A manifold has one or more inlets and one or more outlets. An elongate hollow core of the manifold is divided longitudinally into a plurality of lumens by one or more elongate partitioning members extending across the manifold core to enable flow of the liquid to be directed laterally around the manifold from the or each inlet to the or each outlet. A gated valve gated assembly is adapted for use with a beverage distributing manifold having a plurality of longitudinally separate lumens. The valve assembly includes a hollow body having an inlet and an outlet for the passage of liquid therethrough to a distribution port. The valve body is transversely movable within and across the manifold to separately locate the inlet in each lumen.

1. Field of the Invention
This invention relates to improvements for manifolds used in the drinks industry, particularly but not exclusively for the distribution of beverages.
2. Description of Prior Art
One form of multiple beverage distribution is a dispense tower having a number of branch outlets connectable to the taps to supply the same or different drinks to each tap. Where the drinks have the same major constituent, e.g. still or carbonated water, this is supplied to all the outlets through a common manifold.
As shown and discussed in GB-A-2271619, a standard manifold has poor flow characteristics, creating pockets of possible stagnation of water therein, and unequal pressure delivery across the outlets. The invention in GB-A-2271619 is a xe2x80x98tube-in-tubexe2x80x99 manifold designed to create a better equalising flow across the outlets by directing the flow around the manifold between the inlet and outlet delivery lines. However, manufacture of the usually metallic tube-in-tube manifold requires the separate formation of the tubes, conjunction of the tubes, and the creation and addition of extra dimples to hold and centralise the inner tube in place. Manufacture is not therefore simple or flexible.
An object of the present invention is to achieve the same or a similar effect as the tube-in-tube manifold, but with significantly easier manufacture.
According to one aspect of the present invention, there is provided a manifold having one or more inlets and one or more outlets, wherein the elongate hollow core of the manifold is divided longitudinally into a plurality of lumens by one or more elongate partitioning members extending across the manifold core to enable flow of the liquid to be directed laterally around the manifold from the or each inlet to the or each outlet.
By dividing the manifold longitudinally along its core, liquid can be directed laterally from one end to the other, or at least along and across the apertures for any branch outlets, avoiding stagnation and equalising distributing temperature and pressure.
The partitioning member(s) may be separate or integral with the manifold, preferably supported in place by the manifold body wall, either directly or with intermediate supporting means. Where separate, the partitioning member(s) could be readily and easily insertable into one end of the manifold which is then sealed. A separate partitioning member would preferably be supported in place across the core by interference fit the manifold wall, although loose or looser fitting could be used for certain applications.
Preferably, the partitioning member(s) are formed integrally with the main body of the manifold, e.g. by plastics extrusion. Thus according to a second aspect of the present invention, there is provided a manifold whose elongate hollow core is divided longitudinally into a plurality of lumens by one or more partitioning members extending across the manifold, wherein the body of the manifold and the or each partitioning member are integrally formed by plastics extrusion. The partitioning member(s) are then inherently supported in place by the manifold body wall (s). The ends of the manifold body can then be sealed eg. using end caps
More preferably, the manifold uses one partitioning member, which, depending upon its shape is able to divide the manifold core into two, three, four or more lumens.
Each lumen may be separate from each other lumen, or be able to direct liquid flow into one or more other lumens through common passages. Where the manifold includes two or more separate lumens or sets of lumens, each separate lumen or each set of lumens will have a separate inlet and outlet. More than one inlet and/or more than one outlet may be used for each lumen or each set of lumens.
The partitioning member(s) may include slits, perforations or other apertures therein to increase or disturb the flow of liquid to and/or around the neighbouring lumen(s). The partitioning members) may extend wholly or substantially along the length of the manifold core. Where a partitioning member extends only substantially along the length, liquid can flow into one or more other lumens within the remaining common passage in the core. Where a partitioning member extends to the ends of the manifold core, and the passage of liquid to one or more other lumens is desired, apertures can be created in the one or both ends of the members, or one or both ends of the members can be cut away, to allow such flow.
Most liquid circulating manifolds have one delivery inlet and one delivery outlet. Whilst in the present invention, an inlet and a corresponding outlet could be coupled to the same lumen, with possibly a barrier in the lumen therebetween to prevent direct inlet to outlet flow, the manifold preferably has one inlet coupled to one or more lumens, and one outlet coupled to at least one different but connected lumen.
The inlet(s) and outlet(s) could also be positioned anywhere around or along the manifold, either separately or neighbouring. Preferably, the or each inlet and the or each corresponding outlet are neighbouring and parallel.
According to one embodiment of the present invention, the manifold has one inlet and one neighbouring and parallel outlet, and a partitioning member integrally formed across and substantially along the length of the manifold core to create two lumens with connecting ends, wherein the inlet is coupled to one lumen and the outlet is coupled to the other lumen.
The manifold may be used to distribute a beverage to a plurality of branch outlets, apertures to which are spaced in the manifold body along the side of one lumen. The term xe2x80x9cbeveragexe2x80x9d as used herein includes a beverage component used to create a vendible beverage, e.g. still water, carbonated water, etc.
The manifold may also be used to circulate a coolant around the manifold to cool the surrounding environment, neighbouring components and/or neighbouring liquids. Such cooling includes trace cooling of any adjacent supply lines, and conduction cooling of the beverage dispensing heads or taps through the use of metal blocks or ferrules thereinbetween. The dispensing heads or taps preferably attach or connect directly with the metal blocks or ferrules, and the blocks or ferrules fit wholly or substantially around the manifold.
The manifold of the present invention has a further advantage, in that it can be sized to conveniently fit into the existing housings and shells of drinks-dispensing apparatus such as towers. This is particularly so for the internally divided cooling manifold as herein described, which can be considerably more compact and convenient to fit and use for the same amount of cooling than the single-bore cooling tubing currently used, which has to be bent into a T-shape with consequent space and flow problems.
Thus, according to a third aspect of the present invention, there is provided an is integral tower cooling assembly comprising an internally divided cooling manifold and one or more conjoined metal ferrules adapted to connect with and supply cooling to one or more dispensing taps, the manifold and the or each ferrule being held together by a rigid insulative surround.
Such a cooling assembly could be immediately ready for installation into a tower housing, requiring no further fittings or connections therewithin. The internally divided cooling manifold may have any suitable arrangement, eg. as shown in GB-A-2271619. Preferably, the cooling manifold is divided longitudinally into a plurality of lumens as herein described.
According to a fourth aspect of the present invention, there is provided a gated valve assembly adapted for use with a beverage distributing manifold having a plurality of longitudinally separate lumens, wherein the valve assembly includes a hollow body having an inlet and an outlet for the passage of liquid therethrough to a distribution port, the valve body being transversely moveable within and across the manifold to separately locate the inlet in each lumen.
The gated valve assembly allows the separate passage of the liquid in each lumen to the outlet of the valve body, and hence to the distribution port. One manifold can thus supply two or more different beverages, and the supply to each distribution port can be altered as desired or necessary.
The inlet of the valve body is preferably smaller than the transverse width of each lumen. The inlet may also be smaller than the separation between the lumens, to prevent any flow between the lumens when moving the valve body. Alternatively, the inlet is sized and/or shaped so as to allow the passage of liquid from two or more lumens simultaneously.
The valve assembly is preferably supported by housing on one or both sides of the manifold. The distribution port could be coupled to the housing, and the housing could support and guide movement of the valve body.
In one embodiment of the gated valve assembly, the manifold is divided longitudinally by one or more elongate partitioning members across the manifold core to create the lumens as described hereinbefore.
The manifold and gated valve assembly may be made from any suitable material or combination of materials. Preferably, the manifold and gated valve assembly are made of plastic, e.g. a mouldable plastic such as thermoplastic, more preferably polyethylene. The plastic components can be welded together using known welding techniques. A plastic material is preferred in view of its cheapness, flexibility, and ability to be extruded, e.g. to form the main body of manifold as one piece.


Solvent-free and water-free radiation-curable primers based on hydroxy-functional prepolymers and cycloaliphatic epoxides or based on hydroxy-functional prepolymers and olefinically unsaturated compounds or based on epoxides and vinyl ethers together with cationic or free-radical initiators may be applied in the same manner as conventional commercial solvent-free laminating adhesives and, for many coatings, allow subsequent in-line coating without there being any need to evaporate solvent or water from the primer coating.

1. Field of the Invention
This invention relates to primer compositions which are solvent-free and contain cationically and/or free-radically curable crosslinking systems and to the production and use thereof.
2. Discussion of Related Art
Coupling agents (primers), which make it possible for the coating to adhere to the substrate or distinctly improve adhesion, are used in many coatings. Primers are used on difficult to coat substrates, for example when coating flexible support materials (films) and rigid support materials. In particular, primers are used when coating these materials with polyvinylidene chloride (PVDC), hot melts (hot melt adhesives), heat sealing lacquers, silicone, printing inks and lacquers, metallisation and extrusion coating/extrusion lamination with polyethylene (PE) or polypropylene (PP).
According to the prior art, primer compositions containing solvents are used in such coatings, with the primer compositions, for example, containing moisture-curing polyurethane prepolymers as the reactive component in addition to the solvents. While these primer compositions containing solvents do indeed very adequately fulfil the technical requirements placed upon them, costly recirculation or incineration plants are necessary due to today""s stringent environmental requirements relating to the prevention or minimisation of volatile organic solvent emissions.
In recent times, many aqueous dispersions or solvents have thus been proposed for this purpose. DE-A-4408487 thus describes an aqueous polyurethane primer composition consisting of a dispersion of an OH-functional polyurethane prepolymer and an isocyanate component. This primer composition is suitable for PVC products, especially for PVC profiles, for laminating PVC, polyether sulphone, polyolefin or polymethacrylate films with plastics products, in particular in conjunction with the use of (reactive) hot melt adhesives. These primer compositions fulfil the requirement of the absence of organic solvents, but considerable effort must be expended to dry the aqueous primer layer when it is applied in large areas in high speed coating machines. A further difficulty with temperature-sensitive substrates is that high drying temperatures cannot be used, such that short drying or flashing-off times are virtually impossible to achieve with aqueous systems.
The object thus arose of providing a primer composition which is both substantially free of volatile organic solvents and free of water as a solvent or dispersant and which is suitable for providing a coupling coating when coating temperature-sensitive substrates of the above-stated type. Such a primer composition should fulfil the following requirements:
be substantially free of organic solvents and/or water,
have a processing temperature of below 150xc2x0 C., preferably of below 100xc2x0 C.,
have a processing viscosity of below 5000 mPaxc2x7s at the processing temperature,
primer application rates of substantially less than 5 g/m2 should be possible on conventional processing plant,
the coupling agent layer should exhibit elevated cohesion and low surface tack,
both xe2x80x9cin-linexe2x80x9d priming and xe2x80x9coff-linexe2x80x9d priming should be possible.
xe2x80x9cIn-linexe2x80x9d priming is taken to mean that, after coating with the primer composition, a further coating is applied onto the primer layer in a single operation. In xe2x80x9coff-linexe2x80x9d priming, the primer is first applied and a further coating applied at a later time.
This object has been achieved according to the invention by the provision of solvent-free, radiation-curable compositions which are applied in the same way as conventional commercial solvent-free laminating adhesives, wherein according to the invention these compositions have a viscosity of below 5000 mpaxc2x7s at temperatures of below 100xc2x0 C. According to the invention, immediately after application of the primer, the molecular weight of the composition is dramatically increased by UV irradiation or electron beam irradiation. Coating may then proceed in a single operation (in-line) or in two operations (off-line) with intermediate winding of the substrate web onto a reel. In the case of the off-line method, the primer must not have any surface tack during winding, so avoiding adhesion onto the reverse side of the support, as the roll of the web material would otherwise block.
The radiation-curable primers may be cured cationically, free-radically or by a combination of both polymerisation mechanisms (hybrid systems).
Radiation-curable polymer systems based on cycloaliphatic epoxides are known in principle. The company literature Cyracure, Cycloaliphatic epoxides from Union Carbide Chemicals and Plastics Co. Inc. thus describes cationic, UV-curable binder systems based on mixed cycloaliphatic epoxides, polycaprolactone diols, reactive diluents based on aliphatic or cycloaliphatic epoxides together with triarylsulphonium hexafluorophosphate salts or triarylsulphonium hexafluoroantimonate salts as the photoinitiator. Stated applications are lacquers for cans and lids, decorative metal coatings, lithographic printing inks, paper coating and the like. This company literature makes no mention of the applicability of such compositions as primers for the purposes of the present invention.
Free-radically curing systems, which cure in the presence of a photoinitiator after UV irradiation or without a photoinitiator after electron irradiation, are also known in principle. EP-A-326917, for example, thus describes adhesive mixtures which contain a polyurethane polymer containing hydroxyl groups and having a molecular weight of preferably 100000 to 300000, photopolymerisable, ethylenically unsaturated compounds, optionally a photoinitiator and conventional adhesive auxiliaries (surfactants, adhesion promoters, tackifiers). These adhesive mixtures are radiation-curable and thermally activatable. These compositions are suitable for use as adhesives for adhesive bonding of plastics materials, no mention being made as to their suitability as a coupling agent coating for difficult to coat substrates.
Hybrid systems, which cure by a combination of cationic and free-radical polymerisation, consist, for example, of vinyl ethers and acrylate oligomers and contain both a cationic and a free-radical photoinitiator. Such hybrid formulations are described, for example, in the company literature Rapid Cure Hybrid Formulations for High Humidity Environments from the company International Specialty Products. Stated applications are as UV-curable clear lacquers for paper, plasticised PVC, polycarbonate and polyester.
Radiation-curable compositions based on epoxy compounds, hydroxy-terminated polyurethane polymer and a photoinitiator and the use thereof as a laminating adhesive are described in U.S. Pat. No. 5,328,940. The teaching of U.S. Pat. No. 5,328,940 makes no disclosure in relation to solvent-free, radiation-curable primer compositions.
The free-radically curing primer compositions according to the invention are based on styrene, acrylate and/or methacrylate monomers, optionally in the presence of acrylate- or methacrylate-functionalised prepolymers.
Examples of preferably used ethylenically unsaturated components of the above-stated type are butyl, hexyl, ethylhexyl, dodecyl, dicyclopentadienyl, hydroxyethyl, 2-hydroxypropyl, 4-hydroxybutyl, 2-methoxyethyl, 2-ethoxyethyl-2-(2-ethoxyethoxy)ethyl, tetrahydrofurfuryl acrylate, N,N-dimethacrylamide, ethylene glycol diacrylate, butanediol diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate and the corresponding methacrylates, optionally vinylpyrrolidone and divinylimidazole.
Possible further constituents of these free-radically curing systems are hydroxy-functional polyurethane prepolymers which are produced in a manner known per se from polyether polyols or polyester polyols and diisocyanates with a stoichiometric excess of the OH component.
In the event of curing by UV light, these primer compositions additionally contain suitable photoinitiators, for example benzoin, benzoin methyl ether, benzoin isopropyl ether, benzophenone, Michler""s ketone, 2-hydroxy-2-methylpropionphenone, benzil dimethyl ketal, acetophenone, xcex1,xcex1-dimethoxyacetophenone or similar compounds.
The molecular weight of the OH-functional polyurethanes and the ratio of generally low-viscosity and ethylenically unsaturated components must here be adjusted relative to each other such that the processing viscosity at the processing temperature remains distinctly below 5000 mpaxc2x7s. Especially in the case of off-line priming, care must additionally be taken to ensure that the primer layer no longer exhibits any surface tack after irradiation.
Due to their low sensitivity to oxygen, cationic systems or hybrid systems are particularly preferred for the radiation-curable primer compositions according to the invention. Cationic systems are here prepared on the basis of cycloaliphatic polyepoxides and optionally aliphatic or cycloaliphatic epoxides as reactive diluents, hydroxy-functional polyesters and/or hydroxy-functional polyurethanes and suitable photoinitiators.
Examples of suitable cycloaliphatic epoxides are the epoxides of cycloaliphatic esters of dicarboxylic acids, such as bis-(3,4-epoxycyclohexylmethyl) oxalate, bis-(3,4-epoxycyclohexylmethyl) adipate, bis-(3,4-epoxy-6-methylcyclohexylmethyl) adipate, bis-(3,4-epoxycyclohexylmethyl) pimelate. Further suitable diepoxides of cycloaliphatic esters are described, for example, in U.S. Pat. No. 2,750,395.
Further suitable cycloaliphatic epoxides are, for example, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, bis-(3,4-epoxycyclohexyl) adipate, 3,4-epoxy-1-methylcyclohexylmethyl-3,4-epoxy-1-methylcyclohexane carboxylate. Further suitable cycloaliphatic epoxides are described, for example, in U.S. Pat. No. 2,890,194.
Reactive diluents which may be used are either mixtures of low viscosity cycloaliphatic epoxides or preferably 1,2-epoxyalkanes, such as for example 1,2-epoxyhexadecane or the monofunctional glycidyl ethers of alkanols.
Polyols which may be used are per se known OH-functional polyesters based on aliphatic or aromatic dicarboxylic acids and low molecular weight glycols, for example polyesters based on adipic acid, sebacic acid, isophthalic acid and glycols such as ethylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, hexanediol and the like. Hydroxy-terminated polycaprolactones known per se may also be used.
Further OH-terminated prepolymers may be the per se known reaction products of polyether polyols and/or polyester polyols and diisocyanates, provided that the molecular weight is low enough in order to ensure a low viscosity primer composition.
Photoinitiators which may be used are in principle any so-called xe2x80x9coniumxe2x80x9d salts, as described, for example, by F. Lohse and H. Zweifel in Adv. Polym. Sci. 1986, pp. 61-81. The mixed triarylsulphonium hexafluoroantimonates and the mixed triarylsulphonium hexafluorophosphates are in particular preferred, as are commercially available, for example, under the name Cyracure from Union Carbide.

Solventless primers which are hardenable by radiation


A tear-duct drain includes a hollow rigid tube which is elongated and has a first flange at one extremity thereof. A flexible, resilient and collapsible second flange is bonded to the tube at a predetermined distance away from, and so providing a leading edge at, the opposite extremity of the tube.

In healthy individuals, tear fluid (that is "lacrimal" fluid) is normally supplied continuously to their eyes from lachrymal glands, each being located in a lateral and superior relation to the respective eye. Upper lacrimal ducts feed the fluid from each gland to a respective conjunctival sac, in which the relevant eyeball is partially encased. The lacrimal fluid subsequently washes the sclera and other conjunctival components of the eye, as well as its cornea.
Under such healthy conditions, excess lacrimal fluid that cannot be retained by each eye and conjunctiva tends to be drained (see FIG. 1 of the drawings accompanying this specification) from the inner-canthus 1 (at the corner of the eye) to the nasal passages 7a, b, in particular to the inferior nasal meatus 7b.
After any excess fluid has drained from the inner-canthus 1, it passes through a network of passages commencing with the puncta, which are seen as small papillae 2, 3 adjacent to the inner-canthus 1. From here, the lacrimal fluid is subsequently collected in the lacrimal sac 6, which is connected to the puncta via a number of canaliculi 4, 5. The lacrimal fluid is thereafter drained through the nasolacrimal duct 8 into the interior meatus 7b of the nose.
Sometimes, if an unwanted closure of the passageways of the system occurs, for example by way of a blockage of any one of its sub-components, excess lacrimal fluid can no longer be disposed of in the usual way. Such a blockage can result from, inter alia, congenital anomalies, accidents, inflammation, advancing age, and so forth, and tends to cause the eye to continuously brim over with tears, with concomitant discomfort to the individual.
More seriously, if the blocked tears stagnate, they can become infected, which can then lead to inflammatory irritation of the mucous membranes of the affected passage. In turn this can result in proliferation of local epithelium, as well as hyperaemia, and even a purulent exudation into the conjunctiva. Infection caused in this way can ultimately lead to scarring over of the canaliculi 4,5.
In severe cases, the resultant permanent closure can require a corrective surgical procedure known as a dacryocystorhinostomy (DCR). In some of these cases, only the defective portion of the lacrimal drainage system needs to be reconstructed. Thus, if the sole blockage occurs in, for example, the nasolacrimal duct, the latter can be removed, and the remaining lacrimal sac cavity can then be joined directly with the mucosa of the nasal fossa. This is typically achieved by removing tissue, including the intervening segment of nasal bone and periosteum, so that the drainage of tear liquid into the nose can be more or less restored.
In many other cases, however, removal of the entire lacrimal drainage system may be necessary, the insertion of a replacement mechanical device (for example a tube) then being required. Such operations have to date seldom been entirely successful, because at least the following two particular difficulties have typically been experienced.
Firstly, as the nasal bone heals around the lower end portion of the inserted replacement tube, the latter is gradually rejected from the bone and flesh of the patient. And secondly, the patient's flesh also tends to heal over the external end of the replacement tube at the inner-canthus 1, which therefore requires appropriate surgical reopening from time to time.
Conventionally, the replacement tube utilised in tear-duct surgery has been a small tube constructed of Pyrex™ glass, stiff plastic or some other relatively rigid material. However, usually it is Pyrex™-type glass that has been preferred, since this can neither be destroyed, nor corroded or otherwise affected by a patient's bodily fluids.
These tubes of Pyrex™ glass are generally known by surgeons as "Lester Jones" tubes, being named after their designer, Mr Lester T Jones, and are sometimes simply referred to as "Jones" tubes. Very similar devices go by the alternative trade names "Callaghan Cox", "Gladstone Putterman", "Baylis", and "Naugle" tubes. These replacement tubes have a typical length of the order of about 18 mm and, as such, are inserted into the inner corner of the eye, and then down the surgically created passage, so as to allow the drainage of the excess lacrimal fluid internally into the nose.
Despite their rigidity, the main flaw of these replacement Jones-type tubes is that, as described above, they usually tend to be worked out of their in situ position by the action of the patients' own bone and flesh. They are therefore at risk of being completely lost either by descending into the nasal passage or by ascending into the eye. In either eventuality, the function of these replacement tubes is of course utterly negated, consequently necessitating the inconvenience and cost of one, or more, further corrective operations.
In addition, double-flanged Jones-type tubes have also been previously made available. These have two opposing flanges at either end of a hollow shank, with the aim of attempting to prevent their rejection. However, these tubes tend not to be particularly effective either since, in practice, they have at least the following extra disadvantages:                a) The relatively larger diameter of their additional leading (internal) flange of rigid glass, as compared to that of their hollow shank, means that these tubes are relatively very difficult to place in situ. This is because the surgically created passage is more difficult to open and traverse by a large leading flange.        b) Further, a large leading flange requires either a correspondingly larger surgically passage to be created before the tube's insertion, or if the flange is pushed through an otherwise smaller passage, damage to the tissue surrounding the passage is likely to create a larger diameter through the passage. Hence, when the tube has been placed in situ, its shank will be inherently less stable.        c) The diameter of the rigid internal flange is nevertheless still relatively small compared to that of the passage after its insertion and so little barrier to the extrusion of the in situ tube is thereby provided.        d) This leading flange is furthermore positioned at a relatively sub-optimal site along the shank, being right at its internal tip and, therefore, after insertion the orifice at this tip is prone to blockage by the normal growth of the nasal mucosa that closely surrounds it.
Other prior devices include those as follows:
FR-A-2, 813, 522 (see FIGS. 2 and 3 accompanying the present specification) discloses the use of a tubular lacrimal drain 11, 12 having one or more parts, one of which is an internal fixing unit. This allows anchoring of the drain 11,12, typically by providing a screw-threaded attachment means 10, 12a.
CN-A-1, 650, 824 also provides an artificial tear duct, in this case being in the form of a spiral spring-like structure, typically used as a temporary stent to allow scar tissue to become stable before the spring is softened and thereafter pulled out as an unravelled metal wire.
U.S. Pat. No. 5,062,831 (see FIGS. 4A-C accompanying this present specification) discloses the use of a solid tubing 16, having no lumen, for temporarily removing excess lacrimal fluid by capillary action. A conventional DCR is performed, by removing adjacent bone so that the remaining sac communicates with the internal nasal meatus 7. A catheter 13, with enlarged portions 15 at either end of an elongate shank portion 14, is used simply as a temporary stent to prevent scarring over of the newly opened hole between the sac and the nose.
This procedure, whilst being a suitable treatment for nasolacrimal duct 8 obstruction, cannot assist canalicular 4, 5 obstruction surgery. This is, firstly, because no external opening on the corner of the patient's eye is made. And, secondly, even if it were to be made, the internal opening created by the DCR is kept overly large by the similarly large diameter of the catheter's shank portion 14, which in any case creates a degree of instability. Understandably, the use of such a catheter 13 is taught purely as being a temporary measure.
JP-A-2004-230, 012 (see presently accompanying FIGS. 5A-C) discloses a tear duct stent 17 that has enlarged portions (or collars) 18; 19a, 19b at either end of a tube 20. Hence, this stent is similar in shape to the above-described double-flanged Jones tube, but because this stent is formed of a soft material, the length of its tube can be adjusted as required by cutting it with scissors. Further, having been placed in situ, one or more of its collars may subsequently be cut away to allow the remainder of the stent to be pulled and so removed.
Because of its enlarged ends, insertion of the device can again be problematic, as with the double-flanged Jones-type tubes. Also, the creation of a tissue passage lumen of relatively larger diameter 21 than that of their tube itself may occur, so that in situ instability can once again be a problem.
Moreover, temporary removal of these stents does not appear to be possible, and is not taught in JP-A-2004-230, 012. Indeed, its teaching appears to suggest that the device 17 can be constructed in situ, for example by bonding either (or both) collars 18; 19a, 19b to an already inserted tube 20. Even this would seem to be manually difficult and, potentially, impractical.
The present invention aims to provide an improved device for correcting tear-duct obstructions and, in particular, for the correction of canalicular obstructions. The latter have previously tended to be even less successfully treated than blockages of other tear-duct system parts.
The device of the present invention has the advantages that it can be more accurately placed in situ and with greater ease than previous devices, as well as being able to be left more stably in situ afterwards. This befits the relatively more permanent correction that it can provide, if such permanency is required.
Potentially permanent devices of this type also need to be easily removeable, at least temporarily, so that they can be cleansed along with the patient's consequently vacated tissue passageway. This helps to avoid, for example, microbial contamination, so that tissue damage resulting from inflammation is less likely to occur. If left unchecked, however, such damage would tend to increase the likelihood of rejection of the device from the patient.
The elongated tube of each of these improved devices may be made of any suitably inert material that promotes a high level of biocompatibility with patient tissue, as well as the preferred ease of cleaning the device as a whole upon its temporary withdrawal.
Whilst the tube of the present device has a first enlarged external portion at one end that is designed to act as an anchor at the corner of the patient's eye, it also has a collapsible second flange that is preferably positioned towards the opposite end of the tube. Because of its resilience and, typically, relatively large diameter, this second flange tends to prevent the device from slipping. This is because it helps to secure the tube in its in situ position, and so stabilise it against any forces (for example during sneezing of the nose or blinking of the eye) that it might experience thereafter. This is effected by the opening-up of the flexible flange inside the patient's nose and its subsequent positioning against the nasal mucosa around the internal opening of the tissue passageway.
Preferably, the flexible material of which the collapsible second flange is constructed has a relatively much smaller dimension of thinness compared to that of the diameter of the elongate tube. As such, when the device is being inserted, or being temporarily withdrawn, this second flange is consequently encouraged by the surrounding tissue of the passageway to flex. Thus, it can lie flush against the body of the tube, and to the appropriate side of the site of its bonding to the tube, depending upon the relative direction of movement of the tube.
This helps to reduce as much as possible any increase in effective total diameter that is presented by the drain, in terms of the combined cross-section of both its tube and its flush second flange, as it is passed through the patient's tissue. In particular, the tube may be indented on either side of the site of bonding to provide recesses (in the tube's surface) that can accommodate the second flange when flexed.
During the device's insertion, and any temporary withdrawal, the risk of either damage to the device, or traumatisation of the patient's tissue, can thus be minimised. Removal of the device, as frequently as is needed, is facilitated therefore allowing it to be cleansed according to each patient's needs. No matter how often such removal is performed, damage to tissue is minimised, which in turn helps to maximise the long-term stability of the device when it is left in situ.
The tear-duct drain 21 shown in FIG. 6A has a first flange 28 at the external (that is, inner-canthal) opening 23 of its tube 24. A second flange 25 is also provided and is positioned close to—but not at—the internal (that is, nasal) opening 26 of the leading edge 27 of the tube 24.
Preferably, the tube 24 and first flange 28 are composed of a rigid material, for example a glass or a plastics material. Glass is generally a preferred material, since it has excellent capillary characteristics and is very biocompatible.
The relative dimensions, and relative resilience, of the second flange 25 are predetermined to allow the tube 24, when in situ, to be stable to any potentially destabilising forces that might otherwise cause either its movement inwards into the nose or outwards towards the eye. Patients are therefore provided with a significant safety benefit to their eyes. Complete loss of the device 21 is also reduced.
The relative resilience of the second flange 25 can be defined in terms of the degree of the relative shear forces involved. That is, for example, the maximum shear force that the flange 25 can withstand before it collapses; and, the respective minimum that it can overcome before it bounces back into shape.
The flexibility of the second flange 25 also ensures that it can collapse in both directions. That is, both: (i) towards the external end 28 of the tube 24 [a "first flush position"]; and, (ii) towards the leading edge 27 of the tube 24 [a "second flush position"]. The position adopted depends upon the direction in which the tube is being urged by the surgeon.
The second flange 25 can thus adopt the first flush position during the tube's insertion (that is, in direction I, as shown in FIG. 6B). Once the internal end of the tube 24 reaches the space just beyond the entrance to the inside of the nose, the resilience of the second flange 25 enables it to spring open. Thus, somewhat in the manner of an umbrella, it can change its configuration from being folded into being in an open position. This springing open can if necessary be facilitated by the surgeon, for example by applying a degree of manual pressure against the elasticity of the tissue area surrounding the nasal (inner) orifice of the lumen of the passageway, so as to aid release of folded flange into nasal meatus 7.
Subsequent fixing of the tube 24 into its secured, in situ position is encouraged by the resilient nature of the opened internal second flange 25 and its typically substantially larger diameter, as compared to that of the inner orifice. This is further encouraged when the device 21 is slightly withdrawn back towards the eye (that is, in the opposite direction to direction I in FIG. 6B), so that the second flange 25 abuts against the tissue surrounding the inner orifice.
Moreover, maintenance of this secure fixing is also encouraged by minimising any potential increase in the diameter of the passageway, that might otherwise be caused by trauma to the patient's tissues both during initial placement and during temporary withdrawal of the device (in direction II as shown in FIG. 6D). This is achieved by ensuring that the thickness 29 of the flange 25 is relatively small compared to the cross-sectional diameter 30 of the tube 24. In other words, by minimising the total cross-sectional diameter of the device 21 with the second flange 25 collapsed in its first flush position.
As shown in FIGS. 7A-D, such minimisation can optionally be achieved by adapting the tube's shape to include indentations on either side of the bonding site of the second flange, which can therefore adopt the flush positions by collapsing into and thus being held in the recesses (for example, 31) so created.
The collapsible flange is typically bonded to the inert material of the tube 24 by a suitable adhesive. For example, any glue that can bond potential collapsible flange 25 material, such as silicone, to the material of the tube 24, for example glass, can be used. The chosen glue should also preferably be able to withstand high temperatures for autoclaving, as well as being generally tissue biocompatible.
The shape of the flange 25 at its site of bonding to the tube may be splayed to allow greater strength. Thus, for example, as shown in FIG. 8 (for one non-limiting embodiment) the splaying 34, 35, 36 may advantageously allow the flange 25 to have a greater surface area that can be adhered to the tube 24.
As mentioned, the bonded second flange 25 can be made of any appropriately flexible material that retains its memory after deformation, such as, for example a silicone or a rubber, or indeed alternatively any suitable plastics material.
The exact shape of the second flange 25 can be chosen to suit the needs of each specific patient and so it need not necessarily be circular (as shown in FIG. 6A) in cross-section.
Thus, further non-limiting examples of the many different types that can be appropriately utilised are shown in FIGS. 9A-E. In particular, if the second flange 25 comprises a plurality of arms radiating from the central lumen 26, it is preferable that an odd number of arms are incorporated. This allows the arms to fold into a more compact arrangement as the flange 25 collapses, thus minimising the cross-sectional diameter of the device 21 as it is inserted into place or temporally withdrawn for cleaning. Additionally, the outer circumferential profile of the second flange 25 is preferably as uniformly smooth as possible, for example any arms should preferably have rounded extremities.
Importantly, the second flange 25 is pre-bonded at a predetermined set distance 22 from the internal end 27 of the glass tube 24, and so the clinician need not actually bond the second flange 25 to the tube 24 at any stage. Further, the glass tubes are also typically manufactured to predetermined lengths, so that, the length required to match each patient's anatomy can be chosen by the surgeon before the corrective procedure is commenced.
As noted above, many of the previously known devices appear to have been designed for insertion solely as a temporary measure after surgery and, as such, they are used simply to keep an artificially created passageway open for long enough for the patient's surrounding tissues to heal. Often known as "stents", these devices are removed once the appropriate number of weeks or months, after the surgery, have elapsed. In addition, almost all are usually inserted through at least a remaining part of the patient's own lacrimal apparatus that has retained some workable function.
By contrast, the improvements provided by the device 21 of the present invention allow it to be inserted, if necessary, as a relatively permanent system, often as an independent bypass of a patient's natural tear-duct system. The chosen parameters of the device 21 and particularly those of its second flange 25, greatly enhance its ability to efficiently provide this permanent type of treatment, by avoiding counter-productive complications (such as inflammation of the nearby tissues, and so forth) that, as mentioned above, might otherwise arise.
In use, as also indicated above, the present device 21 is particularly suited to correction of canalicular obstructions. Once the clinician has surgically created the appropriate bypass tissue passage into the nasal meatus 7, the device 21 can easily be placed into the correct in situ position (as shown in FIG. 6C). By making use of the slight elasticity of the intervening tissue, this can be achieved by inserting it inwardly into the passage (see FIG. 6B) until the leading edge 27 of the tube is sufficiently inside the nasal meatus 7. This allows the internal second flange 25 to have already flexibly opened out due to its inherent resilience. The device 21 can then be withdrawn slightly until the opened second flange 25 abuts the nasal mucosa surrounding the internal orifice of the bypass passage. The positioning of the internal second flange 25, and thus the in situ placement of the device 21 as a whole, can therefore be accurately controlled by the clinician.
The bonding of the second flange 25 to the tube 24 at a predetermined distance from the internal end 27 of the tube, ensures that a section 22 of the tube is proud of the second flange 25. Being proud, its obstruction (for example by the formation of scar tissue from the nasal mucosa) is much less likely when it is in situ, so helping to promote a more continuous drainage of the excess lacrimal fluid.
Devices according to the present invention may, of course, differ in their absolute dimensions from case to case, with these being specifically chosen so as to maximise the above-described advantages for each individual patient.
Purely as a way of illustrating this specificity in a non-limiting manner, in one embodiment of the present invention, the outer diameter of the first, rigid flange 28 might be chosen to be between about 3 to 4 mm, whilst that of the tube 24 would then suitably be about 2-2.5 mm. In such a case, the diameter of the second flange 25 would typically be of the order of 7.5 mm or less, and preferably about 5 mm. Its thickness 29 would consequently be of the order of 1 mm or less, and the tube's proud section 22 would also generally have a chosen length of about 1 mm.
The dimensions of any recesses 31 as mentioned above—for example see FIG. 7—can also be varied to accommodate the associated dimensions chosen for the second flange 25. Alternatively, portion of the tube 24 adjacent to the edges of the flange 25 can be raised slightly to provide support.
In conclusion, the advantages of the improved device according to the present invention, as compared to known devices, include the following.
It is simpler to insert, especially compared to devices having an enlarged flange as their leading edge. The large internal flange provides the much greater stability in situ that is required for a permanent device. Moreover, because its leading edge also provides in situ a set length of tube that is proud inside the nasal meatus, obstruction of the internal orifice of its lumen is much less likely.
It can also be readily removed on a temporary basis to allow its regular cleaning and, following its reinsertion, any risk of it falling out thereafter is minimised.
In order to remain securely in situ, the device does not depend upon gravity, by having the relatively large weight flanges that are used in some known devices.
The device also does not rely upon its tube having to be cut to size or glued during its insertion, or its flanges being cut off to allow its withdrawal.
Although preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims.


A radiation-curable composition for an ink base, ink composition, outer primary composition, buffering material or matrix material for fiber optics includes, in the uncured state, a secondary amino or tertiary amino silicone-containing additive.

1. Field of the Invention
The present invention relates generally to optical fiber coating compositions, and, more particularly, to fiber optic coating compositions that include a secondary or tertiary amino silicone-containing release agent, and to optical fibers coated with such compositions.
2. Description of Related Art
Optical glass fibers are frequently coated with two or more superposed radiation-curable coatings which together form a primary coating immediately after the glass fiber is produced by drawing in a furnace. The coating which directly contacts the optical glass fiber is called the xe2x80x9cinner primary coatingxe2x80x9d and an overlaying coating is called the xe2x80x9couter primary coating.xe2x80x9d In older references, the inner primary coating was often called simply the xe2x80x9cprimary coatingxe2x80x9d and the outer primary coating was called a xe2x80x9csecondary coating,xe2x80x9d but for reasons of a clarity, that terminology has been abandoned by the industry in recent years.
Inner primary coatings are softer than outer primary coatings.
Single-layered coatings (xe2x80x9csingle coatingsxe2x80x9d) can also be used to coat optical fibers. Single coatings generally have properties (e.g., hardness) which are intermediate to the properties of the softer inner primary and harder outer primary coatings.
The relatively soft inner primary coating provides resistance to microbending which results in attenuation of the signal transmission capability of the coated optical fiber and is, therefore, undesirable. The harder outer primary coating provides resistance to handling forces such as those encountered when the coated fiber is ribboned and/or cabled.
Optical fiber coating compositions, whether they are inner primary coatings, outer primary coatings, or single coatings, generally comprise, before cure, a polyethylenically-unsaturated monomer or oligomer dissolved or dispersed in a liquid ethylenically-unsaturated medium and a photoinitiator. The coating composition is typically applied to the optical fiber in liquid form and then exposed to actinic radiation to effect cure.
For the purpose of multi-channel transmission, optical fiber assemblies containing a plurality of coated optical fibers have been used. Examples of optical fiber assemblies include ribbon assemblies and cables. A typical ribbon assembly is made by bonding together a plurality of parallel oriented, individually coated optical fibers with a matrix material. The matrix material has the function of holding the individual optical fibers in alignment and protecting the fibers during handling and installation. Often, the fibers are arranged in xe2x80x9ctape-likexe2x80x9d ribbon structures, having a generally flat, strand-like structure containing generally from about 2 to 24 fibers. Depending upon the application, a plurality of ribbon assemblies can be combined into a cable which has from several up to about one thousand individually coated optical fibers. An example of a ribbon assembly is described in published European patent application No. 194891. A plurality of ribbon assemblies may be combined together in a cable, as disclosed, for example, in U.S. Pat. No. 4,906,067.
The term xe2x80x9cribbon assemblyxe2x80x9d includes not only the tape-like ribbon assembly described above, but optical fiber bundles as well. Optical fiber bundles can be, for example, a substantially circular array having at least one central fiber surrounded by a plurality of other optical fibers. Alternatively, the bundle may have other cross-sectional shapes such as square, trapezoid, and the like.
Coated optical fibers (or waveguides) whether glass, or, as has come into use more recently, plastic, for use in optical fiber assemblies are usually colored to facilitate identification of the individual coated optical fibers. Typically, optical fibers are coated with an outer colored layer, called an ink coating, or alternatively a colorant is added to the outer primary coating to impart the desired color.
Typically, the matrix material of a fiber optic ribbon assembly or cable is separated from the individual coated fibers in order to facilitate splicing two cables, or the connection of a fiber to an input or output. It is highly desirable that the matrix material can be removed from the coated fiber with little or no effect on the outer primary coating or colored ink coating of the fiber. Good removability of the matrix material not only preserves the readily visual identification of the color coded fiber, it also avoids harming the waveguide during the removal process.
Heretofore, certain types of silicone-containing compounds have been suggested for inclusion in the coloring layer and/or matrix materials to enhance the removability of the matrix material of the ribbon from color coated optical fiber. For example, U.S. Pat. No. 4,828,349 describes a multi-core optical fiber unit in which each optical fiber element is coated with a peel layer and bound into a ribbon or cable with a covering layer. The peel layer of each optical fiber is comprised of an ultraviolate curing or thermosetting fluorocarbon resin or an ultraviolet curing or thermosetting silicone resin.
U.S. Pat. No. 5,621,838 discloses a multi-fiber coated optical fiber unit in which each of the coated optical fibers has a coloring layer as the outermost layer and is coated with a bundling or matrix layer. The coloring n layers on the coated fibers and the matrix layer both contain a releasing agent consisting of a silicon resin or oil or a fluororesin or fluoro-oil as known in the art at the time the application for the patent was filed.
Japan laid-opened patent H1-152405 discloses an optical fiber taped core wire in which a plurality of optical core wires arranged in a plane are coated into a single unit. Each of the optical fiber core wires is coated with an ultraviolet cured resin and has a colored layer as its outermost layer. The colored layer includes an organic polysiloxane compound to improve the removability of the matrix coating. The organic polysiloxane compound includes at least one functional group, including an amino group.
Ink compositions which include silicone-based release agents have been used in the art, but are not entirely satisfactory. Silicone release agents, particularly those that are not reactive under the UV cure conditions, have been found to migrate in the ribbon assembly over time. Migration alters the release characteristics of the matrix materials from the outermost coating on the fiber optic, i.e., the outer primary coating or the ink coating, which is undesirable.
Silicone release agents are also known to impair the stability of the pigment dispersion in the ink composition leading to pigment flocculation, particularly when the silicone release agent is added to the finished ink composition. Silicone release agents can also reduce the efficiency of manufacturing optical fiber ribbon by slowing line speed and reducing cure rate of the ink composition.
Despite the efforts of the prior art to provide optical fiber coating compositions and ink compositions in which, when a plurality of optical fibers are formed into a ribbon assembly, the matrix material of the ribbon assembly is easily removed from the ink composition, there remains a need for new release agents for ink compositions which allow for improved release of the matrix material, improve the stability of the pigment dispersion in the ink composition even when the release agent is added to the finished ink composition, and allow for improved efficiency and speed of manufacture of optical fiber ribbon.
The present invention is predicated on the discovery that secondary and tertiary amino silicone-containing compounds can be added to radiation curable compositions typically used as coatings in the optical fiber field, including, ink base compositions, inks, outer primary coatings, single coatings, buffering material and matrix material, to effect the release of adjacent coatings from one another when needed, such as, for example, in field applications. The secondary and tertiary amino silicone-containing compounds are compatible with ink bases and with finished ink compositions, and they show excellent pigment dispersion stability in both ink bases and ink compositions, even when the silicone-containing additive is post added to finished inks. Secondary and tertiary amino additives are desirably not fugitive, and they do not tend to migrate significantly in ribbon structures, thereby avoiding changes in release characteristics over time.
In accordance with the present invention, fiber optic coating compositions which include a secondary amino or tertiary amino silicone-containing release agent are provided. It will also be appreciated by those skilled in the art that both a secondary and a tertiary amino silicone-containing release agent can be included in fiber optic coating compositions, as desired. Use of the silicone-containing release agents in accordance with the invention facilitates removability or separability of two adjacent layers on a coated optical fiber.
The release agents in accordance with the present invention can be used in an ink base composition, i.e., an uncolored composition, later colored for example with a pigment, dye or the like. Similarly, the release agents of the present invention can be used in an ink composition, that is, a composition which includes the desired coloring agent. Inclusion of the secondary or tertiary amino silicone-containing release agent in the colored coating on the optical fiber in accordance with the invention assists in the removability or separability of the ribbon matrix materials from the colored coating. Thus, when optical fibers coated with an ink composition of the present invention are ribbonized, and removal of the ribbon material from the fibers is desired to facilitate connectorizing operations, for example, the unwanted matrix material can be stripped from the colored coating while, at the same time, the color coating on each fiber optic is retained. It will be appreciated that the release agents described herein can be used in the outer primary coating, in buffering materials typically used as a coating on single optical fibers, in single coatings and in matrix materials.
Any of a wide variety of secondary and tertiary amino silicone-containing release additives can be used in the coating compositions of the present invention. Secondary and tertiary amino derivatives of di-substituted disiloxanes and polydi-substituted siloxanes are the desired silicone-containing additives in accordance with the invention. Such silicone-containing release additives that have been found useful are compounds that include the structure:
wherein each of R1, R2, R3 and R4 can be the same or different and each is an aliphatic or an aromatic hydrocarbon. Illustrative of the aliphatic hydrocarbons that can be any of R1 through R4 are alkyl groups of from 1 to about 20 carbon atoms, preferably from 1 to about 8 carbon atoms and most preferably from 1 to about 4 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl or the like. Illustrative of the aromatic groups that can be any of R1 through R4 are phenyl and phenyl derivatives. An example of a compound having the structure (I) above wherein R1, R2, R3 and R4 are alkyl and aromatic is diphenyl dimethylsiloxane, e.g., Mirasil DPDM available from Rhone-Poulenc.
Dimethyl disiloxane silicone-containing additives are preferred. An example of a dimethyl disiloxane silicone-containing additive that is useful in the fiber optic compositions of the present invention are secondary and tertiary amino derivatives of epoxycyclohexylethyl dimethyl disiloxanes.
Illustrative of secondary and tertiary amino polydi-substituted siloxanes that are useful in the fiber optic compositions of the present invention are xcex1,xcfx89-aminoorganofunctional polydi-substituted siloxanes of the Formula II:
wherein R1, R2, R3 and R4 are as defined above, and n is an integer of from about 5 to about 50, and preferably of from about 10 to about 35.
The substituents R5 and R6 are not narrowly critical to the invention. Each of R5 and R6 can be the same or different. R5 and R6 typically form a part of the silicone-containing additive to increase the molecular weight of the compound to a molecular weight sufficiently high to achieve the desired release properties, and to render the silicone-containing compound soluble in the UV-curable composition. Preferably, each of R5 and R6 is an alkoxy or ring opened epoxy, such as ethoxy, propoxy, butoxy and repeat units thereof. Such materials are preferred as they enhance the compatibility of the silicone-containing compound with the components typically utilized in UV-curable compositions.
The substituents R7 and R8 are also not critical to the invention, and can be the same or different. Generally, R7 and R8 can each independently be an aliphatic or an aromatic hydrocarbon. Preferably, each of R7 and R8 is a sterically hindered group, such as a branched alkyl group having at least 3 carbon atoms or an alicyclic or heterocyclic hydrocarbon. The alkyl, alicyclic and aromatic hydrocarbons can also be substituted, such as, for example, with alkyl, alkenyl, hydroxyl, carboxyl, or carbonyl groups or the like. Examples of branched alkyl groups include isopropyl, t-butyl, isopentyl or the like. Examples of alicyclic hydrocarbons and aromatic hydrocarbons, include, by way of illustration, cyclopentyl, cyclohexyl, phenyl, toluyl, or the like. Examples of heterocyclic hydrocarbons include furan, thiophene, oxazole, thiazole, pyridine, pyrimidine, quinoline, or the like. The hindered group can also be long chain fatty acids of, for example, twelve or more carbon atoms.
The preferred xcex1,xcfx89-aminoorganofunctional polydi-substituted siloxanes are xcex1,xcfx89-aminoorganofunctional polydimethyl siloxanes having the Formula II described above. The functional groups on such compounds are secondary amino groups and the compounds have a functionality of two. One such compound (Additive A)is further characterized as having about 10 repeating units, i.e., n≅10, a nitrogen content of about 3%, an active hydrogen-equivalent weight of amine of about 460, a viscosity at 25xc2x0 C. of about 10 mPas, and a specific gravity at 25xc2x0 C. of about 0.93 g/cm3. Another such compound (Additive B) is further characterized as having about 30 repeating units, i.e., n≅30, a nitrogen content of about 1.2, an active hydrogen-equivalent weight of amine of about 1,160, a viscosity at 25xc2x0 C. of about 35 mPas and a specific gravity at 25xc2x0 C. of about 0.96 g/cm3.
The use of secondary amino silicone-containing release agents is preferred. Secondary amino silicone-containing release agents are not prone to be fugitive and tend not to migrate in the composition over time, yet they still provide very desirable release characteristics.
The amount of secondary or tertiary amino silicone-containing agent included in the composition is not narrowly critical. The silicone-containing additive need be added only in an amount sufficient to achieve the desired release, peel and separability characteristics, and the exact amount added to any particular fiber optic composition can be determined readily by one skilled in the art. For example, the silicone-containing additive can be included in an amount of from about 0.1 to about 10 wt. % of the composition, preferably from about 0.5 wt. % to about 5 wt. % of the composition, and most preferably from about 1 wt. % to about 4 wt. % of the composition.
Ink compositions in accordance with the present invention tend to minimize or even avoid fugitivity of the silicone-containing additive, unlike ink compositions with non-reactive silicone-containing additives, and they tend to minimize or avoid migration of the silicone-containing additive in the ribbon assemblies made with ink coated optical fiber. The ink compositions of the present invention can be applied to optical fiber at faster line speeds than compositions with silicone-containing additives previously known. Accordingly, throughput rate is enhanced.
Advantageously, the ink compositions of the present invention exhibit excellent release from matrix materials in ribbon assemblies, while maintaining good adhesion to the outer primary coating. They also exhibit excellent MEK resistance and breakout. Thus, ribbon assemblies made with fiber colored with the ink composition of the present invention are especially well-suited to field applications where the matrix material is removed for connectorizing operations, leaving the colored fiber exposed to facilitate ready identification of the colored fiber for connection.
The coating composition of the present invention is applicable to all radiation-curable, optical fiber coating compositions, whether used to coat glass or plastic waveguides.
Examples of suitable radiation-curable compositions which may be used variously include those which are disclosed, for example, in U.S. Pat. Nos. 4,624,994, 4,682,851, 4,782,129, 4,794,133, 4,806,574, 4,849,462, 5,219,896 and 5,336,563, all of which are incorporated herein by reference. These compositions can be reformulated and utilized as the radiation-curable carrier system in the ink base and ink composition according to the present invention.
Inner primary, outer primary, ink base and ink radiation-curable compositions contain one or more radiation-curable oligomers or monomers having at least one functional group capable of polymerization when exposed to actinic radiation. Suitable radiation-curable oligomers or monomers are now well known and within the skill of the art.
Commonly, the radiation-curable functionality used is ethylenic unsaturation, which can be polymerized through radical polymerization or cationic polymerization. Specific examples of suitable ethylenic unsaturation are groups containing acrylate, methacrylate, styrene, vinylether, vinyl ester, N-substituted acrylamide, N-vinyl amide, maleate esters, and fumarate esters.
Preferably, the ethylenic unsaturation is provided by a group containing acrylate, methacrylate, N-vinyl or styrene functionality.
In one embodiment of the invention, the present invention provides a radiation curable fiber optic ink base composition comprising, in the uncured state, at least one monomer or oligomer having a radiation-curable functional group, a photoinitiator for the monomer or oligomer and a silicone-containing additive comprising the reaction product of a secondary amino-functional poly(di-substituted siloxane) and an ethylenically unsaturated compound.
The photoinitiator described in the fiber optic ink base composition is present in an amount sufficient to effect radiation cure of the monomer or oligomer. The siloxane is substituted with at least one aliphatic hydrocarbon, at least one aromatic hydrocarbon or combinations of aliphatic and aromatic hydrocarbons. It is contemplated that the ethylenically unsaturated compound includes only one double bond allowing the reaction product of the secondary amino-functional poly(di-substituted siloxane) and the ethylenically unsaturated compound to be substantially free of ethylenic unsaturation. These ethylenically unsaturated compounds are, for example, an acrylate or methacrylate.
Another type of functionality generally used is provided by, for example, epoxy groups, or thiol-ene or amine-ene systems. Epoxy groups can be polymerized through cationic polymerization, whereas the thiol-ene and amine-ene systems are usually polymerized through radical polymerization. The epoxy groups can be, for example, homopolymerized. In the thiol-ene and amine-ene systems, for example, polymerization can occur between a group containing allylic unsaturation and a group containing a tertiary amine or thiol.
For the ink base and ink compositions, preferably at least about 80 mole %, and more preferably, at least about 90 mole % of the radiation-curable functional groups present in the oligomer are acrylate, methacrylate and N-vinyl.
A mixture of mono-, di-, tri-, tetra-, and higher functionalized oligomers can be used to achieve the desired balance of properties, wherein the functionalization refers to the number of radiation-curable functional groups present in the oligomer.
The oligomers usually comprise a carbon-containing backbone structure to which the radiation-curable functional group(s) are bound. For example, the oligomer can be represented by the formula:
Rxe2x80x94Xxe2x80x94R; or
xe2x80x83Rxe2x80x94Lxe2x80x94Xxe2x80x94Lxe2x80x94R
where R is a radiation-curable functional group,
X is a carbon-containing polymeric backbone, an aromatic group containing moiety, or a combination thereof, and
L is a linking group.
The size of the carbon-containing backbone is preferably selected to provide the desired molecular weight and the selection of the backbone can take into account the limiting group L, if a linking group is included in the oligomer. The number average molecular weight of the oligomer is desirably of from about 200 to about 30,000, preferably of from about 500 to about 7,000, and most preferably of from about 1,000 to about 5,000.
Illustrative of suitable carbon-containing polymeric backbones include a polymeric backbone of a polyether, a polyolefin, a polyester, a polyamide, a polycarbonate, an alkyd or mixtures thereof.
Further, by way of example, the carbon-containing backbone of the oligomer can comprise aromatic groups and ring-opened epoxy groups or alkoxy groups.
The aromatic groups can be derived, for example, from bisphenol units, such as bisphenol A. Suitable oligomers are well known to those skilled in the art. A preferred oligomer is a diglycidyl ether derivative of bisphenol A to which acrylate functional groups have been bound. A commercially available example of such an oligomer is CN-120 (Sartomer), which has a molecular weight of about 500, and when cured has a Tg of about 65xc2x0 C.
Examples of suitable linking groups include alkoxy or ring opened epoxy such as ethoxy, propoxy, butoxy, and repeat units thereof. L can also be a urethane or urea linking group.
Another example of a preferred oligomer is a trifunctional polyether or polyester having a molecular weight of about 500 to about 5000. A preferred example of a trifunctional oligomer is the commercially available polyurethane triacrylate, xe2x80x9cOligomer B,xe2x80x9d which has a molecular weight of about 2000, and when cured a Tg of about 42xc2x0 C.
The tertiary amino silicone-containing release agent can be an oligomer, which, in a preferred embodiment, makes use of intermediate linking groups. This oligomeric release agent is represented by the following generic structure:
Rxe2x80x94L1xe2x80x94Axe2x80x94L2xe2x80x94R
wherein A represents a silicone-containing moiety,
R represents an amino-containing group which may, but need not contain, a radiation-curable moiety, and
L1 and L2 represent linking groups.
L1 and L2 can be independently any group capable of providing a covalent link between the xe2x80x9cRxe2x80x9d moiety and the xe2x80x9cAxe2x80x9d moiety. Based on the disclosure provided herein, one skilled in the art will easily be able to understand what linking groups are suitable for the particular xe2x80x9cAxe2x80x9d and xe2x80x9cRxe2x80x9d groups selected.
In particular, urethane groups are preferred. Urethane linking groups are formed by, for example, (i) linking a hydroxyl end-capped oligomer with a low molecular weight diisocyanate compound at both oligomer ends without extensive coupling of the oligomer, (ii) linking the isocyanate end-capped oligomer with a low molecular weight amine.
In a preferred embodiment of the present invention the secondary or tertiary amino silicone-containing release agent is prepared as a composite oligomer with use of the following ingredients: silicone-containing compound having two hydroxyl end groups (A), isophorone diisocyanate (L1, L2), and hydroxyl-containing radiation-curable moiety which is then capped with an amine. Isophorone diisocyanate (IPDI) serves to end-cap both ends of the silicone diol oligomer and provide a linking site with the radiation-curable moiety capped with the amine.
Examples of diisocyanates that can be used in the practice of the present invention in the preparation of the tertiary amino silicone-containing release agent include:
toluene diisocyanate (TDI);
diphenylmethane diisocyanate (MDI);
phenylene diisocyanate (PDI);
naphthalene diisocyanate (NDI);
tetramethylxylene diisocyanate (TMXDI);
meta-xylene diisocyanate (MXDI);
bis 4,4xe2x80x2-(isocyanatocyclohexyl)methane (DES W)(HMDI);
isophorone diisocyanate (IPDI);
hexamethylenediisocyanate (HDI);
trimethylhexamethylene diisocyanate (TMDI);
trans-cyclohexane diisocyanate (Elate 166);
1,3-bis(isocyanatomethyl)cyclohexane (1,3 BIC);
dimer acid diisocyanate (DDI-1410);
norbornene diisocyanate (NBDI);
dimethyl meta-isopropenyl benzyl isocyanate (meta-TMI);
trifunctional biuret adduct of HDI;
isocyanurate trimer of HDI; and
isocyanurate trimer of IPDI and the like.
By way of illustration, and not in limitation of the present invention, a silicone urethane can be prepared by reacting a silicone-containing compound with an isocyanate group to form a urethane-containing silicone precursor. The precursor can then be reacted with a secondary or tertiary amino-containing compound to form the secondary or tertiary amino silicone-containing urethane. For example, an hydroxy functional alkoxy-polydimethylsiloxane can be, reacted with a diisocyanate to form a silicone-containing urethane precursor containing an isocyanato group. The silicone-containing urethane precursor can then be reacted with a compound which includes a tertiary amine to form an amino silicone-containing compound. Preferably, the amino silicone containing compound is thus reactive with the isocyanato group of the precursor. This reaction may take place through any reactive substituent in the compound.
Preferably, the secondary or tertiary amino compound has a reactive moiety such as a hydroxy moiety that can react with the urethane precursor to form the silicone urethane. Examples of secondary and tertiary amine compounds that can be used in the practice of the invention include dialkyl alcohol amines such as dimethylethanol amine, dimethyl propanol amine, diethanol amine or the like, cyclic amines, including hydroxyethyl morpholine, 1-ethyl-3-hydroxy piperidine, or the like.
Inner primary, outer primary, ink base and ink radiation-curable compositions may also contain a reactive diluent which is used to adjust t e viscosity. The reactive diluent can be a low viscosity monomer having at 1east one functional group capable of polymerization when exposed to actinic radiation. Usually, the viscosity of the low viscosity diluent monomer is from about 50 to about 500 centipoise at 25xc2x0 C. Examples of suitable viscositie for optical glass fiber coating compositions range from about 500 to about 50,000 centipoise at 25xc2x0 C. Preferred amounts of radiation-curable diluent monomer include from about 5 to about 70% by weight, more preferably, from about 10 to about 60% by weight, based on the total weight of the composition.
The functional group in the reactive diluent may be of the same nature as Gthat used in the radiation-curable monomer or oligomer. Preferably, the functional group present in the reactive diluent is capable of copolymerizing with the radiation-curable functional group present on the radiation-curable monomer or oligomer. More preferably, the radiation-curable functional group forms free radicals during curing which can react with the free radicals generated on the surface of the surface treated optical fiber.
For example, the reactive diluent can be a monomer or mixture of monomers having an acrylate or vinyl ether functionality and a C4-C20 alkyl or polyether moiety. Particular examples of such reactive diluents include:
hexylacrylate,
2-ethylhexylacrylate,
isobornylacrylate,
decyl-acrylate,
laurylacrylate,
stearylacrylate,
2-ethoxyethoxy-ethylacrylate,
laurylvinylether,
2-ethylhexylvinyl ether,
N-vinyl formamide,
isodecyl acrylate,
isooctyl acrylate,
vinyl-caprolactam,
N-vinylpyrrolidone,
and the like.
Another type of reactive diluent that can be used is a compound having an aromatic group. Particular examples of reactive diluents having an aromatic group include:
ethyleneglycolphenylether acrylate, polyethyleneglycolphenylether acrylate,
polypropyleneglycolphenylether acrylate, and
alkyl-substituted phenyl derivatives of the above monomers, such as polyethyleneglycolnonylphenylether acrylate.
The reactive diluent can also comprise a diluent having two or more functional groups capable of polymerization. Particular examples of such monomers include:
C2-C18 hydrocarbondioldiacrylates,
C4-C18 hydrocarbondivinylethers,
C3-C18 hydrocarbon triacrylates, and the polyether analogues thereof, and the like, such as
1,6-hexanedioldiacrylate,
trimethylolpropanetriacrylate,
hexanedioldivinylether,
triethyleneglycoldiacrylate,
pentaerythritoltriacrylate,
ethoxylated bisphenol-A diacrylate, and
tripropyleneglycol diacrylate.
If the radiation-curable functional group of the radiation-curable monomer or oligomer is an epoxy group, for example, one or more of the following compounds can be used as the reactive diluent:
epoxy-cyclohexane,
phenylepoxyethane,
1,2-epoxy-4-vinylcyclohexane,
glycidylacrylate,
1,2-epoxy-4-epoxyethyl-cyclohexane,
diglycidylether of polyethylene-glycol,
diglycidylether of bisphenol-A,
and the like.
If the radiation-curable functional group of the radiation-curable monomer or oligomer has an amine-ene or thiol-ene system, examples o reactive diluents having allylic unsaturation that can be used include:
diallylphthalate,
triallyltri-mellitate,
triallylcyanurate,
triallylisocyanurate, and
diallylisophthalate.
For amine-ene systems, amine functional diluents that can be used include, for example:
the adduct of trimethylolpropane,
isophoronediisocyanate and
di(m)ethylethanolamine,
the adduct of hexanediol, isophoronediisocyanate
and dipropylethanolamine, and
the adduct of trimethylol propane, trimethylhexamethylenediisocyanate and di(m)ethylethanolamine.
The radiation-curable ink composition can contain free-radical generating photoinitiators. Examples of suitable free radical-type photoinitiators include, but are not limited to, the following:
isobutyl benzoin ether;
2,4,6-trimethylbenzoyl, diphenylphosphine-oxide;
1-hydroxycyclohexylphenyl ketone;
2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one;
2,2-dimethoxy-2-phenylacetophenone;
perfluorinated diphenyl titanocene;
2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone;
2-hydroxy-2-methyl-1-phenyl propan-1-one;
4-(2-hydroxyethoxy)phenyl-2-hydroxy-2-propyl ketone dimethoxyphenylacetophenone;
1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one;
1-(4-dodecyl-phenyl)-2-hydroxy-2-methylpropan-1-one;
4-(2-hydroxyethoxy)phenyl-2(2-hydroxy-2-propyl)-ketone;
diethoxyphenyl acetophenone;
a mixture of (2,6-dimethoxy benzoyl)-2,4,4 trimethylpentylphosphineoxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one;
benzophenone;
1-propanone, 2-methyl-1-(4-(methylthio)phenyl)2-(4-morpholinyl); and
mixtures of these.
Other additives which can be used in the coating composition include, but are not limited to, catalysts, lubricants, wetting agents, antioxidants and stabilizers. The selection and use of such additives is within the skill of the art.
Single coatings can also be used. Exemplary single coatings are disclosed in, for example, U.S. Pat. No. 4,932,750, which is hereby is incorporated by reference. Single coatings, like inner primary coatings, generally comprise oligomer, reactive diluent, and optional photoinitiator and additives. Conventional outer primary coatings can be used in the practice of this invention as disclosed in, for example, U.S. Pat. No. 4,472,019, which is hereby incorporated by reference.
The ink base and ink compositions of the present invention can include an adhesion promoter, such as disclosed, for example, in U.S. Pat. No. 5,812,725.
The colorant for the ink composition of the present invention can be any pigment or dye that is suitable for making radiation-curable ink compositions. The use of the term xe2x80x9cpigmentxe2x80x9d refers to both inorganic and organic pigments. Preferably, pigment is utilized in the form of a pigment dispersion in order to simplify dispersion of the pigment within the ink coating composition. The pigment dispersion usually comprises one or more pigments dispersed in a low viscosity liquid, such as a reactive diluent, in such an amount that the pigment dispersion is easily pourable under ambient temperatures. For example, amounts of about 1 to about 80% by weight pigment dispersed in a reactive diluent have been found to be suitable. Pigment dispersions are well known and therefore one skilled in the art will be able to utilize well known pigment dispersions to formulate improved ink compositions according to the present invention based on the disclosure provided herein.
Ribbon assemblies utilizing 12 or less coated optical glass fibers require only 12 colors to adequately distinguish each of the coated optical fibers from one another. However, in larger ribbon assemblies, more than 12 colors may be utilized to adequately distinguish the coated optical glass fibers from one another. Examples of twelve colors normally used for making ribbon assemblies include: black, white, yellow, blue, red, green, orange, brown, pink, aqua, violet and gray.
A specific example of a suitable black pigment includes carbon black.
A specific example of a suitable white pigment includes titanium dioxide.
Specific examples of suitable yellow pigments include diarylide yellow and diazo based pigments.
Specific examples of suitable blue pigments include phthalocyanine blue, basic dye pigments, and phthalocyanines.
Specific examples of suitable red pigments include anthraquinone (red), naptholy red, monoazo based pigments, quinacridone pigments, and perylenes.
Specific examples of suitable green pigments include phthalocyanine green and nitroso based pigments.
Specific examples of suitable orange pigments include monoazo and diazo based pigments, quinacridone pigments, anthraquinones and perylenes.
Specific examples of suitable violet pigments include quinacridone violet, basic dye pigments and carbazole dioxazine based pigments.
Suitable aqua, brown, gray, and pink pigments can easily be formulated by combining other colors. One skilled in the art is able to from any color as desired by combining different coloring agents.
The pigment can be present in the ink composition in an amount that provides coloration that is visible without magnification to facilitate identification of the individual colored optical glass fiber. The amount of the pigment should not be so great as to significantly reduce the cure speed of the ink composition or result in other undesirable affects. Examples of suitable amounts of pigment have been found to be from about 1 to about 20 wt. %, preferably about 1 to about 15 wt. %, more preferably about 1 to about 10 wt. %, based on the total weight of the ink composition.
Preferably, the ink composition contains at least one photoinitiator in an amount of from about 1 to about 20% by weight, more preferably from about 1 to about 10% by weight, based on the total weight of the ink composition.
The ink coating composition can be applied to the coated optical glass and cured using any suitable method. An example of a suitable method is disclosed in U.S. Pat. No. 4,629,285, the complete disclosure of which is incorporated herein by reference. The ink composition can also be applied in a manner similar to the application of the outer primary coating on an optical glass fiber drawing and coating tower.
Ink coatings are usually about 3 to about 10 microns thick and are usually concentric to prevent attenuation of the signal transmission. However, if desired, the ink coating can be applied in any form suitable to provide visible color identification of the individual coated optical glass fibers. Examples of suitable coatings include dashes, dots, lines, and rings. Preferably, the ink coating is substantially concentric. The ink coating compositions according to the present invention are capable of providing substantially concentric ink coatings, as well as discontinuous coatings such as dashes, dots, lines, and rings.
Ribbon assemblies are now well known in the art and the disclosure provided herein will enable one skilled in the art to prepare a novel ribbon assembly containing at least one of the improved coated optical fibers of the present invention for the desired application. The novel ribbon assembly made according to this invention can be used in telecommunication systems. Such telecommunication systems typically include ribbon assemblies containing optical fibers, transmitters, receivers, and switches. The ribbon assembly containing the coated optical fiber of the present invention is the fundamental connecting unit of telecommunication systems. The ribbon assembly can be buried underground or can be laid under water for long distance connections, such as between cities. The ribbon assembly can also be used to connect directly to residential homes.
The novel ribbon assembly made according to this invention can also be used in cable television systems. Such cable television systems typically include ribbon assemblies containing optical fibers, transmitters, receivers and switches. The ribbon assembly containing the coated optical fibers of the present invention is the fundamental connecting unit of such cable television systems, and, like telecommunication systems, can be buried under ground or laid under water for long distance connections, or can be used to connect directly to residential homes.

Optical fiber coating compositions containing secondary or tertiary amino silicone-containing additive


A process for the purification of 2-methoxy-5-trifluoro-methoxy benzaldehyde oil in which the oil is converted to amine by reaction of a nitroaniline with the oil; the imine is isolated as a solid; and the solid imine is converted back to the 2-methoxy-5-trifluoromethoxy benzaldehyde oil. The nitroaniline is selected from the group consisting of 3-nitroaniline, 3-methyl-2-nitroaniline, 4-methyl-2-nitroaniline, 2 methyl-3-nitroaniline and 4-methyl-3-nitroaniline.

This invention relates to a new and useful process for the purification of 2-methoxy-5-trifluoro-methoxy benzaldehyde by conversion to a series of nitroanilines. In particular, it is concerned with a novel two step process for purifying the oil, 2-methoxy-5-trifluoro-methoxybenzaldehyde, wherein the oil is first converted to a nitroaniline. The nitroaniline is isolated as a solid imine and then simply converted back to the oil, 2-methoxy-5-trifluoro-methoxy-benzaldehyde. The result is a drastic reduction in the impurities seen in the commercial source which is the usual starting ingredient for the preparation of substance P receptor antagonists.
In accordance with the prior art U.S. Pat. No. 5,294,744 issued Mar. 15, 1994, there has already been described in a two-step reaction a process for preparing 5-substituted-2-methoxybenzaldehyde compounds wherein the substituent group is either isopropyl or trifluoromethoxy. The process involves (1) reacting a corresponding 4-substituted phenol compound with dimethyl carbonate in the presence of a tertiary-amine base to form the corresponding 4-substituted anisole compound. The second step (2) subjects the latter intermediate product obtained in the first step to aromatic C-formylation on the ring with hexamethylenetetramine in the presence of trifluoroacetic acid, followed by hydrolysis, to ultimately yield the desired aldehyde compound. The two aromatic aldehyde compounds so obtained, viz., 2-methoxy-5-trifluoromethoxybenzaldehyde and 2-methoxy-5-isopropylbenzaldehyde, are known to be useful as intermediates that specifically lead to (2S, 3S)-cis-3-(2-methoxy-5-trifluoromethoxylbenzyl)amino-2-phenylpiperidine and (2S, 3S)-cis-2-(diphenylmethyl)-N-[(2-methoxy-5-isopropylphenyl)-methyl]-1-azabicyclo[2.2.2]octane-3-amine, respectively. The latter final products, in turn, are both known to be useful in the field of medicinal chemistry as substance P receptor antagonists.
In accordance with the prior art, there has already been described certain compounds which are known to be of value as substance P receptor antagonists. Included among these are such nitrogen-containing heterocyclic ring compounds as (2S, 3S)-cis-3-(2-methoxy-5-trifluoromethoxylbenzyl)amino-2-phenylpiperidine, which is described and claimed by J. A. Lowe, III, et al., in U.S. Pat. No. 5,773,450, issued Jun. 30, 1998, and (2S, 3S)-cis-2-(diphenylmethyl)-N-[(2-methoxy-5-isopropylphenyl)-methyl]-1-azabicyclo[2.2.2]octane-3-amine, which is described and claimed by F. Ito, et al., in U.S. Pat. No. 5,807,867, issued Sep. 15, 1998. Both compounds are useful as non-steroidal anti-inflammatory (N.S.A.I.) agents, being of specific value in the treatment of arthritis, asthma and inflammatory bowel disease.
In the past, these particular compounds have been prepared by various synthetic means but essentially by a method which involves the reductive amination of the appropriate aldehyde compound, i.e., by reacting either the oily compound 2-methoxy-5-isopropylbenzaldehyde or 2-methoxy-5-trifluoromethoxybenzaldehyde, as the case may be, with the corresponding heterocyclic 3-amino compound in the presence of a source of hydrogen or else it can be made by first condensing the aforesaid 3-amino compound with the aldehyde and then reducing the resulting imine intermediate to ultimately give the key benzylamine side chain. The starting aromatic aldehyde component in this particular reaction scheme had always been prepared in two steps starting from the corresponding known and readily available 4-substituted phenol compound. This, in turn, initially involved (1) first methylating the phenol compound with methyl iodide in an acetone solvent medium in the presence of solid potassium carbonate, followed by (2) direct formylation of the resulting 4-substituted methylated phenol (i.e., 4-substituted anisole compound) with xcex1-dichloromethyl methyl ether in a methylene chloride solvent system in the presence of titanium tetrachloride as catalyst. However, this particular two-step method for the production of the aldehyde suffers from the drawback of being conducted in a non-homogenous reaction system in the first step, with all its attendant disadvantages, and in employing the somewhat hazardous titanium tetrachloride reagent as catalyst in the second step. In the latter connection, it should be noted that certain stringent safety requirements are normally called for when handling the latter agent, particularly when unit operations are conducted on a large scale. Additionally, the use of various hazardous waste disposal techniques are also required for the removal of the titanium tetrachloride byproducts that are usually formed in the aforesaid aromatic formylation reaction.
In the past, F. Merger, et al. in the U.S. Pat. No. 4,129,949 indicate that they have prepared various methyl phenyl ethers, including both 4-methylanisole and 4-methoxyanisole, from the corresponding phenol compounds, using dimethyl carbonate in the presence of a tertiaryamine base as catalyst without the presence of a solvent. Although the Merger, et al. patent also includes p-isopropylphenol in a long list of many other possible phenolic starting materials for the aforementioned reaction, there is no indication that 4-isopropylanisole was ever actually prepared in this particular manner. On the other hand, W. E. Smith in the Journal of Organic Chemistry, Vol. 37, No. 24, p. 3972 (1972) reports on its direct C-formylation of several aromatic compounds, including 2,6-dimethylanisole, via a method which involves the use of hexamethylenetetramine in trifluoroacetic acid in a modified Duff reaction, but there is no indication in the aforesaid paper by Smith that such a reaction could ever be successfully carried out using other non-acidic derivatives of anisole as substrate. In particular, there is no indication that the reaction of Smith could be applied to parasubstituted derivatives of anisole.
A process for the purification of 2-methoxy-5-trifluoro-methoxy benzaldehyde oil comprising converting the oil to an to amine by reacting of a nitroaniline with the oil; isolating the imine as a solid; and converting back the solid imine to the 2-methoxy-5-trifluoromethoxy benzaldehyde oil. The nitro-aniline is selected from the group consisting of 3-nitroaniline, 3-methyl-2-nitroaniline, 4-methyl-2-nitroaniline, 2-methyl-3-nitroaniline and 4-methyl-3-nitroaniline. The iminess are selected from the group consisting of
(2-Methoxy-5-trifluoromethoxybenzylidene)-(3-nitrophenyl)amine;
(2-Methoxy-5-trifluoromethoxybenzylidene)-(4-mehtyl-2-nitrophenyl)amine;
(2-Methoxy-5-trifluoromethoxybenzylidene)-(3-mehtyl-2-nitrophenyl)amine;
(2-Methoxy-5-trifluoromethoxybenzylidene)-(2-methyl-3-nitrophenyl)amine;
(2-Methoxy-5-trifluoromethoxybenzylidene)-(4-mehtyl-3-nitrophenyl)amine;
(2-Methoxy-5-trifluoromethoxybenzylidene)-(4-nitrophenyl)amine;
(2-Methoxy-5-trifluoromethoxybenzylidene)-(3,5-dinitrophenyl)amine;
(2-Methoxy-5-trifluoromethoxybenzylidene)-(1,6-dinitrophenyl)amine;
(2-Methoxy-5-trifluoromethoxybenzylidene)-(2,4-dinitrophenyl)amine;
(2-Methoxy-5-trifluoromethoxybenzylidene)-(5-methyl-2-nitrophenyl)amine; and
(2-Methoxy-5-trifluoromethoxybenzylidene)-(6-methyl-2-nitrophenyl)amine.
The temperature range in which to precipitate the imine is about 30 to about 40xc2x0 C. The solvent used to recrystallize the imine is selected from the group consisting of ethanol, methanol and ethanol/hexane. The solvent used to recrystallze the 2-methoxy-5-trifluoromethoxy benzaldehyde is a mixture of hexane and hydrochloric acid.
In accordance with the process of this invention, a purified solid from the oil, 2-methoxy-5-trifluoromethoxybenzaldehyde, was attempted by a protection reaction with its aldehyde functional group. Two ways were first investigated: either making the acetal or the imine. The acetal reactions were not successful. However, the second attempt using a nitroaniline compound gave a solid imine which was easily deprotected and gave a good yield. More importantly, the processes had highly-decreased the level of impurity of 2-methoxy-5-trifluoromethoxybenzaldehyde, now again in the oil form.
The idea behind the purification of the aldehyde was to make a solid from the oil and to filtered out the impurities. At first, the focus was on the possibility of making the acetal but that was without success. Next investigative reactions of imine formation were tried with some amines using nitroaniline analogues. This gave a solid very quickly and easily.
The imine formation implies equilibrium and most nitro compounds do not have good solubility in such solvent. But the high stability of the conjugated structure proposed by the imine drove the equilibrium to the formation of the imine. The difference of solubility between the original nitroaniline analogues and the imine helped to complete the reaction with a very good yield.
Having discerned that the main problem was to search for a good mixture of solvent that ensures a precipitation of the imine, it was possible to manage the solubility by controlling the temperature and the solvent composition. It was also possible to obtain a list of conditions to enhance imine formation. Adjusting the temperature gave better control of the reaction.
The best conditions were achieved with the 3-nitroaniline analogue. The solution was heated to 55xc2x0 C. where it became homogeneous and then, the solution was slowly cooled to 31-34xc2x0 C. where precipitation started. For 1 hour, the solution was stirred between 34-37xc2x0 C. to get a better crystallization. The solution was slowly cooled down to 0xc2x0 C., filtered and washed with cold hexane.
Because the solid imine is stabilized by its conjugated structure, it is possible to recrystallized it at high temperature without decomposing it. Analysis on the 3-nitroaniline imine complex showed that the recrystallization processes give only one isomer. By keeping the solid in solution, NMR shows its transformation to other isomers with time. This suggests that the imine is in equilibrium between its geometric isomers.
The deprotection reaction implies that there is a biphasic system in which the imine is stirred for a certain time. The acid aqueous layer stabilizes the amine and the benzaldehyde showed a great solubility in hexane. Depending on the nitroaniline analogue, it can take between 1 hour and 15 hours to form the imine.
It appears that the formation of the imine via the nitroaniline works best because of its easy reaction conditions and its defined recrystallization conditions. However, further investigation into the other amine analogues resulted in better conditions for most of the other amine analogues.
Accordingly to these results, the deprotection of benzaldehyde derivatives can be done by any nitroaniline analogues as long as solubility conditions are fixed.
All compounds show a important decrease of impurity. Moreover, compounds (2-Methoxy-5-trifluoromethoxybenzylidene)-(3-nitrophenyl)amine and 2-Methoxy-5-trifluoromethoxybenzylidene)-(4-methyl-2-nitrophenyl)amine in which corresponding imine were made from 3-methyl-3-nitroaniline and 4-methyl-2-nitroaniline respectively and 2-Methoxy-5-trifluoromethoxybenzylidene)-(3-nitrophenyl)amine which was made from 3-nitroaniline present a complete elimination of the regio-isomer.