WO1988005060A1

WO1988005060A1 - Wettable, hydrophilic, soft and oxygen permeable copolymer compositions

Info

Publication number: WO1988005060A1
Application number: PCT/US1988/000006
Authority: WO
Inventors: Sing-Hsiung Chang; Mei Zyh Chang
Original assignee: Chang Sing Hsiung; Mei Zyh Chang
Priority date: 1987-01-07
Filing date: 1988-01-05
Publication date: 1988-07-14
Also published as: EP0296220A4; EP0296220A1; AU1156688A; JPH01503072A

Abstract

A copolymer, specially adapted for use as certain medical devices such as contact lens, eye bandage, artificial skin for burn or wound dressing, of comonomers comprising: (A), 1 to 85 wt.% of at least one amide acrylic; (B), 1 to 35 wt.% of at least one vinyl carboxylic acid; (C), 1 to 90 wt.% of at least one compolymerizable vinylic organosiloxane; and optionally, (D), 1 to 90 wt.% of at least one copolymerizable vinylic fluorinated monomer; and further optionally, (E), 1 to 80 wt.% of at least one acrylic alkanol.

Description

WETTABLE, HYDROPHILIC, SOFT AND OXYGEN PERMEABLE COPOLYMER COMPOSITIONS

FIELD OF THE INVENTION

This invention relates to novel copoly er composition, and more particularly to an increased oxygen permeable, soft, hydrophilic, tear wettable, dehydration resistant, deposition resistant and stable copolymer for contact lens, eye bandage or artificial skin for burn or wound dressing.

BACKGROUND OF THE INVENTION

The basic requirement for polymeric materials in some areas of medical application are that they be hydrophilic, soft, oxygen permeable, body fluid wettable, dehydration and deposition resistable and stable. The prior art teaches the use of many different polymer¬ ic materials in medical areas such as in contact lens, eye bandage, artificial membranes e.g., surgical and burn dressings, membranes for an artificial lung machine. Although such polymers possess certain desirable properties for their specific medical use, they suffer from other undesirable characeristics which reduce their utility.

In contact lens areas, there are many required features to make a contact lens successful, especially for the most desired extended wear use. In order to brief the merits and the shortcomings of - the material developed in each phase of the contact lens history, each of the most required features of a desi red contact lens i s desi gnated a number and l i sted bel ow:

1. oxygen permeability;

2. softness;

3. hydrophilicity;

4. stability;

5. long term functional (body fluid or tear) wettability;

6. dehydration resistance; and

7. deposition resistance

The development of a plastic material for contact lens use has come a long way. Earliest, the- ard plastic material , polymethylmethacrylate (PMMA)came in use. Generally this hard lens provides the good features of 4 and 6 list above, but has the major shortcomings in the features 1, 2, 3, 5 and 7. Later the hydrogel lens, poly 2-hydroethyl methacrylate (Poly HEMA) related soft lens became popular, because generally it provides the good features of 2, 3, 4, 5, 6 and 7, but it still has the shortcoming in the above feature 1, oxygen permeability. Insufficience of oxygen supply to the cornea! could have serious detrimental effect to the cornea!, such as resulting in cornea! ulcers, infection and thickening. Thus, recently patients started to pay attention to the hard gas permeable lens (HGP) primarily made of two major types of HGP lens material - acrylic sillcone and acrylic fluorosilicone. Generally HGP lens provides the good features of 1 , 4 and 6, but it still suffer from the poor features- of 2, 3, 5 and 7. As a result of the defect, a lot of incidents of cornea! abrasion, cornea! warpage and discomfort occurred. So the lens practi¬ tioners are now looking forward to having a soft gas permeable, SGP-, lens which could provide all the desired features listed above.

There are already several inventions of SGP lens taught in the art, e.g., the CHANG patent, U.S.P. #4,182,822 and #4,343,927; the Tanaka patent, U.S.P. #4,139,513 and the LeBoeuf patent, U.S.P. #4,246,389. ATthough the lenses made of these patent materials provide the good features of high oxygen permeability, softness and hydrophilicity, they fail to over¬ come the relatively poor quality in the features of 5, 6 and/or 7 listed above. Thus, the SGP lens is still not available.

The material described in the CHANG patents are highly oxygen permeable, soft and hydrophilic. But surprisingly we discovered that the material just being highly hydrophilic is not good enough for a long term contact lens use. The lens made thereof is highly soft and hydrophilic, but surprisingly is relatively poor in the long term functional (tear) wettabi¬ lity, dehydration resistance and/or deposition resistance. Although the lens would be excellent for certain daily wear use, it is highly not suitable for the extended wear use. The material described in the Tanaka or LeBoeuf patent would have a similar defect.

Apparently, to have a breakthrough in providing such a copolymer having all the desired features listed above and further lifting the state of art into a new era is extremely desirable and useful for human being who need have vision correction. The patients will enjoy the benefits of contact lens and not suffer from it the differnt shortcomings. In search for such a copolymer, an intensive effort has been made in last 12 years, now we have discovered such a new copolymer system.

The brief of each phase of the lens development described above is summa¬ rized in Table I. The patents, U.S.P. #4,182,822 and 4,343,927 are cited herein as the references of this specification.

Although this invention is primarily directed toward contact lenses, the unique properties of the invented material is also highly desirable in the areas of medical applications, such as eye bandage for drug control release or protective devices for cornea injury or disease, bandages for wound treatment or artificial skin as burn dressing, artificial lung membrane for lung machine .

TABLE I

Summary of the General Features of Merits and Shortcomings of the Lenses^ the Materials or the Patented Compositions in Different Phases of the Contact Lens Development

Phase Lens, Material or patented Merit or Shortcoming or Composition Item Taught Item not Taught

Hard, PMMA 4, 6 1, 2, 3, 5, 7

II Soft, Hydrogel, Poly HEMA 2, 3, 4, 5,

6, 7

III Hard Gas Permeable

1. Acrylic Si1 icone 1, 4, 6 2, 3, 5, 7

2. Acrylic Fluorosilicone

IV Soft Gas Permeable

The Patent of Chang, Tanaka 1, 2, 3, 4 5, 6, 7 or LeBoeuf

The Present Invention 1, 2, 3, 4 5, 6, 7

The number shown in the Table is designated to each desired feature for a successful contact lens: 1 _t oxygen permeability; 2, softness; 3, hydro¬ philicity; 4, stability; 5, long term tear wettability; 6, dehydration resistance; and 7, deposition resistance.

PMMA is poly methyl methacrylate; Poly HEMA is poly 2-hydroxyethyl metha¬ crylate. ^'Acrylic silicone such as those described in U.S.P. # 4,152,508; 3,808,178 Acrylic fluorosilicone such as those described in Japan Kokai Tokkyo Koho JP 61,126,052 (Chem. Abstract: 105:191777c).

The Chang patent referred to U.S.P. # 4,182,822 and # 4,343,927; the Tanaka patent to U. S. P. # 4,139,513 and the LeBoeuf patent to U.S.P. # 4,246,389. DISCLOSURE OF THE INVENTION

This invention relates to a new copolymer specially adapted for making certain medical devices. The object of this invention is to provide a new and useful copolymer having substantially increased not only oxygen permeability, softness and hydrophilicity but also long term body fluid (tear) wettability, dehydration resistance and deposition resistance for making contact lens, eye bandage, artificial skin or artificial membranes for lung machine.

The novel copolymers disclosed are prepared by copolymerizing a comonomer composition comprising:

(A), 1 to 85, preferably 15 to 65 and most preferably 25 to 65 wt. (weight)

% of at least one amide acrylic; (B), 1 to 35, preferably 1 to 20 and most preferably 1 to 15, wt.% of at least one vinyl carboxylic acid; (C), 1 to 90, preferably 5 to 75 and most preferably 10 to 65, wt.% of at least one copolymerizable vinylic organosiloxane; and optionally, (D), 1 to 90, preferably 1 to 65 and most preferably 10 to 65 wt.% of "at least one copolymerizable vinylic fluorinated monomer; and further optionally, (E), 1 to 80, preferably 1 to 65 and most preferably 20 to 50, wt.% of at least one acrylic alkanol.

Note that in order to avoid redundance, wherever "acrylic" is referred to in this specification and Claim, "methacrylic" is included and vice versa, such as when acrylic acid is referred to, methacrylic acid is also included.

Amide acrylic that is suitable for the practice of this invention has the general structure:

PVG - C0NR₂R₃ wherein PVG is a copolymerizable vinylic group known in the art, preferably selected from a group consisting essentially of vinyl (CH~=CR..-), acrylato (CH =CR₁C00-R₄-), acryla ido (CH ₂=CR₁ CONR- -R _g-) ; wherein R is selected from a group of H, -CH₂C00R₇ and C_j-C - alkyl; R , R, , R ., R_ , R - and

R₇ , which can be the same or different, substituted or not substituted, are selected from a group consisting essentially of H, C^ -C- alkyl, phenyl and cyclohexyl. Preferably, amide acrylic is a N,N-dialkyl methacrylamide and most preferably^ a N,N-dimethylmethacrylamide. PVG can also be a styrenyl (CH_j,=CH-CgH_-) . Amide acrylic selected is preferably in liquid form at ambient condition.

Vinyl carboxylic acid (hereafter referred to as VCA) that can be used in the practice of this invention has the general structure: PVG'-(A)_n wherein PVG¹, which may be the same as or different from the above PVG, has the same scope of definition as specified above except PVG' here can also be an acryloxy (CH₂=CR^C00-), wherein A is an acidic hydrogen group selected from a group of -H and -COOH; n is an integer of at least one, i.e., VCA can contain more than one A group. Thus, VCA comprises at least a carboxylic acid group (-COOH) and a polymerizable vinylic prefer¬ ably selected from a group of acryloxy and styrenyl. Preferably, VCA is selected from a group consisting essentially of: methacrylic acid, acrylic acid, itaconic acid, methacryloxybenzoic acid, methacryloxyethanoic acid, and vinylic benzoic acid. VCA selected is preferably in_l_iquid form at ambient condition. VCA can be used singly or in admixture. When VCA such as methacrylic acid is used, its amount in the composition is preferably kept below 20%, more preferably below 15% and most preferably below 10 wt.%.

Copolymerizable vinylic organosiloxane (hereafter referred to as COS) that can be used in the practice of this invention is liquid and comprises a polysiloxanyl , one polymerizable acrylic and one chain connecting with these two groups. The structures of the essential constituent units of such methacryloxy -X- polysiloxane are shown below: M, CH₂=CR₁C0₂-X-(CH₃)_aSi0₃__a and

N, (CH₃)_bSi0^

2 wherein X is selected from a group consisting of alkyl, alkenyl, phenyl and cyclohexyl, substituted or not substituted; preferably X is an alkylene, -(CH₂)_n- wherein n is an integer of at least one, prefer¬ ably of from 1 to 10_t a is an integer of 0 to 2 inclusive and b is an integer of from 0 to 3 inclusive; each COS includes at least one M and the molar ratio of N to M is at least one, preferably selcected from a range of one to 25.

Obviously, the desired COS can easily be modified into other forms without departing from the essence of this invention, such as in the polymerizable group and the linkage group. Thus, the general structures of the essen¬ tial constituents of the useful COS are disclosed below:

M', P - chain - R'aSiO J,—a. and

^~

wherein P is a polymerizable vinylic group, such as viny, acrylamido, styrenyl, methacryloxy; chain is a chain of chemical bonds which may be linear or branched, however, the chain length is at least one chemical bond; wherein each COS include!- at least one M' and the value of the molar ratio of N¹ to M' is at least one; wherein R' and R" are selected from a group consisting of H, substituted and nonsubstituted alkyl, alkenyl, cyclohexyl and phenyl, such as, -CH₃ , -CF₂CF₃ , -CH₂C00R, -CH₂CH₂C0N- (CH,)₂, -CH₂0H etc-; preferably, said chain contains 1 to 12 chemical bonds.

Note that the term of molar ratio is not used herein as based upon the actual molecular weight of the copolymer per se, but rather as based upon the molecular weight of the unit or average molecular weight of the units which are present in such copolymer, as is the common polymer practice.

The structure of COS as defined above can be illustrated below:

H₂C =C(CH₃)C0₂-(CH₂)₃-Sj[-0-Si(CH₃)₂-0-Si(CH₃)₃ ]-

wherein this COS contains one M group with a = 0 and six N groups with 3 of them having b = 2 and the other three having b = 3; the molar ratio of N to M is 6 to 1.

The procedures to prepare the desired COS is well known in the art, e.g., those described in U.S.P. #4,120,570; 4,153,641; 3,808,178; 4,343,927. Representative examples of COS includes:

1. pentamethyldisiloxanyl methyl methacrylate,

2. r-methacryloxypropyl tris(pentamethyldisiloxanyl)silane,

3. -methacryloxypropyl tris(trimethylsiloxanyl)silane,

4. methacryloxymethyl heptamethylcyclotetrasiloxane,

5. trimethylsilyl methyl methacrylate,

6. reaction products of r-methacryloxypropyl tri ethoxysilane with trimethylacetoxysilane, pentamethylacetoxydisiloxane and/or heptamethyl acetoxytrisiloxane catalyzed by an acid (Based on GC analysis, the product contains at least one COS having one M group and one COS having two M groups..)

Copolymerizable vinylic fluorinated monomer (hereinafter referred to as CVFM) that can be used in the practice of this invention has the general structure: PVG"-Y wherein PVG" is selected from a group consisting essen¬ tially of vinyl, methacryloxy, methacrylamido and styrenyl, preferably selected from a methacryloxy; Y is selected from a group consisting of fluorinated alkyl, cyclohexyl and phenyl, substituted or not substituted. The fluorination can be carried out by the techniques knownin the art. The preferred CVFM's are such as those described in "U.S.P. #3,950,315 and 3,808,179; Japan Kokai Tokkyo Koho JP^" #61,109,756 (Chem. Abract: 105:232482y); JP #59,214,822 (Chem. Abstract: 102:226074p). Representative examples of CVFM are:

1. 1 ,1-dihydrofluoropropyl methacrylate,

2. 1 ,1 ,18-trihydrofluorooctadecanyl methacrylate,

3. l,l-bis(pentafluorophenyl)methyl methacrylate

4. fluorostyrene,

5. trifluoroethyl methacrylate,

6. 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoropentyl methacrylate,^"

7. 2-hydroxy-4,4,5,5,6,6,7,7,8,8,9,9,10,11,11,11-hexadecafluoro- 10-trifluoromethylundecyl methacrylate

8. 2,2,3,3,4,4,5,5-octafluoropentyl methacrylate Preferably, alkyl is selected from C, to C₂₀

Acrylic alkanol that can be used in this invention is selected from a group consisting of acryloxy alkanol and acrylamido alkanol, wherein alkanol is an alcohol of C-_] -C . Preferably acrylic alkanol is selected from a group of 2-acryloxyethaol , 3-acryloxypropanol and 3-acryloxy, 1,2-propan-diol . The novel body fluid or tear wetting system of this invention is to modify the copolymer rendering not only highly oxygen permeable, soft and hydro¬ philic but also stable, long term body fluid wettable, dehydration resis¬ tant and deposition resistant. To incorporate VCA into the copolymer described in the prior art U.S.P. #4,343,927 can substantially improve the body fluid or tear wettability of the material or lens made thereof. To further incorporate fluorinated acrylate and acrylic alkanol of this invention into such copolymer, the resistance to protein deposition is substantially increased. To incorporate acrylic alkanol into the copolymer can substantially improve the highly desired tintability of the lens. Optionally, some of the other physical properties, such as strength, optical, hardness, surface property of the copolymer in this invention can be modified, if desired, by copolymerizing the composition with (F), 1 to 30 wt.% of at least one copolymerizable property modifier which is selected from _a group consisting of C. -C_2Qalkyl methacrylate, styrene, acrylonitrile and methacrylamide.

The rigidity of the copolymer in this invention can also be improved, if desired, by incorporating into the material with (G), 0.1 to 30, preferably 0.1 to 10, wt.% of at least one crosslinking monomer known in the art. The cross!inker contains at least two polymerizable vinylic or acrylic groups. Representatives of crosslinking monomers which are suitable for the practice of this invention are polyol dimethacr late or a polyo! methacrylic ester of higher functionality, for example, mono-, di-, tri-, or tetraethylene glycol dimeth cr late, butylene glycol dimethacry- late, neopentyl diacrylate and pentaerythritol triacrylate or tetracrylate and the like. The COS described above containing at least two M groups can also be used as crosslinking monomers as described here.

The process to prepare the desired comonomers and to prepare the copolymer of this invention is well known in the art, especially described in the specifications and the examples of the references cited previously. The technique to make the contact lens from the composition of this inven¬ tion is also well known in the art. For example, a copolymer of comonomer mixture of this invention can be prepared by the same process as detailed in Example of U.S.P. #4,343,927 or 4,182,822.

The novel copolymer system of this invention can provide the desired features of a successful contact lens. Not only the lens has substantial- ly increased oxygen permeability, softness and hydrophilicity but also stability, long term body fluid or tear wettability, dehydration resistance and deposition resistance. Thus, the wearing comfort is substantially improved. The lens can continuously be worn for a long period of time.

The copolymer can be fabricated into soft gas permeable ( SGP ) lens.

Preferably the water content of this SGP lens is controlled between 30 and 75 wt.% after hydration. The water content can be controlled by adjusting the amount of the comonomers (A) and (B) listed above. If desired, this novel . copolymer can also be prepared for the use of a hard gas permeable (HGP) lens. Preferably, the water content of the HGP lens of this invention is controlled between 1 and 8 wt.% by controlling the amount of comonomer (A) and (B) listed above, and by adding certain amount of crosslinking monomer. Due to the hydrophilic and wettable nature of the HGP lens of this invention, the softness of the lens surface is substantially increased and so are the long term tear wettability, dehydration resistance and deposition resistance. Thus, the wearing comfort and wearing period of the lens is substantially improved. ^*

The unique properties of the invented material is also highly desirable in certain areas of medical applications, such as eye bandage for drug control release or protective devices for cornea injury or disease; bandage for wound treatment or artificial skin as burn dressing, artificial lung membrane etc. In these areas of application, mostly the invented copolymer is fabricated into thin film or membranes by the technology known in the art such as a thin film casting from the liquid comonomers. Thus, such use of the invented copolymer is also included in the embodiment of this invention. In contact lens use, the transparent copolymer is required; otherwise, it is not the case.

BEST MODE FOR CARRYING OUT THE INVENTION

EXAMPLE 1

This example illustrates the general procedure to prepare the copolymer of this invention.

The copolymer of 14 (wt.) % NNDMA (N,N-dimethylacrylamide) , 6% MA (metha¬ crylic acid), 14% TMPT (1,1 ,1-trimethylol propane trimethacrylate) and 66% MPTS (^-methacryloxypropyl tris(trimethylsiloxy)silane prepared by following Example 15 of U.S.P.#3,808,178 except catalyzed by a cone. HCl and reacted for ca. 6 hours) was prepared.

First, put each ingredient according to the composition with 0.2% t- butyl peroxypyvalate into an inert plastic tube. The composition was then de-oxygenated by nitrogen for 10 minutes. The tube was then placed in a 45 °C water bath for 4 hours, followed by placing the tube in a 95° C oven for 4 hours. The translucent rod was then cut into buttons and post cured at 120 °C under high vacuum for 6 hours. The buttons were cool gradually. The lens made of this copolymer is transparent. The oxygen permeability, DK units of this lens is about 60 (cm /sec-ml- 0₂ /mlxmmHg) _t as compared to the DK unit poly HEMA with 38% water content at ca. 8 and that of PMMA hard lens at less than one. The lens can absorb ca. 4% water as compared to ca. 0.5% of the PMMA lens. The desired hydro¬ philicity and high oxygen permeability of the lens increase the soft feeling and comfort for a successful extended wear of a contact lens.

EXAMPLE 2

This example illustrates a substantial increase in functional (body fluid or tear) wettability of the copolymer or lens of this invention. It also illustrates that the tear wettability is not only dependent on the hydrophilicity of the material.

The tear wettaility of a contact lens on a human eye can be reflected in the tear breakup time (BUT) ofthe tear film on the lens surface. BUT here is the time visually monitored before the tear film breakup or before a dried spot appearing on the lens surface after an individual eye with the lens is open.

The BUT of the lens made of the above copolymer after fully hydrated in a physiological saline is ca. 2 minutes in a human eye testing. But the BUT of a lens made of the copolymer of 20 (wt.)% NNDMA, 15% TMPT and 65% MPTS as described in the closest prior art, U.S.P. #4,343,927, after fully hydrated, is about 0.5 minute. A substantial increase or in this example about 400% increase of BUT of this inventi.on over the closest prior art is highly desirable for a successful extended wear of a contact lens. Both lenses have similar water content or hydrophilici- ty but the tear wettability or BUT is dramatically different. So this example also illustrates that the body fluid or tear wettability of a lens or the copolymer is not only dependent on the hydrophilicity of the material .

EXAMPLE 3

This example further illustrates the novelty of this invention showing the lens is substantially increased in functional (body or tear) wettabili¬ ty, dehydration resistance and deposition resistance.

A lens was made of the composition of 50 (wt.)% NNDMA, 5% MA, 4% MAA (methacrylamide) and 41% MPTS and 0.1% .TMPT of this invention. After equilibrated in a physiological saline, the lens was subject to a human eye testing. Its BUT is about 2 minutes. The lens could very comfortably be worn for one week continuously on the same tested eye. No tear wettabi¬ lity problem, dehydration problem, deposition problem, stability problem was experienced during wearing or at the end of wearing. But the lens prepared from a similar composition of the above closest prior art having 55% NNDMA, 5% MMA (methyl^' methacrylate) and 40% MPTS after full hydration in a physiological saline is not suitable for an overnight extended wear. The problem likely resulted from the synergetic effect of the relatively poor quality in tear wettability, dehydration resistance and deposition resistance of the lens of the closest prior art.

EXAMPLE 4

This example further illustrates the novelty of this invention substantial¬ ly increasing the lens stability, long term tear wettability, dehydration resistance and deposition resistance.

A lens was made of the composition of 24 (wt,)% NNDMA, 6% MA, 10% EGDM (ethylene glycol dimethacr late) and 60% MPTS of this invention. After saturated in a physiological saline, the lens was subject to a human eye testing. Its BUT is about 2 minutes. The lens could very comfortably be worn for about 20 days continuously. No problem in tear wettability, dehydration resistance and deposition resistance was experienced during the wearing. The lens has substantially increased oxygen permeability, DK unit ca. 53, sofness and hydrophilicity. EXAMPL E 5

A lens was made of the composition of 39 (wt.)% NNDMA, 2.2% MA, 46% MPTS and 12.8% HEMA of this invention. After fully hydrated in a physiolo¬ gical saline, the lens was subject to a human eye testing. It had excel¬ lent BUT and the lens could very comfortable be worn for about 30 days continuously, reflecting the excellency in tear wettability, dehydration resistance and deposition resistance of this invention.

EXAMPLE 6

A thin film (ca. 20-50 micron) cast from a comonomer composition of 50 wt.% of r-methacryloxypropyl, tris(trimethylsiloxy)silane, 10% methacrylic acid, 40% NNDMA and 0.1% TMPT is very oxygen permeable, soft, hydrophilic, body fluid wettable, thus compatible, after hydrated in a physiological saline. The film should be excellent as burn or wound dressing. This film should not only provide the required physiological response but also provide comfort for patient and transparency of the dressing for progress monitoring by attending doctor. This film can also be used as eye protective membrane for corneal injury, disease or drug release-

EXAMPLES 7-26 ^■

Some representative compositions of this invention are shown in Table II and III.

While the invention has been described in connection with preferred embo¬ diments, it is not intended to limit the invention to particular forms set forth, but on the contrary, it is intended to cover such alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. TABLE II. SOME REPRESENTATIVE COMPOSITIONS OF THIS INVENTION

*MN = N,N-dimethylmethacrylamide; NN = N,N-dimethylacrylamide; MA = methacrylic acid; IA = itaconic acid; . HM = HEMA; S1 = ^r-methacryloxypropyl tris(pentamethyldisiloxanyl)silane; S2 = trimethylsilyl methylmethacrylate S3 = reaction product of ^-methacryloxypropyl trimethoxysilane with trimethylacetoxysilane; S4 = methacryloxyme thyl heptamethylcyclotetrasiloxane; S5 = pentamethyldisiloxanylmethyl methacrylate; FPM = 1,1-dihydrofluoroprop methacrylate; MMA = methyl methacrylate; St. = styrene; EGDM

lene glycol dimethacrylate; TMPT, as defined in specification.

TABLE III. REPRESENTATIVE COMPOSITIONS CONTAINING DIFFERENT FLUORINATED MONOMERS AND ACRYLOXY ALKANOLS

Example

# MN MA ^S1 ^F1 ^F2 ^F3 ^F4 HP HG MMA TPMT

21 10 6 62 5 13 4

22 10 6 57 10 13 4

23 10 6 52 15 13 4

24 10 6 47 . 20 13 4

25 48.5 2.5 30 4 5 10 0.2

26 48.5 2.5 32 4 3 10 0.2

wherein MN, MA, S. , MMA and TMPT are the same as those used in Table II; R. = fluorostyrene; F = trifluoroethyl methylate; F₃ = 1, l-bis(pentafluorophenyl ) methyl methacrylate; F. = 1, 1, 18-trihydro fluorooctadecanyl methacrylate; HP = 3-methacryloxy propanol ; and HG = 3-methacryloxy, 1,2-propan- diols.

INDUSTRIAL APPLICABILITY

This invented copolymer is extremely desirable and useful for making extended war contact lens for vision correction. The copoly¬ mer should also be highly useful for making eye bandage, artificial skin for burn or wound dressing or artificial membrances for lung machine.

Claims

WHAT IS CLAIMED IS:

1. A coply er of comonomers comprising:

(A), at least one amide acrylic; (B), at least one vinyl carboxylic acid;

(C), at least one methacryloxy -X- polysiloxane having the structures of the essential constituent units below: M, CH₂=C(CH₃)-C0₂-X-(CH₃)_aSi0₃_. and N, (CH₃)_bSiO -f^"

2 wherein X is an alkylene, -(CH₂ ) -, n is an integer of 1 to 10; a is an integer of 0 to 2 inclusive and b is an integer of from 0 to 3 inclusive; wherein all the molecules contain at least one M group and the molar ratio of N to M is at least one; (D), at least one fluorinated alkyl methacrylate; and (E), at least one acrylic alkanol; said copolymer being characterized in that the amount of (A) is select¬ ed from a range of 1 to 85 wt.%, (B) from 1 to 35 wt.%, (C) from 1 to 90 wt.%, (D) from 1 to 90 wt.% and (E) from 1 to 80 wt.%,^' any balance being made up by comonomer(s) (F) and/or (G), wherein (F) is at least one property modifier, a copolymerizable vinylic monomer and (G) is a crosslinking monomer.

2. A contact lens having substantially improved functional wettability, deposition resistance and oxygen permeability prepared from the copoly¬ mer according to claim 1.

3. The copolymer of claim 2, wherein (A) is selected from N,N-dialkyl- methacrylamide and N,N-dialkylacrylamide, wherein alkyl is selected from C_| to C₂; (B) is selected from methacrylic acid, acrylic acid, itaconic acid, methacryloxybenzoic acid, methacryloxyethanoic acid and vinyl benzoic acid; wherein (C) is selected from a group consisting of: a. pentamethyldisiloxanyl methyl methacrylate; b. r-methacryloxypropyl tris(pentamethyldisiloxanyl )silane; c. r-methacryloxypropyl tris(trimethylsiloxanyl )silane; d. methacryloxy ethyl . eptamethylcyclotetrasiloxane; and e. reaction product of r-methacryloxypropyl trimethoxysilane with trimethylacetoxysilane, pentamethylacetoxydisiloxane and/or heptamethylacetoxytrisiloxane; wherein (D), said alkyl is selected from C<_|-C₂g ; and (E) is selected from a group of 2-acryloxyethanol , 3-acryloxypropanol and 3-acryloxy, 1,2-propan-diols; said copolymer being characterized in that the amount of (A) is selected from 15 to 65 wt.%, (B) from I to 20 wt.%, (C) from 5 to 75 wt.%, (D) from 1 to 65 wt.% and (E) from 1 to 65 wt.%.

4. The copolymer of Claim 3, wherein (B) is selected from methacrylic acid and itaconic acid and (E) is a 2-acryloxyethanol; the amount of (A) is from 25 to 65 wt.%, (B) from 1 to 15 wt.%, (C) from 10 to 65 wt.%, (D) from 10 to 65 wt.% and (E) from 20 to 50 wt.%.

5. A soft contact lens made of the copolymer according to Claim 2, wherein the water content of the lens after fully hydrated in a physiological saline is between 30 and 75 wt.%.

6. The copolymer of Claim 2, whrein (C), said X is selected from a group of alkyl, cyclohexyl and phenyl, substituted and non-substituted.

7. The copolymer of Claims 1 to 6, wherein said comonomers comprising (A), (B), (C) and (D).

8. The copolymer of Claims 1 to 6, wherein said comonomers comprising (A), (B) and (C).

9. The copolymer of Claims 1 to 6, wherein (C) is at least one copolymeri¬ zable vinylic organosiloxane having the essential constituent units below:

M', P - chain -R'aSiO-_—a and

N', '^SiO^, 2 wherein P is a copolymerizable vinylic group, chain is a linkage of at least one chemical bond; all the molecules contain at least one M¹ group; the molar ratio of N¹ to M' is at least one; R¹ and R" are selected from a group consisting of H, substituted and non-substituted alkyl, alkenyl, cyclohexyl and phenyl; a is an integer of 0 to 2 inclusive and b is an integer of 0 to 3 inclusive and (D) is at least one copolymerizable fluorinated vinylic monomer having the general structure, PVG"-Y, wherein PVG" is a copolymerizable vinylic group selected from vinyl, methacryloxy,- methacrylamido and styrenyl and Y is a fluorinated group selected from a fluorinated alkyl, cyclohexyl and phenyl, substituted and non-substituted.

10. The copolymer of Claim 9, wherein the comonomer comprising (A), (B), (C) and (D).

11 . The copolymer of Claim 9 , wherei n the comonomers compri si ng (A) ,

( B) and (C ) .

12. The copolymer of Claim 9, wherein said chain is selected from 1 to 12 chemical bonds.

13. The copolymer of Claim 9, wherein C, the number of M¹group in each molecule is one and the molar ratio of N'to M' is at least one.

14. An artificial membrane for burn or wound dressing prepared from a copolymer of Claim 11.

15. An eye protective membrane for cornea injury, disease or drug release prepared from a copolymer of Claim 11.