Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F222/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical and containing at least one other carboxyl radical in the molecule; Salts, anhydrides, esters, amides, imides, or nitriles thereof
  • C08F222/10—Esters
  • C08F222/1006—Esters of polyhydric alcohols or polyhydric phenols
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F290/00—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
  • C08F290/02—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups on to polymers modified by introduction of unsaturated end groups
  • C08F290/06—Polymers provided for in subclass C08G
  • C08F290/062—Polyethers
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
  • G02B1/041—Lenses

Definitions

• the invention relates to UV-cured optical elements, a process for the manufacture of such optical elements, and the use of UV-curable compositions in the preparation of UV-cured optical elements.
• UV-curing ultraviolet light
• the properties of the resulting UV-cured lens do not differ from those of lenses prepared by thermal curing. Especially important are colour, homogeneity, impact strength (brittleness), and hardness.
• European patent application 0 441 383 discloses compositions comprising polybutylene glycol di(meth)acrylate having at least 5, but preferably more than 7 butylene glycol units (having at least 26 and at least 36 atoms in the main chain, respectively) and a monomethacrylate, e.g., benzyl methacrylate. These compositions may be used to obtain UV-cured lenses. However, a lens prepared from such a composition shows a hardness which is too low to be acceptable. EP-A-0 441 383 therefore discloses the use of a third component, e.g., a urethane- or epoxy poly(meth)acrylate which imparts hardness to the ophthalmic lens.
• a third component e.g., a urethane- or epoxy poly(meth)acrylate which imparts hardness to the ophthalmic lens.
• the present invention relates to a UV-cured optical element, substantially halogen free, comprising the reaction product of a composition comprising:
• Ri and R 2 are independently chosen from hydrogen or methyl groups
• R is a linear or branched C 2 -C 23 alkylene group optionally substituted with:
• R 3 is hydrogen or a methyl group
• R 4 , R 5 , R 6 , R 7 , and R 8 are independently selected from hydrogen, epoxy, cyano, amino, thiol, hydroxy, nitro, and amido groups, C r C 20 alkyl groups, C 2 -C 20 alkenyl groups, C 2 -C 20 alkynyl groups, C 3 -C 20 cycloalkyl groups, C 6 -C 20 aryi groups, C 7 -C 20 aralkyl groups, and C 7 - C 20 alkaryl groups, which groups may be linear or branched, may optionally contain one or more oxygen, nitrogen, sulphur, sulphoxy, sulphone, -O-CO, or -CO-O- atoms or groups, and may optionally be substituted with epoxy, cyano, amino, thiol, hydroxy, nitro, and amido groups; and
• the length of the polyalkylene glycol main chain may be defined by an average chain length. All polyalkylene glycol di(meth)acrylates present in the composition have to be taken into account to calculate the average chain length.
• the average chain length of the main chain -0-(R-0-) n - in a mixture of compounds is the sum of the multiplications of the mole fraction of a certain compound by the particular main chain length of that compound.
• the average chain length of PEG200DiMA is calculated as follows:
• the average chain length is again calculated by taking all polyalkylene glycol di(meth)acrylate compounds present into account.
• R group may, then, be selected independently from the other(s) from the definition provided above for R, e.g., as presented in the following structure:
• R is a C2 and/or C3 linear or branched alkylene group, i.e. 1 ,2- ethylene, 1 ,3-propylene, and/or 1 ,2-propylene group.
• R., and R 2 are methyl groups.
• n ranging from 1 to 20, more preferably from 1 to 15, most preferably 1 to 10.
• the average chain length is preferably 5 to 22 atoms, more preferably 5.5 to 19 atoms, and most preferably 6 to 16 atoms.
• R 4 , R 5 , R 6 , R 7 , and R 8 preferably are hydrogen atoms. More preferably, the compound of formula II is benzyl methacrylate.
• the comonomers may be acrylic, vinylic, allylic or mixtures thereof. Examples include methyl acrylate, methyl methacrylate, phenyl methacrylate, vinyl acetate, vinyl benzoate, ethoxylated Bisphenol A dimethacrylates, diallyl isophthalate, and diallyl phthalate.
• the composition comprises less than 5 wt% of a comonomer.
• the composition consists of 30-70 wt% of at least one polyalkylene glycol di(meth)acrylate of formula I and 70-30 wt% benzyl (meth)acrylate or a derivative thereof of formula II.
• compositions comprising 30-70 wt% of a polyalkylene glycol di(meth)acrylate, or a mixture of polyalkylene glycol di(meth)acrylates, with an average chain length from 5 to 22 atoms, and 70-30 wt% of benzylmethacrylate.
• composition of the present invention is preferably applied in an ophthalmic lens.
• Japanese patent application 59 136310 discloses liquid compositions comprising benzyl methacrylate and polyethylene glycol dimethacrylate for optical elements. However, the compositions are stated to be cured thermally using a peroxide. Moreover, the compositions also comprise 40-
• the present invention relates to a substantially halogen free lens, i.e., less than 10 wt% of halogen-containing compounds, preferably less than 5 wt%, while most preferably the composition does not contain any halogen-containing compounds.
• GB-2176794-A discloses a copolymer characterised by, inter alia, a high refractive index which is suitable for processing into optical lenses.
• a monomer mixture comprising at least a) a (meth)acrylate which optionally is chlorinated or brominated, b) a di(meth)acrylate which optionally is chlorinated or brominated, and c) a third monomer which typically is chlorinated or brominated and gives the desired high refractive index, is polymerized.
• a benzylmethacrylate is included in the mixture, a brominated monomer is also used.
• the mixtures are polymerized by means of an organic peroxide using heat. The use of brominated and/or chlorinated monomers in UV-cured compositions, as argued above, is unacceptable. There is no suggestion in GB-2176794-A that lenses according to the invention can be made.
• Japanese patent application 61 1141716 discloses optical elements prepared from 10-80 wt% methyl methacrylate, 20-80 wt% of a monomethacrylic ester, and 0.3-10 wt% of a crosslinking monomer, e.g., n-
• C 4 - 12 alkylene glycol di(meth)acrylate At least 90 wt% of such a composition consists of monofunctional, relatively small monomers.
• the composition may also contain one or more conventional additives to act as release agents, dyes, pigments, ultraviolet light absorbers, etc., each preferably in quantities not higher than 1 wt%.
• compositions according to the present invention are UV-curable.
• the compositions When, after addition of a photo initiator, the compositions are poured into glass moulds and irradiated, they result in hard and homogeneous castings that are not yellowed and are not brittle.
• the hardness of the lens is usually expressed as Barcol hardness.
• the lenses Preferably have a Barcol hardness greater than 15. More preferably, the Barcol hardness is greater than 25, while a Barcol hardness greater than 30 is most preferred.
• the UV-polymerisation process is initiated by photoinitiators in a conventional way.
• the cast composition comprising 0.001 to 1 wt% of photoinitator is subjected at least once to UV-light to polymerise the composition.
• the time necessary to complete polymerisation ranges from 20 seconds to 5 hours. It may include one or more dark time periods, in which the sample is taken out of the UV-irradiated area, in order to prevent the cast composition temperature from getting too high.
• photoinitiators are methylphenyl glyoxylate, n-butylbenzoin ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-benzoylcyclohexan-1-ol, benzophenone, 2,4,6-trimethylbenzoyldiphenyl phosphine oxide, and mixtures thereof.
• the lens can be subjected to further physical or chemical treatment such as surface polishing, antistatic treatment, hard coating, non-reflective coating, dyeing or photochromic treatment as needed in order to prevent reflection, improve abrasion resistance, improve chemical resistance, impart hardness, impart anti-mist properties or impart fashionability.
• further physical or chemical treatment such as surface polishing, antistatic treatment, hard coating, non-reflective coating, dyeing or photochromic treatment as needed in order to prevent reflection, improve abrasion resistance, improve chemical resistance, impart hardness, impart anti-mist properties or impart fashionability.
• EGDiMA ethylene glycol dimethacrylate
• TEGDiMA triethylene glycol dimethacrylate
• TTEGDiMA tetraethylene glycol dimethacrylate
• PEG200D ⁇ MA polyethylene glycol dimethacrylate in which the average molecular weight of the polyethylene backbone equals 200
• PEG400DiMA polyethylene glycol dimethacrylate in which the average molecular weight of the polyethylene backbone equals 400.
• chain length average chain length of the main chain in number of atoms
• Examples 1-8 The procedure of Examples 1-8 was repeated. However, in comparative Examples A and B use was made of EGDiMA, and in comparative Examples C, D, and E PEG400DiMA was employed. The results are given in Table 3. As can be seen from the results in Table 3, the lenses made from the compositions of Comparative Examples A-B were far too hard and brittle (and therefore cracked) to be employable. On the other hand, the compositions of Comparative Examples C-E resulted in lenses which were soft and flexible, due to the fact that the average chain length is too long.

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• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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• 1997
  • 1997-10-14 EP EP97913162A patent/EP0938689A1/de not_active Withdrawn
  • 1997-10-14 JP JP52099498A patent/JP2001503797A/ja active Pending
  • 1997-10-14 WO PCT/EP1997/005763 patent/WO1998020373A1/en not_active Application Discontinuation

Non-Patent Citations (1)

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