition of organopoly siloxane.

In the following examples illustrating the present invention, unless otherwise indicated, all parts and percentages are expressed by weight.

5 EXAMPLE 1

1) Synthesis of a polysiloxane oligomer with zwitterionic properties

In a dry 50 ml flask fitted with a reflux condenser, a thermometer and a stirrer, 101 mg of a polyhydrogenomethylsiloxane oligomer of formula:

550 mg of a zwitterionic monomer of formula:

as well as 25 ml of dry and previously distilled isopropyl alcohol. 170 ml of a platinum polymerization catalyst solution (H ₂ PtCl ₆ 6H ₂ 0.3 mg dissolved in 10 ml of anhydrous isopropanol) are introduced. The mixture is stirred at 65 ° C for 4 days. It is then subjected to evaporation. Then a purification is carried out by dialysis in methanol.

4 fractions are recovered: the ^1st fraction: 0.63 g consisting mainly of the starting reagents (IA) and (IB) and traces of the poly siloxane oligomer with zwitterionic properties ZwSiOL].

^2nd fraction: 0.1 g consisting of oligomer SwSiOLj and remains of the starting reactants (IA) and (IB). 3 ^rd fraction: 0.02 g of the oligomer consisting ZwSiOL] and traces of the starting reagent (IA) and (IB).

4 ^th fraction: 0.04 oligomers ZwSiOL] pure. This oligomer is soluble in methanol, insoluble in chloroform.

The NMR spectrum of this 4 ^th fraction corresponds to the expected product ZwSiOL].

The average molar mass of this is 6293 g with 24 SiH per chain, ie 3.8 x 10 ^" SiH / g.

2) Preparation of molded articles The polysiloxane oligomer with zwitterionic properties ZwSiOLi synthesized previously is introduced into a mixture of siloxane prepolymers developed by Rhone-Poulenc under the reference RTV 70- 141A and B (Silbione ^®).

Oil A consists of mono and divinyl polydimethylsiloxanes and a platinum catalyst.

This part contains approximately 37 milliequivalents of vinyl functions per 100 g of polymer.

Oil B is a hydrogenopolydimethylsiloxane and contains approximately 847 milliequivalents of hydrogenosilane functions per 100 g of polymer.

A composition is prepared by mixing

2 g RTV 70-141 A oil

0.169 g RTV 70-141 B oil

0.04 g of the ZwSiOL oligomer, [SiH]

In this mixture, the molar ratio = 1.2.

[If - vinyl]

Polyamide molds are filled with this composition and the composition is subjected to the following thermal polymerization cycle:

8 hours at 64 ° C, then temperature rise to 83 ° C in 10 minutes, followed by 15 hours at 83 ° C.

After demolding, hydrophilic lenses are obtained.

EXAMPLE 2 Preparation of a telechelic SiOL ₂ oligomer (carrying an SiH function at the two chain ends).

D ' ₄ (OR D ₄ H ₄ )

SlOL ₂

(M ' ₂ )

Octamethylcyclotetrasiloxane (D ₄ ), tetramethylcyclotetrasiloxane D ₄ H ₄ (or D ') and a tetramethyldisiloxane (M' ₂ ) obtained from the company ACBR are used.

Each of these reagents is dried and then distilled. 0.79 g of tetramethyldisiloxane (M ' ₂ ) is then introduced into a two-necked flask provided with an opening for the introduction of gas and connected to a tap for connection with a vacuum pump, then 23.97 g of octamethylcyclotetrasiloxane D ₄ and 15.30 g of tetramethylcyclotetrasiloxane D ' ₄ . 0.20 g of catalyst TONSIL ^® (HC1 absorbed onto the clay) of the company Sud Chemie AG is added.

The flask is then closed, immersed in liquid nitrogen and the mixture is degassed by applying vacuum. The flask is allowed to return to room temperature. Next, the reaction mixture is placed in an argon atmosphere.

The polymerization is carried out at 60 ° C. with magnetic stirring for 6 hours.

At the end of the reaction, the TONSIL ^® catalyst is removed by filtration through a porous filter of polytetrafluoroethylene (pore diameter of 45 .mu.m).

Heptane is used to rinse the flask and for filtration to reduce the viscosity.

The filtered product is recovered and the heptane is removed by evaporation, then the volatile cyclic oligomers are removed by heating at 140 ° C under a pressure of 0.01 mm of mercury for 30 minutes.

The product obtained which is a telechelic polyhydrogenomethylsiloxane oligomer having units:

and SiH motifs at the end of the chain.

This oligomer, designated by SiOL _2, has the following characteristics:

The above operating procedure is repeated twice and ultimately polyhydrogenomethylsiloxane oligomers are obtained. SiOL ₃ and SiOL ₄ telechelics with some differences in their characteristics:

EXAMPLE 3

Synthesis of an oligomer carrying grafted amino functions.

FSiOL,

In a 100 ml flask, 0.167 g of dimethylallylamine is mixed with 2 ml of toluene and degassed with argon for 15 minutes. Then, 3.8 mg of Pt / C (Platinum on carbon from the company ALDRICH) are added and mixed with the solution for 15 minutes under argon, then 3 g of the oligomer SiOL ₂ synthesized previously are added.

The reaction is carried out at 55 ° C for 6 hours with stirring. The mixture is then diluted with toluene and then filtered through a polytetrafluoroethylene (PTFE) filter with a porosity of 45 μm to remove the remaining catalyst. The toluene is then evaporated by means of a rotary evaporator connected to a vane pump.

A colorless liquid is obtained.

The characteristics of this FSiOL ₂ liquid.

The NMR spectrum conforms to the expected formula.

Transformation into zwitterion

FSiOL, ZwSiOL _?

1 g of FSiOL ₂ previously synthesized, mixed with 10 ml of toluene and 10 ml of acetonitrile, is poured into a 150 ml flask. / 064665

23

The mixture of solvents ensures perfect homogeneity in the system.

After degassing with argon, 0.1 ml of propanesultone are added (ie a 70% excess compared to the stoechimetry).

After 15 hours of reaction, the solvents are removed by evaporation.

A viscous and milky liquid is obtained.

It has the following characteristics:

Manufacture of molded articles:

ZwSiOL ₂

hydrophilic crosslinked polymer.

0.05253 g of zwterionic oligomer ZwSiOL ₂ obtained above (corresponding to 2.68 × 10 ⁻⁴ mole of SiH function) and 1.029 g of RTVA resin (corresponding to 2.88 × 10 ⁻⁴ mole of Si— functions are mixed vinyl) in a mixture of toluene and methanol which promote homogenization of the mixture.

[SiH]

The molar ratio = 0.93.

[If - vinyl]

The mixture is poured into a polyamide mold and the solvents are evaporated before crosslinking. Crosslinking is carried out by heating at 120 ° C for 2 hours. EXAMPLE 4

The following example illustrates the synthetic route No. 3 appearing in the summary diagram of FIG. 1. The steps 1 and 2 are aimed at synthesizing the cyclic reagent siloxane zwitterionique.

D ₄ H ₃ (C ₃ N)

In a three-necked flask, 9.30 g (109.2 mmol) of N, N-dimethyl allylamine (from the company MERCK) are degassed under argon for 15 minutes. Then 213 mg (10 ^"3 equivalents of amine) of Pt / C are added to the amine.

Then, 21.89 g (91.02 mmol) of 1,3,5,7-tetramethyl-cyclotetrasiloxane (D ₄ H ₄ ) are added slowly.

The mixture is then maintained at 55 ° C (below the boiling point of the amine) for 6 hours with stirring.

Then the mixture is diluted in toluene, and filtered through a porous polytetrafluoroethylene type filter, with a pore diameter of 45 μm, in order to remove the catalyst from the platinum.

The toluene is evaporated from the liquid product obtained. Then, the liquid product is immediately distilled under a pressure of 0.1 mm Hg (boiling point = 62 ° C). The product is very sensitive to humidity and oxygen. It is therefore imperative to avoid contact with air.

The NMR spectrum is in accordance with the expected product (DH ₃ (C ₃ N)). 2nd step

D ₄ H ₃ (C ₃ NZw)

In a 150 ml flask, 5 g of D ₄ H ₃ (C ₃ N) obtained during the previous step are diluted in 50 ml of acetonitrile and degassed with argon. Then 1.35 ml of propane sultone are added.

The mixture is heated at reflux for 5 hours.

The solid part is filtered and rinsed with acetonitrile to remove the excess propane sultone. Then, the solid is dried under vacuum. A white crystallized solid is obtained.

Synthesis of an SiOL ₅ oligomer The synthesis of an SiOL ₅ oligomer is carried out by following the same procedure as in Example 2, but using the following quantities of reagents: 31.41 g of D ₄ 8.21 g of D ' ₄ 0 , 47 g of M ' ₂ 0.2 g of TONSIL ^® The heating is carried out at 60 ° C. A product is obtained having the following characteristics:

Manufacture of molded articles The reaction is as follows

D ₄ H ₃ (C ₃ NZw) + oligomer SiOL ₅

+ Si-CH group oligomer = CH ₂

crosslinked polymer

0.05222 g of D ₄ H (C ₃ NZw) are mixed with methanol in sufficient quantity to obtain its dissolution and to obtain a first Si solution. In parallel, 0.3086 g of SiOL ₅ oligomer and 4.235 g of RTVA and a small amount of toluene are mixed to obtain a second solution S.

The two solutions S] and S ₂ are then mixed and placed in a desiccator.

The solvents are then evaporated by evacuation at room temperature.

Next, a mold is filled, the molding surfaces of which are planar optical surfaces. The open mold is placed in a desiccator and degassed by vacuum drawing at room temperature.

The mold is then closed and the polymerization is carried out by heating in an oven for two hours at 120 ° C.

Let cool. After demolding, a flat sample 0.2 mm thick and 15 mm in diameter is obtained.

We measure its properties.

wettability

Entrance angle: 108 Exit angle: 41

Hysteresis: 67

Refractive index n = 1.409

Permeability 80 ml (0 ₂ ) cm / cm .s.mm Hg

Mechanical properties Stress at break 0.75 MPa ± 0.09

Elongation 112% ± 11%.

EXAMPLES 5 to 20

The following examples illustrate the synthetic route No. 1 I - Preparation of functionalized silicone matrices IA - Preparation of precursors

IA. l - Functionalization of a siloxane oligomer SiOL, ₂ by grafting of allylglycidyl ether

(AGE)

SiOL ₂ EPO

The amount of allylglycidyl ether (AGE) to be grafted is chosen so as to maintain in the epoxidized oligomer (SiOL ₂ EPO) a sufficient amount of SiH functions to allow crosslinking of the oligomer during the subsequent crosslinking step.

In a 100 ml flask, 1.83 g of AGE are mixed with 50 ml of toluene and degassed under argon for 15 minutes.

Then, 35 mg of Pt / C catalyst are added and mixed with the solution under argon for 15 minutes. 5.06 g of the SiOL ₂ oligomer are added.

The mixture obtained is heated with stirring at 80 ° C for 4 hours. Then, the mixture is diluted in toluene and filtered on a porous 45 μm filter so as to remove all the platinum-based catalyst.

The toluene is then evaporated. The oligomer obtained is dried under vacuum (10 ^" mm Hg) so as to remove any possible trace of AGE. A colorless liquid is obtained.

The characteristics of the SiOL ₂ EPO oligomer are as follows:

Epoxidized oligomers with different contents of epoxy functions are prepared by following the same procedure as above but with the reagents in the following amounts:

Synthesis of SiOL ₃ EPO

The H ₂ PtCl ₆ catalyst is used in place of the Pt / C catalyst. The procedure is unchanged, except that the filtration is not carried out.

The characteristics of the SiOL ₃ EPO epoxy oligomer obtained are:

Synthesis of Si01 ₄ EPO

The characteristics of the epoxidized oligomer are as follows

IA.2 - Functionalization of a siloxane oligomer SiOLs by grafting vinylbenzyl chloride.

FSiOLV

In a 100 ml flask, 1.98 g (12.9 mmol) of vinyl benzyl chloride (VBC) are mixed with 2 ml of toluene and degassed under argon for 15 minutes.

Then, 5 mg of Pt / C (10 ^"4 eq) are added and mixed with the solution under argon for 15 minutes.

Then 5 g of SiOL ₃ are added.

The reaction is carried out at 80 ° C for 3 hours.

Then the mixture is diluted in toluene and filtered through a porous 45 μm PTFE filter to remove the catalyst.

The toluene is then evaporated. The remaining polymer is then dried under vacuum so as to eliminate any possible trace of BCV.

A whitish liquid is obtained.

The oligomer obtained has the following characteristics:

IB - Preparation of functionalized silicone lenses

IB.l - Preparation of silicone lenses containing epoxy groups:

siloxane olihgomer CH ₂ = CH ₂ pendant

(RTV141A) crosslinked silicone with pendant epoxy groups

The epoxidized oligomer SiOL ₄ EPO, the synthesis of which was described above, and the RTV 141 A resin from Rhône Poulenc are mixed in

[SiH] proportions such that the molar ratio = 1.2.

[If - vinyl] The two components are mixed with mechanical stirring for 5 minutes.

Then, the mixture is degassed under vacuum and poured into polyamide molds. A new degassing is carried out. Crosslinking is carried out by heating for 2 hours at 120 ° C.

IB.2 - Preparation of silicone lenses containing groups

FSiOLV

siloxane oligomer with pendant vinyl groups (RTV141A)

Silicone with chlorobenzyl groups

Two polymerizable mixtures are prepared:

- Mix 1:

1 g of RTVA resin and 0.1066 g of FSiOLV oligomer previously synthesized are mixed.

The molar ratio [SiH] of mixture 1 has the value 1.2.

[If - vinyl] - Mixture 2: lg of RTVA resin and 0.1066 g of FSiOLV oligomer are mixed. The molar ratio - - of mixture 2 has the value 2.4.

[If - vinyl]

Each of mixtures 1 and 2 is homogenized using a mechanical stirrer, degassed and placed in molds, either in polypropylene or in polyamide.

The mixtures are degassed again. Crosslinking is carried out by heating for 2 hours at

120 ° C.

TRACK 1: GRAFTING

Two ways have been implemented:

A) Grafting of a zwitterionic oligomer, in particular of a sulfobetaine oligomer (or sulfobetaine telomer), on the surface of a siloxane material, comprising reactive functions, in particular epoxy or chloromé.thylstyène. B) Grafting of a photopolymerization initiator by nucleophilic substitution onto a siloxane material, then contacting one or more zwitterionic monomers, such as sulfobetaine monomers carrying reactive functions, with the surface of the siloxane material comprising the grafted initiator , then polymerization.

TRACK A

Grafting of monomeric or telomeric derivatives. General scheme of synthesis, for functionalized epoxy lenses.

n = 1 monomeric derivative n> 1 telomeric derivative

Grafted polymer

Preparation of a monomeric derivative of sulfobetaine SPP

hilum

Preparation of telomeres

telomere

telomere

(SVP) Preparation of a monomeric sulfobetaine derivative of SPP

In a three-necked flask fitted with a dropping funnel and a magnetic stirrer, an equivalent of cysteamine (1.3344 g) dissolved in 10 ml of ultrapure water is added.

5 g of SPP from RASCHIG and 40 ml of ultrapure water are introduced into the ampoule.

The contents of the ampoule are added at room temperature.

The mixture is heated and stirred at 70 ° C for 75 hours.

The final product is lyophilized (CH 006/03).

Synthesis of zwitterionic telomeres

cysteamine

SPP

initiator

General procedure

The N, N-dimethyl-N-methacryl-amidopropyl-N-3-sulfopropyl-ammonium-betaine (SPP from the company Roschig) is dissolved in ultrapure water or methanol P.A. (5-7% by weight).

Variable amounts of cysteamine are then added (0.01 molar equivalent - 0.1 molar equivalent relative to the amount of SPP), in the presence of 5% molar as initiator.

The mixture obtained is then degassed under a stream of argon for 45 minutes, then heated for 24 to 70 hours at a temperature varying from 65 to 80 ° C. The mixture is then lyophilized.

Preparation of telomeric sulfobetaines with acidic grouping: The following two telomeric sulfobetaines are prepared

The polymerization initiator is ACVA (4,4'-azobis- (4-cyanovaleric acid)). The conditions are as follows:

Preparation of a third telomeric sulfobetaine with an acid group.

the polymerization initiator is ACVA. The preparation conditions are:

The silicone lens prepared in IB.l is grafted by zwitterionic telomeres according to the protocols in the table below:

UP: ultrapure (a): entry) (r): exit) Contact angles (h): hysteresis)

(5)

CF ₃ COO ^" CF ₃ C00 ^"

photoinitiator

telomere

(10)

(14)

TRACK B

water K ₂ C0 ₃

initiator

- Synthesis of the photoinitiator

1) Summary of:

Cl CN CN Cl

-CH CH ₂ : N- ^_ CH ₂ CH ₂ C

CH, CH,

In a three-necked 250 ml flask, dried and equipped with a magnetic stirrer, 100 ml of benzene are added, then 10 g of 4,4'-azobis-4-cyanopentanoic acid (C ₁₂ Hι ₆ 0 ₄ , 3.568 x 10 ^" mole).

The flask is immersed in an ice bath and cooled. The mixture is treated with 20 g of PCI ₅ .

Stirring is continued for 45 minutes, while cooling in the ice bath, then the reaction is continued at room temperature for 1 hour 30 minutes.

The solution is concentrated by vacuum drawing until a pasty white solid is obtained.

The phosphate oxychloride is evacuated with ether / pentane portions (1: 3). The solid is purified by dissolution in methylene chloride followed by precipitation in pentane.

After drying under vacuum, 10.15 g of white solid are obtained. The yield is 90%.

2) Synthesis of

0.5 g of piperazine (1 equivalent, 5.8 10 ^"3 mole) and 0.2554 g of NaOH (1 , 1 equivalent, 6.38 x 10 ^"3 moles) in a mixture of 10 ml of tert-butanol and 15 ml of water.

In the vial, 1.265 g of Boc ₂ 0 (1 equivalent, 5.8 x 10-3 mole) are poured. The contents of the ampoule are then introduced dropwise into the reaction mixture.

The mixture is stirred at room temperature for 17 hours. The white precipitate obtained (protected piperazine diBoc) is separated by filtration and the filtrate is evaporated. After evaporation, dichloromethane is added and a white precipitate appears.

After filtration and concentration of the filtrate, the product obtained is collected. Small amounts of impurities are removed by column chromatography with a CH ^ C ^ / acetone mixture (5/5). 0.32 g of white solid are obtained.

Yield: 30%

3) Synthesis of

In a 10 ml dry flask, equipped with a magnetic stirrer and an addition funnel, 0.1 g of

(2 equivalents 5.37 x 10 mole)

and 43.4 μl pyridine (2 equivalents, 0.0424 g) are dissolved in 2 ml of dry dichloromethane.

Into the ampoule, pour 0.0583 g of

(1 equivalent 2.69 x 10 ^"4 mole) with 1 ml of dry dichloromethane.

The contents of the ampoule are then added dropwise at 0 ° C. The mixture is stirred at room temperature for 17 hours. The solution is then washed with water and with an IM HCl solution. The organic phase recovered is concentrated at room temperature.

0.11 g of white solid is obtained after purification by column chromotography with a CL ^ C ^ / acetone mixture. The yield is 65%.

4) Summary of:

In a 10 ml flask equipped with a magnetic stirrer and an addition funnel, 0.08 g of the compound obtained in step 3 (1 equivalent, 1.2987 x 10 ^'4 mole) is dissolved in 2 , 5 ml of CF ₃ COOH. The mixture is stirred at room temperature for 3 hours. The solution is then concentrated at room temperature and the remaining mixture is washed with chloroform.

- Grafting and light-curing

An epoxidized silicone lens (obtained as described in Example 1 of patent EP 317,377) is placed in a container containing 5 ml of a solution of the photoinitiator (1% by weight) in ultrapure water and 0.0107 g of K ₂ C0 ₃ .

The lens is stirred with an Edmurd Bϋhler shaker (model KL-2, VIBRAX) for 17 hours at 20 ° C, in the absence of light, then removed with tweezers and rinsed 4 times (12 minutes with ultrapure water).

The sample kept in water is then analyzed by UV spectrometry.

Structure:

Light curing:

The lens is placed in a container containing a magnetic stirrer and 2.5 ml of a solution of 0.5 g of SPP (N, N dimethyl-N- methacrylamidopropyl-N-3-sulfopropyl-ammonium-betaine (from the company RASCHIG) in 3.5 ml of ultrapure water. The solution is degassed under a stream of argon for 1 hour, then irradiated (with lamps at 235 nm) for 1 hour with stirring. The lens is then removed and rinsed 4 times (12 minutes) in ultrapure water.

The samples are kept in water.

They are analyzed by UV spectrometry.

The wettability characteristics are measured (see previous general table).

The sample obtained is transparent. Measurement of contact angles This measurement method is shown diagrammatically in Figure 3.

The test pieces of polymer material for the measurement of contact angles are strips cut from molded discs (diameter 15 mm, thickness 0.2 mm). The dynamic measurement of the contact angles is carried out as follows: The test pieces are soaked in about 10 ml of water.

The test piece is fixed to an electrobalance and the container containing the water is raised and lowered by means of a motor to immerse the test piece. The speed of ascent and descent is 0.1 mm / second. During the ascent and descent, the force applied is graphically recorded as a function of the immersion depth. The contact angles of entry (h) a (rise) and exit (h) r (fall) are calculated using the relation COS (H) =

(γL) (P) where γL is the surface tension of the water;

P is the perimeter of the sample; and Δω the force variation during immersion.

When entering the test pieces, the entry contact angle θa is measured and when removing the test pieces the exit contact angle θr. These measurements are made at 21 ° C.

Excellent hydrophilicity of the material corresponds to an entry angle of 100 to 70 ° C, preferably from 90 to 70 ° C and an exit angle of 20 to 50 degrees. Hysteresis corresponds to the difference between the angles of entry and exit of the same test tube. This value must be less than 50 degrees at least.

Claims

1. Hydrophilic polymer material characterized in that it comprises a matrix of crosslinked polyorganoxiloxanes comprising substituents linked to silicon atoms carrying one or more zwitterionic groups.

2. Polymeric material according to claim 1, characterized in that the polydiorganosiloxanes are chosen from polydialkylsiloxanes, polyalkylsiloxanes, and polydialkyl alkyl aryl siloxanes.

3. Polymeric material according to claim 1, characterized in that the polyorganosiloxanes are chosen from polydimethylsiloxanes, polymethylphenylsiloxanes and polydimethyl methyl phenyl siloxanes.

4. Polymeric material according to any one of claims 1 to 3 characterized in that the zwitterionic groups are sulfobetaine groups.

5. Polymeric material according to any one of claims 1 to 3, characterized in that the zwitterionic groups correspond to the formula:

in which :

- R ⁶ represents an alkylene, cycloalkylene, aromatic group, optionally containing in its chain one or more heteroatoms;

7 o

- R and R represent, independently of each other, a hydrogen atom, a CH ₂ -R ^{10 group} in which R ¹⁰ may be a hydrogen atom, an alkyl radical, a CH ₂ -R group ⁿ in which R "is a substituent optionally comprising heteroatoms, a group

• 7 R phenyl provided that at least one of R or R is an atom hydrogen, or R ⁷ and R ⁸ , identical or different, may constitute a ring optionally comprising one or more additional heteroatoms;

- R ⁹ represents an alkylene or substituted alkylene group optionally comprising one or more heteroatoms; and

- R ⁷ and R ⁹ can, jointly, form a ring or a polycyclic structure optionally comprising one or more heteroatoms.

6. Material according to claim 5, characterized in that the zwitterionic groups are chosen from the groups of formula:

-CH ₂ CH ₂ - + CH ₂ -JN ⁺ f J ~ Cπ ₂ Cπ ₂ - SO ₃

H -CH ₂ - CH ₂ - + - CH ₂ J ⁺ hCH ₂ -SO,

CH ₂ CH CH ₂ CH ₂ - NH ⁺ CH ₂ CH ₂ CH ₂ C00

CH, CH,

CH ₂ CH CH ₂ CH ₂ - NH ₂ - CH ₂ CH ₂ CH ₂ COO ^"

CH,

CH ₂ CH CH ₂ 0 P OCH ₂ CH ₂ N ⁺ (CH ₃ ) ₃

CH,

where n is an integer from 1 to 20, x is an integer from 2 to 10 and p is an integer from 1 to 20.

7. A method of manufacturing a hydrophilic polymer material comprising a matrix of crosslinked polyorganosiloxanes comprising substituents with zwitterionic groups linked to silicon atoms and carrying at least one zwitterionic group, characterized in that it comprises: the grafting onto at least one polyhydrogenoorganosiloxane of substituents carrying one or more zwitterionic groups or groups precursors of zwitterionic groups by hydrosilylation reaction of part of the hydrogenosilyl units of the polyhydrogenoorganosiloxane with a reactive compound carrying at least one group zwitterionic or group precursor zwitterionic;

- where appropriate, the transformation of the precursor groups into zwitterionic groups; and

- crosslinking of the polyhydrogenoorganosiloxane (s).

8. Method according to claim 7, characterized in that the crosslinking of the polyhydrogenoorganosiloxanes is carried out before the grafting of the substituents to zwitterionic groups or precursors of zwitterionic groups.

9. Method according to claim 7 or 8, characterized in that the polyhydrogenoorganosiloxanes are polyhydrogenomethyldimethyl-siloxanes and / or polyhydrogenomethylsiloxanes.

10. Method according to any one of claims 7 to 9, characterized in that the crosslinking of the polyhydrogenoorganosiloxanes is carried out by the addition reaction SiH-olefin of a crosslinking agent comprising terminal olefinic functions.

11. Method according to claim 10, characterized in that the crosslinking agent is a siloxane oligomer with vinyl end groups.

12. Method according to claim 11, characterized in that the oligomer is an oligomer of dimethylsiloxane.

13. Method according to any one of claims 7 to 12, characterized in that the reactive compound comprising at least one zwitterionic group or precursor of zwitterionic group is a compound comprising a reactive olefinic function.

14. Method according to claim 13, characterized in that the reactive compound is chosen from sulfobetaines comprising a reactive olefinic function.

15. Method according to any one of claims 7 to 12, characterized in that the reactive compound comprising at least one precursor group of zwitterionic group is a reactive compound with precursor group of sulfobetaine group of formula:

where R 'is a divalent organic residue and R "represents hydrogen or an alkyl group, preferably methyl, and the precursor groups are transformed into sulfobetaine groups by reaction with a γ-alkane sultone, preferably γ-propane sultone.

16. Method for manufacturing a hydrophilic polymeric material comprising a matrix of crosslinked polyorganosiloxanes comprising substituents with zwitterionic groups linked to silicon atoms and carrying at least one zwitterionic group, characterized in that it comprises:

crosslinking of a composition comprising at least one polyorganosiloxane oligomer with SiH functions and at least one polyorganosiloxane oligomer with Si-vinyl function, at least one of the two oligomers carrying sites on which are capable of being grafted zwitterionic compounds or precursors thereof;

- grafting of zwitterionic compounds or their precursors; and

- if necessary, the transformation of the precursors into zwitterions.

17. A method of manufacturing a hydrophilic polymeric material comprising a matrix of crosslinked polyorganosiloxanes comprising substituents with zwitterionic groups linked to silicon atoms and carrying at least one zwitterionic group, characterized in that it comprises: - the reaction of at least one siloxane monomer with SiH functions and at least one siloxane monomer with Si-vinyl functions in the presence of a cyclic siloxane monomer carrying at least one zwitterionic group or precursor thereof; and - if necessary, the conversion of the precursor (s) into zwitterion (s).

18. Optical article characterized in that it comprises a basic structure made of the material according to any one of claims 1 to 6.

19. Optical article characterized in that it is coated with a surface layer made of the material according to any one of claims 1 to 6.

20. Optical article according to claim 18 or 19, characterized in that the article is a contact lens.