Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
  • C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
  • C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
  • C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D213/62—Oxygen or sulfur atoms
  • C07D213/63—One oxygen atom
  • C07D213/64—One oxygen atom attached in position 2 or 6
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
  • C07C45/45—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by condensation
  • C07C45/455—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by condensation with carboxylic acids or their derivatives
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C69/00—Esters of carboxylic acids; Esters of carbonic or haloformic acids
  • C07C69/62—Halogen-containing esters
  • C07C69/65—Halogen-containing esters of unsaturated acids
  • C07C69/653—Acrylic acid esters; Methacrylic acid esters; Haloacrylic acid esters; Halomethacrylic acid esters
• • 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
  • C08F20/00—Homopolymers and 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
  • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
  • C08F20/10—Esters
  • C08F20/22—Esters containing halogen
• • 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
  • C08F20/00—Homopolymers and 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
  • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
  • C08F20/10—Esters
  • C08F20/34—Esters containing nitrogen, e.g. N,N-dimethylaminoethyl (meth)acrylate
• • 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
  • C08F20/00—Homopolymers and 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
  • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
  • C08F20/10—Esters
  • C08F20/38—Esters containing sulfur

Definitions

• This invention relates to acrylates in which a large percentage of hydrogen atoms have been replaced by halogens and to polymers that include mer units derived from such halogenated acrylates.
• Optically transparent polymers especially those used for telecommunication applications, must have low absorptive loss in the infrared wavelengths, typically 1260-1360 nm and 1480-1580 nm. However, because these wavelengths are close to overtones of carbon-hydrogen bond vibration frequencies, minimization of the number of carbon-hydrogen bonds is desirable. While some organic compounds with few C-H bonds are known, additional considerations of optical transparency, ease of polymerization, refractive index, chemical and mechanical stability, and the need to compete on a cost basis with glass prevent many such compounds from widespread use in polymeric optical devices.
• U.S. Patent Nos. 3,668,233, 3,981,928, and 4,010,212 describe acrylic acid esters (i.e., acrylates), prepared from esterification of acrylic acid with perfluoro- tertiary alkyl alcohols such as perfluoro-t-butyl alcohol, that can be used as inert heat exchange fluids and as homopolymeric water- and/or oil-repellent surface coatings.
• acrylic acid esters i.e., acrylates
• perfluoro- tertiary alkyl alcohols such as perfluoro-t-butyl alcohol
• European Patent Application No. 282,019 describes highly fluorinated, transparent acrylates specifically tailored for optical articles. These materials are prepared from cyclic or bicyclic alcohols containing few or no carbon-hydrogen bonds.
• U.S. Patent Nos. 3,520,863 and 3,723,507 describe a number of perfluorocycloalkyl acrylates and polymers thereof. Use of tertiary alcohols is not reported, and optical properties of the polymers are not discussed.
• U.S. Patent No. 5,045,397 describes the preparation and use of certain adhesives to be used in optical systems. A polymeric adhesive of a specified refractive index is prepared by copolymerization of specified monomers of known refractive indices. While some lightly fluorinated monomers are described, highly fluorinated monomers are not disclosed.
• U.S. Patent No. 5,223,593 describes acrylate monomers and their (co)polymers designed to have low C-H bond density relative to poly(methylmethacrylate) so as to reduce vibrational band intensities in plastic optical fiber cores. Absorbance at 600-1200 nm was reduced, but absorbance at higher frequencies is not reported.
• the described acrylates were prepared from highly fluorinated primary alcohols.
• U.S. Patent No. 5,093,888 describes a polymeric optical device (specifically, an injection-molded Y-shaped splitter waveguide) that uses an amorphous polymeric adhesive that includes 2,2,2-trifluoroethyl methacrylate having a refractive index of 1.418 to hold optical fibers in a polytetrafluoro- ethylene spacer containing a fluorinated polyetheretherketone core.
• U.S. Patent No. 5,311,604 describes a method of manufacturing a polymeric optical interconnect.
• Useful polymers are said to be those transparent to the wavelength of light to be utilized.
• Listed examples include poly(methylmethacrylate) ("PMMA”), polycarbonates, polyurethanes, polystyrenes, and polyolefins.
• PMMA poly(methylmethacrylate)
• polycarbonates polyurethanes
• polystyrenes polystyrenes
• polyolefins polyolefins.
• a "copolymer of deuterated PMMA-d8 (sic) and tetrafluoropropyl methacrylate” is used to adhere optical fibers to a molded PMMA device.
• U.S. Patent No. 5,343,544 describes a polymeric optical interconnect.
• the device includes polymeric substrate and covering members that can be fabricated from, for example, a combination of fluorinated and non- fluorinated photopolymerizable (meth)acrylate and di(meth)acrylate monomers. The same combination of monomers is said to be useful for sealing optical fibers in the device.
• Substitution of fluorines for hydrogen atoms in the polymer is said to be capable of reducing the refractive index of the polymer and to reduce losses in near infrared wavelengths, but no example of a haloacrylate-only system and no indication of the degree to which loss or refractive index can be controlled are given.
• Copolymerization of two or more monomers is said to be able to provide a copolymer having a tailored refractive index.
• Fiber optic branching components include parameters for optical loss (i.e., loss that is in excess over that which is inherent in the device), useable wavelength ranges, resistance to performance variability caused by temperature and humidity, optical cross talk, water immersion, flammability, etc. All such parameters can depend, at least in part, on the materials used to make the device.
• materials must have very low absorptive losses in the wavelength regions of 1260 to 1360 nm (nominally 1310 nm) and from 1480 to 1580 nm (nominally 1550 nm), over which ranges low losses must be maintained under extreme temperature and humidity conditions.
• the inherent loss is calculated to be 3.01 decibels (dB), where a decibel is defined as -10 log(I /I.) in which I is the intensity of the output and I. is the intensity of the input.
• Maximum allowable excess loss in a 1 x 2 splitter is quantified as, e.g., no more than 0.25 dB per fiber plus no more than 0.5 dB per waveguide junction connecting an input fiber to an output fiber.
• Presently available materials other than glass have not proven to be able to meet all, or even most, of these rigid requirements.
• the present invention provides halogenated acrylates having the general formula
• M is H, CH 3 , F, Cl, Br, I, or CF 3 ; preferably M is H, F, or Cl; most preferably M is H because of availability, reactivity, and thermal stability; A is oxygen or sulfur; and
• Z can be a group having a maximum of 150 carbon atoms and can be
• each R independently is F, Cl, or Br
• R is any group from (a)(i), (a)(ii), (a)(iii), (a)(iv), and (a)(v),
• n is a whole number in the range of 0
• each R independently can be (a) a perfluorinated, perchlorinated, or per(chlorofluoro)
• R is any group from (a)(i), (a)(ii), (a)(iii),
• E can be R r 5
• R , R " , R . and Q are defined as above; or (4) -CR f (E) 2 , wherein each E independently is as defined above, and R is as defined above.
• the present invention provides a polymer that includes at least one mer unit derived from the above-described haloacrylates as well as optical devices and optical materials made from such a polymer.
• this invention provides di- and tri-functional acrylates as crosslinking agents with low hydrogen content, usually no more than the required three H atoms around each acrylate group.
• this invention provides ether-containing perhalo-, preferably perfluoro- and perchlorofluoro ketones as intermediates to low H- content acrylates.
• Preferred compounds include 1 ,2-dichloroperfluoroethyl ether and 1,1,2-trichloroperfluoroethyl ether derivatives which can be prepared by the direct fluorination of a 1,1-dichloroethyl ether and 1,1,1-trichloroethyl ether, respectively.
• this invention provides 1,2- dichloroperfluoro/per(chlorofluoro) ethers useful in the synthesis of the above acrylates and also useful as precursors to perfluorovinyl ether monomers optionally substituted by functional groups.
• Preferred perfluorinated ketones have the structure R 5 f OCF 2 COCF 3 , R 5 f OCF 2 COCF 2 Cl, and R 5 f OCF 2 COCF 2 OR 5 r . wherein R is a linear perfluoroalkyl or perfluorooxyalkyl group having from two to twenty carbon atoms.
• group or “compound” or “monomer” or “polymer” or “mer unit” means a chemical species that allows for substitution by conventional substituents that do not interfere with the desired product such as, for example, linear or branched alkyl or haloalkyl groups;
• optical coupler or "interconnect” means a device that joins one or more input optical fibers to one or more output optical fibers and includes devices such as splitters and combiners;
• acrylate includes corresponding “methacrylate” and other 2- substituted acrylates throughout this application.
• the halogenated acrylates of the present invention have relatively few C-H bonds, usually no more than three (i.e., those around the acrylate unsaturation) or no more than five (around methacrylate unsaturation).
• This dearth of hydrogens means that these compounds have very little absorption in the infrared wavelengths of interest, i.e., 1260-1360 nm and 1480-1580 nm. Because these materials can be used in optical applications, particularly devices that guide light such as waveguides and optical interconnects, minimizing loss of signal due to absorption by the material of which the device is made is very important and desirable.
• the acrylates of the present invention are highly halogenated, they are relatively easy to polymerize, are optically clear, have low optical loss, are liquids or solids with relatively low melting points or dissolve sufficiently in lower-melting comonomers, provide amorphous polymers with good thermal stability and high molecular weights, and provide polymers (typically copolymers) having indices of refraction that effectively match those of glass optical fibers. These characteristics make them excellent candidates for use as materials in polymeric optical devices, especially waveguides and optical couplers.
• optical devices made from glass are manufactured in one-at-a-time, handwork operations that are very labor intensive and prone to low productivity.
• Polymers of the invention can be processed automatically by known polymer processing methods into optical devices that are physically robust and are substantially identical, leading to significant improvements in product reliability and economics.
• Polymeric optical devices of the present invention can be mass produced and can be handled under severe field conditions without undue damage and/or loss of properties.
• FIG. 1 is a comparison of absorption vs. wavelength plots of a polymer derived from one embodiment of the halogenated acrylates of the present invention with two comparative halogenated polyacrylates.
• Halogenated acrylates of the present invention are useful for various optical applications. They display several highly desirable characteristics including ease of polymerization, optical clarity, favorable melting points, and polymers therefrom exhibit very little absorption in critical infrared regions (i.e., 1260-1360 nm and 1480-1580 nm), thus minimizing optical loss due to absorption.
• critical infrared regions i.e., 1260-1360 nm and 1480-1580 nm
• the resulting polyacrylate is amorphous, has good thermal stability, has relatively high molecular weight, and can have an index of refraction that effectively matches that of a glass optical fiber.
• halogenated acrylates of the invention can be copolymerized to prepare copolymers having specifically desired physical properties, such as refractive index (n ), glass transition temperature (Tg), optical absorption, etc.
• refractive index (n ) refractive index
• Tg glass transition temperature
• optical absorption etc.
• Halogenated acrylates of the present invention have the general formula
• acrylates are a broad class of polymerizable materials, the chemistry of which is well defined.
• M typically is H, other substituents such as CH , F, Cl, Br, I, or
• CF can be used in place of hydrogen.
• any such substitution should be done while keeping in mind the desired performance characteristic(s) of the material (e.g., polymer index of refraction, ease of polymerization, liquidity at the temperature(s) of use, very little absorption in the critical infrared regions, monomer availability, and cost, etc.).
• Many acrylates meet several of the aforementioned criteria regarding acceptable materials. For example, acrylates have relatively low melting points and can be polymerized to amorphous polymers with high molecular weights. However, heretofore available acrylates have not been able to meet those criteria relating to optical performance. Specifically, such acrylates have had unacceptably high absorption in the aforementioned infrared wavelength regions. In contrast, halogenated acrylates of the present invention have acceptably low absorption in these wavelength regions.
• A can be either oxygen or sulfur.
• acrylate normally would include only those compounds where A is oxygen, for present purposes, the term includes those compounds where A is sulfur.
• the Z moiety in the above formula serves at least two important functions.
• the index of refraction of the polymerized halogenated acrylate helps in tailoring the index of refraction of the polymerized halogenated acrylate. Because the index of refraction of optical fiber cores and cladding layers generally fall in the range of 1.44 to 1.46, this is a desirable index of refraction range for optical materials of the invention.
• homopolymers prepared from the halogenated acrylates of the present invention have an index of refraction of between about 1.36 and about 1.56.
• acrylate monomers can be mixed to provide copolymers having an index of refraction in the desired range. Since the index of refraction of most glass used in optical fiber cores is approximately 1.457, a preferred index of refraction of a copolymer of the invention can be approximately 1.450.
• the index of refraction of a core desirably is slightly higher than the clad, and the core index of refraction desirably matches the index of refraction of an optical fiber core, which fiber is connected to the device.
• the index of refraction of the clad in a device can be slightly less than that of the core (the difference preferably is about 0.007).
• the bulk of the Z moiety assists in keeping low the weight percentage of hydrogen in the halogenated acrylates of the present invention.
• keeping the weight percentage of hydrogen in the compound as low as possible is desirable.
• a haloacrylate of the invention wherein A is O and M is H desirably has a molar volume of at least 150 mL/mole, more preferably at least 200 mL/mole, and even more preferably at least 250 mL/mole.
• the corresponding halomethacrylates wherein A is O and M is CH require higher molar volumes to meet the 0.1 dB/cm (at 1480 nm) absorption loss criterion.
• Z serves the important function of increasing the molecular volume without adding hydrogen atoms to the halogenated acrylate of the present invention so that the effect of the hydrogen atoms surrounding the double bond is minimized.
• Copolymers of halogenated acrylates where one or more of the monomers includes a relatively small Z group and one or more monomers includes a relatively large Z group, such that the overall molar volume of the copolymer is at least 150 mL/mole, also are within the scope of the present invention.
• Z group influences the chemical stability and melting point of the monomer and resulting (co)polymer(s).
• any one of three types of substituents on the ester portion of the acrylate are preferred: inclusion of an ether oxygen in an aliphatic or aromatic group; mixtures of positional isomers of aromatic substituents; and branched aliphatic moieties; as well as combinations thereof.
• Z can be one of four types of groups.
• Z can have the general formula — C(RJ E, wherein each R group and E are as defined above.
• each R examples of potentially useful C -C acyclic aliphatic groups include methyl, methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, methoxyethoxymethyl (i.e., CF OCF CF OCF ), methoxypropoxymethyl, methoxyethoxyethoxymethyl, ethoxyethoxymethyl, ethoxyethyl, and methoxyethyl groups.
• alkyl group having more than two carbon atoms, isomers thereof, particularly branched isomers, are included in this definition.
• all alkyl groups are fluoroalkyl, chloroalkyl, or fluorochloroalkyl groups; that is, all hydrogen atoms have been replaced by fluorine atoms, chlorine atoms, or combinations thereof.
• Any of the cycloaliphatic groups can include C -C straight- chain or branched aliphatic carbon substituents, as well as above-named acylic aliphatic groups, at any position thereof, consistent with steric bulk considerations.
• all hydrogen atoms of the cycloaliphatic groups are to be replaced by fluorine atoms, chlorine atoms, or combinations thereof.
• R f groups as potentially useful C 6 -C 20 aryl groups include phenyl, naphthyl, indenyl, biphenyl, anthracyl, phenanthryl, and fluorenyl groups, wherein all hydrogen atoms have been replaced by fluorine atoms, chlorine atoms, bromine atoms, or combinations thereof.
• R groups as potentially useful C -C alkaryl groups include methylphenyl, ethylphenyl, methylnaphthyl, dimethylphenyl, indanyl, and butylphenyl groups, wherein all hydrogen atoms have been replaced by fluorine atoms, chlorine atoms, bromine atoms, or combinations thereof.
• R groups as potentially useful C -C aralkyl groups include phenethyl and benzyl groups, wherein all hydrogen atoms have been replaced by fluorine atoms, chlorine atoms, bromine atoms, or combinations thereof.
• R groups comprising C -C heteroaryl, heteroaralkyl and heteroalkaryl groups include any cyclic aromatics comprising at least one oxygen, nitrogen or sulfur atom in the ring, including those having C -C straight-chain or branched aliphatic carbon substituents, as well as above-named acylic aliphatic groups, at any position thereof, consistent with steric bulk considerations.
• Useful heteroaromatics include furan, thiophene, pyrrole, 1,2- and
• R groups can comprise analogous fused-ring heteroaromatic compounds including benzofuran, thionaphthene, indole, isothionaphthene, isobenzofuran, isoindole, 1,2- and 1 ,4-benzopyran, 1,2- and 1,4-benzothiopyran, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, phthalazine, benzoxazole, benzothiazole, benzimidazole, benzpyrazole, benzotriazole, and numerous fused ring groups comprising three or more rings comprising at least one N-, O-, or S- atom, including any of these having C -C straight-chain or branched aliphatic carbon substituents, as well as above-named acylic aliphatic groups, at any position thereof, consistent with steric bulk
• R groups that can be particularly useful for certain applications include methyl, chloromethyl, ethoxymethyl, (2-chloroethoxy)methyl, trichloroethoxymethyl, hexyl, cyclohexyl, and butoxymethyl.
• R groups including branched aliphatic or alkyl groups may be preferred when mixtures of branched isomers or stereoisomers can be obtained that result in lowering of the haloacrylate melting point to provide ease of handling of the monomers.
• E represents one of four substituents. Specifically, E can be R .
• each R 1 or R 2 is F.
• At least one R is F, OC F , SC F CF , OC(O) 'C 6 F 5 , or OSO 2 C 4 F 9.
• Z can have the formula CR (E) wherein each E and R are as previously defined.
• Some preferred halogenated acrylates of the present invention having homopolymers with refractive indices greater than or equal to 1.457 are represented by the following formulae:
• halogenated acrylates of the present invention having homopolymers with refractive indices less than 1.457 (i.e., "low index materials") are represented by the following formulae:
• halogenated acrylate monomers of the invention include at least one perfluoroether moiety.
• An ether linkage allows ready variation of the structure of a starting material to be fluorinated and of the fluorinated product. It has been found that the perfluoroether group provides favorable physical properties, such as low melting point or liquidity at 23° C, while allowing control of the refractive index of the corresponding homopolymer and related copolymers by control of structure and substituents. Homopolymers prepared from these acrylates have characteristic indices of refraction.
• one or more of these compounds can choose as halogenated acrylate the homopolymer of which has an index of refraction that matches that which is desired or can choose two or more of these acrylate monomers and copolymerize them so as to provide a polymer that has the desired index of refraction.
• FIG. 1 shows absorption versus wavelength plots for three halogenated polyacrylates: poly(perfluorophenylacrylate) (PFPA) (comparative tracing C), poly(perfluorophenylthioacrylate) (PFPTA)(comparative tracing B), and compound Vm of the present invention (tracing A), above.
• PFPA poly(perfluorophenylacrylate)
• PFPTA poly(perfluorophenylthioacrylate)
• compound Vm of the present invention tracing A
• Halogenated acrylates of the present invention can be prepared by reacting an acrylic acid derivative such as acryloyl chloride or acrylic anhydride with a perhalogenated alcohol, alkoxide, or alkoxy-substituted alcohol in the presence of an organic base (e.g., a tertiary amine).
• an organic base e.g., a tertiary amine.
• 2- acryloyloxyheptafluoronaphthalene (compound V) as an example, one can react heptafiuoro-2-naphthol with acryloyl chloride and triethylamine in an appropriate solvent such as acetonitrile.
• Perhalogenated alkoxides may be prepared from the corresponding perhalogenated alcohols by treatment with base, or by treatment of a perhalogenated carbonyl compound with an alkali metal fluoride (e.g. KF) or perhalogenated carbanion sources such as organometallic reagents (e.g., organo lithiums or Grignard reagents).
• Perhalogenated alcohols or carbonyl compounds may be prepared by the following methods:
• the perhalogenated ketone may be prepared by similar addition of a perhalogenated organometallic compound to a perhalogenated acid fluoride, or may be prepared by direct fluorination of an ester of a secondary alcohol followed by cleavage of the resulting perhalogenated secondary ester.
• a preferred class of perhalogenated alcohols or ketones is ether-containing perhalogenated alcohols or ketones. These may be prepared by direct fluorination of an ether-containing precursor ester of a primary or secondary alcohol. For example, they may be prepared by reaction of an alcohol and either propylene glycol (Scheme 1) or epichlorohydrin (Scheme 2) to produce a secondary alcohol, which may then be acylated, fluorinated by direct fluorination, and the resulting perhalogenated ester cleaved by any of the methods described in U.S. Pat. No.
• R is a linear perfluoroalkyl or perfluorooxyalkyl group having from two to twenty carbon atoms.
• R is a linear alkyl or oxyalkyl group which can be terminated by any of -CH , -CH(CH ) 2 , -C(CH ) 3 , -OCH -OCH(CH , or -OC(CH ) 3 , wherein
• each R is the perhalogenated analog of R , R and R groups having from 1 to 20 carbon atoms, ' and Y can be Cl, ' OR and Y f can be Cl or OR f .
• Preferred classes of the perfluorinated ether ketone intermediates are those mono- and diethers in which
• R is a perfluoro or per(chlorofluoro)alkyl group of 2-12 carbons and containing up to 5 ether oxygens. Similarly, direct fluorination of the di- or tri-esters can lead to di- or tri-ketones.
• Halogenated acrylates containing bromine or chlorine in addition to fluorine are useful in increasing the refractive index of the corresponding homo- and co-polymers.
• Chlorofluoroalkyl acrylates may be prepared by the previously described methods from either chlorofiuoroketones or chlorofluoroacyl halides. See Example 24. Higher amounts of chlorine in the acrylate are especially useful in raising the refractive index.
• 1,1- dichloroethoxy ethers and 1,1,1-trichloroethoxy ethers when subjected to direct fluorination, undergo a rearrangement to produce 1,2-dichloro-perfluoroethoxy ethers and 1,1,2-trichloro-perfluoroethoxy ethers respectively. See Examples 11 and 21, and Table 4, compounds 4-2, 4-3, and 4-22. This rearrangement is illustrated in one embodiment, as follows:
• R is a C - C alkyl- or acyl-containing group optionally g containing up to 5 ether oxygen atoms and R is the corresponding perhaloalkyl or perhaloacyl-containing group, optionally containing up to 5 ether oxygen atoms.
• Perhaloalkyl or perhaloacyl-containing esters can be cleaved to produce perhaloketones and perhaloacid fluorides as previously described.
• Preferred compounds have the formulae C1CF CFC1OR and g
• Cl CFCFCIOR and are made by direct fluorination of compounds of the formulae Cl 2 CHCH 2 OR 8 and Cl 3 CCH 2 OR 8 , resp r ectively ⁇ , wherein R 8 can be a C 1 -C 20 alky " ⁇ l-or acyl-group optionally containing up to 5 ether oxygen atoms and R can be the corresponding perfluoroalkyl or perfluoroacyl-containing group, optionally containing up to 5 ether oxygen atoms.
• 1,2-dichloroperfluoroethyl ethers and 1,1,2-trichloroperfluoroethyl ethers are useful as solvents and in the preparation of perfluoro- and chloroperfluorovinyl ethers (see U.S. Pat. No. 5,350,497).
• a preferred subset of these 1,2-dichloro g perfluoro/per(chlorofluoro) ethers is that in which the R group contains 1 to 12 carbon atoms and up to 5 ether oxygen atoms.
• Another preferred subset is that in g which the preferred R group also contains a COF or SO .
• F group Refractive index and optical absorbance data for several of the compounds whose structures are shown above are given in Table 1, below.
• Table 1 show that a number of candidate haloacrylates have acceptably low absorbances in the target wavelength regions.
• these data show that homopolymer refractive index calculations (W. Groh and A. Zimmermann, Macromolecules, 24, (December, 1991), p. 6660) cannot predict the observed refractive index, particularly in light of a need to predict refractive index with accuracy in the third decimal point.
• the halogenated acrylates of the present invention are relatively easy to polymerize. Like most acrylates, they are free radically polymerizable, often in less-than-rigorous conditions. In other words, although oxygen normally must be excluded from the area where an acrylate polymerization is performed, other materials (e.g., water) need not be so excluded.
• the free radical polymerization of the halogenated acrylates of the present invention can be initiated by heat or by light, optionally but preferably in the presence of a thermal or photo initiator, respectively.
• a thermal or photo initiator for example, photoinitiation, particularly UV-type photoinitiation, is preferred.
• photoinitiation particularly UV-type photoinitiation, is preferred.
• an initiator consideration of the aforementioned optical loss goals should be considered. For instance, certain UV initiators are highly
• UV initiator that has not proven to be especially absorptive in the wavelengths of interest is 2,2-diethoxyacetophene, Ph- C(O)CH(OCH 2 CH 3 ) 2 , wherein Ph is phenyl, hereinafter referred to as DEAP.
• halogenated acrylate polymers of the invention may be crosslinked. Physical property changes achieved by crosslinking acrylate polymers include elevated Tg, increased strength, reduced swelling when exposed to solvent or other small molecules, and reduced flexibility.
• Typical acrylate crosslinkers have C-H bonds in addition to those in the acrylate functionality and may detrimentally affect optical absorbances in the important 1260 to 1360 nm and 1480 to 1580 nm wavelength regions (supra).
• polyfunctional acrylate crosslinkers with fewer C-H bonds in the molecule, preferably with CH only in the acryloyl group and on the ⁇ -carbon atoms of the polyol moiety, more preferably limiting the C-H bonds to only those of the acrylate groups (i.e., no other C-H bonds in the molecule).
• the crosslinker may be present at a relatively minor component and, as such, a higher hydrogen content can be tolerated.
• Acrylates prepared from perhalogenated aromatic polyols fit this criterion. Illustrative examples of these polyfunctional acrylates include tetrafluorohydroquinone diacrylate (XX), tetrafluororesorcinol diacrylate (XXI), and octafluoro-4,4'-biphenol diacrylate (XXII).
• Acrylates of other halogenated (chlorinated or brominated) aromatic polyols may also be useful as crosslinkers of this invention.
• the corresponding polyfunctional homologous methacrylate crosslinkers may be substituted for any of the acrylate crosslinkers noted herein.
• brominated aromatic polyols may be readily purchased or can be synthesized, e.g., by the reaction of bromine with an aromatic polyol as is known in the art. Reaction of the brominated aromatic polyol with, for example, acryloyl chloride in the presence of a base such as triethylamine provides the desired acrylates of the brominated aromatic polyols.
• acrylated perhalogenated aromatic polyols include tetrachlorohydroquinone diacrylate, tetrabromocatechol diacrylate (XXIII), tetrachlorocatechol diacrylate, tetrabromoresorcinol diacrylate, tetrachlororesorcinol diacrylate, tribromophloroglucinol triacrylate (XXIV), tribromopyrrogallol triacrylate (XXV), and tribromo-l,2,4-benzenetriol triacrylate (XXVI).
• Tribromoresorcinol diacrylate and trichlororesorcinol diacrylate can also be useful as crosslinkers. They may be useful in optical devices where the number of hydrogen atoms is less important.
• Non-aromatic acyclic aliphatic halogenated polyol polyacrylates may also be useful as crosslinking agents in the invention.
• Polyacrylates can be prepared by, e.g., the reaction of a perhalogenated polyol with an acryloyl halide, preferably acryloyl chloride.
• Perhalogenated polyols can be prepared by the perfluorination of an aliphatic hydrocarbon-polyols or a halogenated, preferably chlorinated, aliphatic polyol by known fluorination methods, such as direct fluorination.
• R preferably is an acyclic aliphatic halogenated group, free of ethylenic or other carbon-carbon unsaturation, having at least 1 carbon atom and optionally can comprise up to 50, preferably up to 10, non-carbon atoms such
• R can comprise an oligomeric polyether, oligomeric polyamine, oligomeric polythiol or .9 polyetheramine, such that the total number of atoms in the R chain (i.e., the combination of carbon atoms and linking oxygen, nitrogen or sulfur atoms) can be up to 150, preferably up to 50, more preferably up to 25, and most preferably no
• Halogen atoms comprising the R group can be fluorine, chlorine or bromine, preferably fluorine or chlorine, more preferably a combination of fluorine and chlorine, and most preferably exclusively fluorine.
• Representative acyclic aliphatic halogenated polyol polyacrylates are represented by the following formulae of fluorinated acrylates:
• Halogenated acrylates of the present invention are useful in the preparation of polymers wherein the refractive index and the optical loss of the polymer must be carefully controlled.
• Polymers and copolymers prepared from the monomers find use in the manufacture of optical devices such as splitters, couplers, light guides, and waveguides.
• (co)polymers of the present invention find use as adhesives and index matching compounds for joining optical elements such as lenses, mirrors, optical fibers, light guides, and waveguides.
• (Co)polymers of the invention find further use as cladding and/or protective materials for optical devices such as those named above as well as optical fibers.
• inventive monomers and polymers are useful in a variety of applications such as flame retardants, protective coatings, and adhesives.
• Acrylates from brominated aromatic polyols can have utility in raising the refractive index of any acrylate system requiring crosslinking and/or flame resistance.
• Polymer films were prepared from liquified monomers (or monomer mixtures) that were doped with 0.2 - 0.5% by weight, based upon the total weight of polymerizable monomer(s), of a photoinitiator, preferably PhC(O)CH(OCH CH ) (DEAP), syringe-filtered, deoxygenated, placed between two silicon-treated polyethylene terephthalate (PET) release liners and exposed to ultra-violet radiation from an Oriel 50 watt mercury arc lamp (Oriel Corp., Stratford, CT) or a Sylvania Blacklight fluorescent bulb (Sylvania 350 BL bulb,
• a photoinitiator preferably PhC(O)CH(OCH CH ) (DEAP)
• PET polyethylene terephthalate
• Oriel 50 watt mercury arc lamp Oriel Corp., Stratford, CT
• Sylvania Blacklight fluorescent bulb Sylvania 350 BL bulb
• Tg glass transition temperature
• the temperature range was expanded as needed. Measurements were made after two heat and cool cycles. The Tg was recorded as a midpoint determination of the point at which the derivative of the interpolated slope of the transition equaled zero.
• the index of refraction was determined by inserting an optical fiber capable of carrying light at the required wavelength n (typically, an 8mW continuous wave laser diode at 1300 nm) into a liquid monomer or mixture of monomers, polymerizing the monomer(s) as described above to obtain a polymer, and measuring the intensity of the back reflection from the interface of the fiber and the sample. This was compared to the intensity of back-reflection when the same fiber was immersed in a material of known index (water) at the probing wavelength. Using the value of the refractive index of the fiber itself, the index of the probed material was calculated. Solid materials were first melted and the fiber inserted.
• n typically, an 8mW continuous wave laser diode at 1300 nm
• the intensity of the incident light was modulated with a square-wave generator from a function generator (HP 8013 A Pulse Generator, Hewlett Packard Instruments, Palo Alto, CA) and the detected signal analyzed using a lock-in detector (Stanford Research Systems Model SR510 Lock-In Amplifier, Stanford Research Systems Inc., Sunnyvale, CA) which was given the same square- wave reference signal.
• the refractive index measurements were reproducible to ⁇ 0.0015.
• Liquefied monomer was doped with 0.2% by weight DEAP, filtered, deoxygenated, and placed in a plastic mold prior to polymerization.
• Polymerization was effected by exposure to a UV lamp, typically Oriel Model 6281, for 30 minutes followed by heat annealing at 60-80° C under UV light for an additional time of from 30 minutes to several hours in order to complete the polymerization reaction.
• Absorbance of the plugs was measured using a UV spectrometer (Model UV-3101PC, Shimadzu Scientific Instruments, Inc., Columbia, MD) equipped with an integrating sphere.
• Example 1 of U.S. Patent No. 5,326,919, incorporated herein by reference was added to the -40°C reaction mixture which was then allowed to warm slowly to room temperature.
• the reaction mixture was quenched with 200 mL of cold 5% aqueous HCl.
• the aqueous mixture was extracted with ethyl ether and the extracts were dried over MgSO and rotary evaporated to give pentachlorophenyl perfluoroethoxymethyl ketone (49% crude yield).
• Vacuum distillation 105-
• the isomeric mixture (47.8 g) was mixed with 12.5 mL acryloyl chloride in 200 mL cold methylene chloride and treated with 20 mL triethylamine dropwise.
• reaction was sti ⁇ ed for an hour at 0°C followed by two hours at room temperature. The reaction was then quenched with ice water, acidified with dilute
• the chlorononafluorodiphenyl ethers (23.4g) were mixed with 8.4 g of 85% KOH in 150 mL t-butanol and the mixture was refluxed for 17 hours.
• the reaction mixture was quenched with dilute HCl, extracted with CH Cl , dried over MgSO , and concentrated on a rotary evaporator.
• the product was vacuum distilled (35°C, 66 Pa) to give 19.6 g (84%) of a mixture of seven chlorohydroxyoctafluorodiphenyl ether isomers which were confirmed by spectroscopic analysis.
• the isomeric chlorohydroxyoctafluorodiphenyl ether mixture was mixed with 6.0 mL acryloyl chloride in 250 mL cold methylene chloride and 10 mL triethylamine was added dropwise. The mixture was sti ⁇ ed for 17 hours, filtered, and the filtrate was rotary evaporated. The residue (27. lg) was extracted with ethyl ether and the extracts were filtered and concentrated on a rotary evaporator. 9
• Tetrabromocatechol (25 g) was dissolved in 250 mL acetonitrile and the solution was cooled to 0°C in an ice bath. Triethylamine (17 mL) was added and the mixture was sti ⁇ ed at 0°C for two hours. Acryloyl chloride (10 mL) was added dropwise by syringe, the ice bath was removed, and the reaction was sti ⁇ ed for 16 hours. The reaction was quenched with ice water and was acidified with dilute aqueous HCl to give a cream colored precipitate. The precipitate was collected by filtration and washed with water. Crystallization from hot methanol gave 20.6 g l,2-bis(acryloyloxy)tetrabromobenzene (66% yield) as fine, colorless needles. The product had a melting point of 135-37°C.
• liquidified monomers or monomer mixtures
• a photoinitiator preferably
• PhC(O)CH(OCH CH 3 ) 2 (DEAP), syringe-filtered, deoxygenated and exposed to UV radiation from an OrielTM 50 watt mercury arc lamp or a Sylvania Blacklight fluorescent bulb (Sylvania 350BL bulbs, Siemens Corp./Osram Sylvania Inc., Danvers, CT) for 30-60 minutes.
• OrielTM 50 watt mercury arc lamp or a Sylvania Blacklight fluorescent bulb Sylvania 350BL bulbs, Siemens Corp./Osram Sylvania Inc., Danvers, CT
• the samples were typically heated to temperatures above their glass transition temperature during and after light exposure to ensure an acceptable extent of curing. Heating was effected either with an IR heat lamp or in a convection oven.
• average abs/cm was the average light absorption per centimeter over the wavelength region noted.
• the target value was ⁇ 0.01.
• TMPTA l,l,5,5-tetrahydrohexafluoropentane-l,5-diol diacrylate
• TFHQDA tetrafluorohydroquinone diacrylate
• Polymer films approximately 0.05 mm thick, were prepared from the mixtures by placing the monomer solutions between polycarbonate release liners that were then warmed to
• FPEGDA perfluorocyclohexyl
• CH 2 CHCOOCH 2 (CF 2 OCF 2 )l
• CH 2 OCOCH CH 2 , n ⁇ 6-12 made by J acrylation of the diol prepared as in US 5,384,374 by direct fluorination of diacetate of poly(ethylene glycol) (av. No. molecular wt of -600), methanolysis, and reduction with NaBH4. Because of its high molar volume, FPEGDA had very low optical loss in the infrared regions of interest. Polymer films were tested as above for swelling by pentafluorophenyl acrylate and the data are shown in Table 3B.
• Halogenated acrylates of the invention include those based upon the reaction of acryloyl chloride with: 1) perhalogenated tertiary carbinols, 2) perhalogenated phenols, and 3) perhalogenated naphthols; and 4) perhalogenated thiophenols.
• Haloacrylates described in Table 4 were prepared according to methods described in Examples 2, 3, 7, 8, 9, and 11. Their structures were confirmed by spectroscopic analysis.
• Haloacrylates described in Table 5 were prepared according to methods described in Examples 4, 5, 6, and 10. Their structures were confirmed by spectroscopic analysis.
• a perfluorothioacrylate co ⁇ esponding to formula XXXI was prepared in a manner essentially as described previously by reaction of acryloyl chloride with pentafluorothiophenol (c.f, Examples 1, 5, 6, etc.).
• Compound XXXI had a melting point of less than 25° C, and the refractive index (n 1 IV ) of the co ⁇ esponding homopolymer was 1.516.
• Example 17 Preparation of tribromopyrogallol triacrylate (Compound XXV) Pyrogallol (10 g) was dissolved in 150 mL of diethyl ether and bromine (12 mL in 50 mL of dichloromethane) was added dropwise over a 2 hour period to the stirred solution. The resulting reddish homogeneous solution was sti ⁇ ed for 16 hours. The reaction mixture was then rotary evaporated to a light red-brown semicrystalline solid. The solid was dissolved in 200 mL of diethyl ether and the solution was filtered. Heptane (200 mL) was added to the filtrate and the slightly cloudy solution was allowed to slowly evaporate to form fine, off-white needles of tribromopyrogallol (27.7 g, 96%).
• Example 18 Preparation of tribromophloroglucinol triacrylate (Compound XXIV) Phloroglucinol dihydrate (10 g) was suspended in 150 mL of dichloromethane and bromine (12 mL in 50 mL of dichloromethane) was added dropwise over 2.5 hour period to the sti ⁇ ed suspension. The suspended phloroglucinol dissolved during the course of the bromine addition. After stirring for an additional 2 hours a two-phase solution was obtained. The pale orange dichloromethane supernatant solution was decanted from a small amount of a denser, dark red aqueous solution. The dichloromethane solution was rotary evaporated to a pinkish colored semicrystalline solid.
• Example 19 Use of brominated crosslinkers to modify the refractive index of hydrocarbon acrylates Tetrabromocatechol diacrylate (Example 12) (1.0019 g) was dissolved in 3.9905 g phenoxyethyl acrylate (PEA) (CPS Chemical Co., Old Bridge, NJ) to give a solution containing approximately 20% by weight of the diacrylate crosslinker. Tribromophloroglucinol triacrylate (Example 18) (0.4995 g) was dissolved in
• refractive indices were calculated for the homopolymers derived from the brominated crosslinkers.
• a refractive index at 1.31 nm of 1.693 was calculated for polymerized tetrabromocatechol diacrylate and a refractive index at 1.31 nm of 1.628 was calculated for polymerized tribromophloroglucinol triacrylate.
• This example shows that the brominated crosslinkers can be used to crosslink acrylate monomers and that they are effective in increasing the refractive index of the resulting polymer.
• Example 20 Use of brominated crosslinkers to modify the glass transition temperatures (Tg) of hydrocarbon acrylates Tetrabromocatechol diacrylate (Example 12) (0.5084 g) was dissolved in 4.5006 g isobornyl acrylate (IBA) (San Esters Corp., NY) to give a solution containing approximately 10% by weight of the diacrylate crosslinker. Tribromophloroglucinol triacrylate (Example 18) (0.5051 g) was dissolved in 4.4952 g BA to give a solution containing approximately 10% by weight of the triacrylate crosslinker. DEAP photoinitiator (0.2% by weight) was added to the solutions and to a sample of pure IBA.
• IBA isobornyl acrylate
• DEAP photoinitiator (0.2% by weight
• the Tg of polymerized IBA was found to be 62.5 °C.
• the Tg of IBA copolymerized with 10 wt% tetrabromocatechol diacrylate was found to be 98.5 °C.
• the Tg of IBA copolymerized with 10 wt% tribromophloroglucinol triacrylate was found to be 96 °C.
• Example 21 1 -( 1 ,2,2-trichloro- 1 ,2-difluoroethoxy)perfluoroacetone
• the acetate was taken up in perfluoro N-methyl morpholine (PNMM, 3M Company, St. Paul, MN) and subjected to direct fluorination, as described in the previously- incorporated Example 1 of U.S. Patent No. 5,236,919.
• the fluorinated ester was converted to the co ⁇ esponding methyl hemi-ketal by addition of BF /MeOH, and the hemi-ketal was converted to the desired ketone by distillation from cone.
• Example 29 4-Pentafluorobenzoyloxy-2,3,5,6-tetrafluorophenyl acrylate
• the MgSO -dried extract was stripped on a rotary evaporator to give 48.6g of tan liquid, 92% C F OtBu and 4% di-t-butoxytetrafluorobenzene isomers by GC. Of this, 42.4g was sti ⁇ ed at 60° for 22 hr with 25. Og powdered KOH in 65 mL t-BuOH.

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=25359127

Family Applications (1)

Country Status (8)

Cited By (6)

Families Citing this family (59)

Citations (9)

Family Cites Families (19)

• 1997
  • 1997-06-10 US US08/872,235 patent/US6005137A/en not_active Expired - Fee Related
  • 1997-09-29 DE DE69732310T patent/DE69732310T2/de not_active Expired - Lifetime
  • 1997-09-29 JP JP50235299A patent/JP4065932B2/ja not_active Expired - Fee Related
  • 1997-09-29 EP EP97909884A patent/EP1009729B1/en not_active Expired - Lifetime
  • 1997-09-29 AU AU47392/97A patent/AU4739297A/en not_active Abandoned
  • 1997-09-29 KR KR1019997011592A patent/KR100597970B1/ko not_active IP Right Cessation
  • 1997-09-29 CN CN97182296A patent/CN1125030C/zh not_active Expired - Fee Related
  • 1997-09-29 WO PCT/US1997/017437 patent/WO1998056749A1/en active IP Right Grant
• 1999
  • 1999-08-23 US US09/379,156 patent/US6313245B1/en not_active Expired - Fee Related
  • 1999-08-24 US US09/382,300 patent/US6288266B1/en not_active Expired - Fee Related
• 2001
  • 2001-05-01 US US09/846,739 patent/US6362379B2/en not_active Expired - Fee Related

Patent Citations (9)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events