Technical Field

The present invention relates to an article comprising a batteryless device that nonetheless can generate sufficient light energy to effect cure of a provided photocurable composition that possesses at least one cure mechanism reliant on photoinitiation. Technical Background

Adhesives provide practical solutions for bonding parts. So-called consumer adhesives are commonly used in everyday situations to stick things together, for example in craftwork or to repair broken items. Instant adhesives or 'superglues' are a well-known class of consumer adhesive. Such adhesives are also widely used in industry due to their convenience, speed and the fact that they glue almost every type of substrate.

Superglues are derived from the chemical class of cyanoacrylate (CA) monomers that are formulated into a glue composition. These highly polarised molecules polymerise or 'cure' converting the liquid glue to a strong solid during the bonding process. In use, it appears that no stimulus is applied to invoke the curing reaction, but in fact active species, that are ubiquitous on the surfaces of parts, initiate the polymerisation of CAs. When the user changes the surface-to-volume ratio of the applied drop of instant adhesive by squeezing parts tightly together to confine the drop, the spread-out adhesive is suddenly exposed to a high concentration of such active species from two surfaces and bonding occurs rapidly. This behaviour is unique to CAs earning their reputation as 'super glues' that appear to bond 'as if by magic', in fact, the user is actually invoking 'cure-on-demand' by squeezing the parts together. However CAs do not cure instantly when present on only one substrate and furthermore any excess glue that is exuded from between squeezed parts constitutes a nuisance since it can easily instantly bond to any further substrate that contacts it such as wipes or even one's fingers. CAs clearly do not cure-on-demand on one substrate only - at least not instantaneously.

Another unrelated class of useful consumer repair products finding much popularity in the market are so-called 'liquid plastics' that cure under the action of light, as disclosed in International patent application WO-A-2013/064248, available commercially under the tradename Bondic ^® (www.thegadgetflow.com). These are derived from the chemical class of acrylate monomers and have been formulated with photoinitiators receptive to visible light, which is a user-friendly source of energy and used to invoke cure. Such liquid products are contained in light tight packages and sold together with battery powered light sources, such as blue light emitting diodes (LEDs). The package and LED are generally offered as a handheld tool. The LED device is powered with compact lithium based batteries and it is often detachable from the pack containing the photosensitive composition, which is a squeezable tube with a cannula and a protective cap. Related products are also known with other types of batteries as disclosed in European patent application EP-A-2741897. Refill packs of liquid plastics without the LED device are also offered as part of a kit. The LED devices are also offered separately. These products provide convenient 'cure-on-command' in the sense that the cure is specifically only light induced - they do not function as adhesives per se, unless at least one of the substrates to be united is transparent to visible light. Thus, these 'liquid plastics' are not glues in absence of light and they are not super glues capable of bonding a range of substrates, especially those that are opaque. They can however be used to reinforce a joint by curing a layer of material that wraps around its periphery even if the substrates themselves are non-transparent. Similarly, unlike regular CAs, they can be used to form photocured coatings atop one substrate or, to infill dents or holes in damaged parts when the liquid plastic is usually applied to one substrate and subsequently photocured in a layer- by- layer fashion to build up a bulk solid and fulfil a repair function.

Returning to instant adhesives, it may be logical to contemplate that there is no need for any additional cure mechanism in this class since these are readily initiated by ubiquitous surface species when joining two parts. Nevertheless certain photopolymerisable CAs have been developed and to fulfil very important needs. As such, these adhesives are CAs with an available second cure system which has been designed-in, as disclosed for example in International patent applications WO-A- 98/38260 and WO-A-03/064483, and in European patent application EP-A-0769721 . Such CAs possess the ability to instantly bond most every type of substrate whether transparent or not, and, have the additional feature that they can be cured-on-demand when exposed to light and most advantageously to a 'tack-free' (dry-to-touch) surface which is generally not the case for most acrylic based systems. The photocuring feature can be invoked to solidify excess materials exuded from between substrates and remove its nuisance value, or to purposely provide reinforcement to an already physically bonded joint (since the CA is an actual adhesive unlike liquid plastics, that are not adhesives), or to cure CA applied to one substrate only, for example as a coating. These specialised CAs are a small subset of all CA adhesives available and are currently used in high value-added industrial markets such as electronic assembly or in medical devices for example for the bonding of display parts and hypodermic needles in syringes, as disclosed in Loctite Needle Bonding Design Guide, Henkel Corp. 2004, 2238-LT-3720 604. Such products are not found in the consumer market for a variety of reasons. The recommended storage conditions for such specialised photocurable CAs is 2-8 ^e C, as disclosed in Loctite ^® 4306™ Technical Data Sheet, July 2013, which is not suitable for a consumer product in a retail channel. The specialised CAs products that are available to date are exclusively based on ethyl cyanoacrylate (ECA), which is a lachrymator, odoursome, and its volatile vapours can stain products - features that are less readily managed in the hands of consumers, even if they can be controlled in industry.

In unpublished Patent Application PCT/IB2016/051024 a non- lachrymatory, odourless alkoxyalkyl CA that is an instant adhesive and additionally may be cured by blue-violet light, and stored in ambient conditions, has been described. Such a user-friendly, dual cure adhesive is already highly suited to industrial applications where end users in Original Equipment Manufacturers (OEMs) for example purchase adhesive and use in-house irradiation means to effect photocure, e.g., on manufacturing assembly lines.

However such a dual curing, user-friendly product would also be very convenient, versatile and attractive for consumer use given the already wide acceptance of cure-on-demand 'liquid plastics' on the one hand, and utility of conventional super glues on the other. The product in question would offer the combined features of both of the latter types, particularly since it is curable with a low powered visible LED. Such a product would even offer advantages to consumers over normal lachrymatory super glues based on ECA. However, provision of compact battery powered LED devices to enable the desirable 'cure-on-demand' features, whether for special super glues or liquid plastics, itself presents problems particularly with regard to legislation associated with the packaging, transportation and disposal of battery driven devices, especially those based on lithium metal. Responsible conformance to legislation adds significantly to costs and lengthens product supply lead-times (since air transportation is complex or restricted), making the introduction and frequent replenishment of such products problematic in the fast moving consumer good sector. Aside from the aforementioned issues, devices reliant on batteries only function when their batteries are in good condition and batteries deteriorate with time even if not in use so that on the occasions when a user needs to effect cure of a composition, there is no guarantee that a light source will function sufficiently. These are problems in need of solution to enhance the accessibility especially of a highly versatile product such as an odourless CA that is both adhesive and a liquid plastic and is both user-friendly and environmentally friendly. The need to supply such a product must be at reasonable cost so consumers can benefit and thus must address the difficulties associated with providing an energy source to invoke photocure in a practical manner.

Object of the invention

The object of the present invention is a handheld article used to provide, dispense and cure a photosensitive composition.

Also part of the invention is a method for using that article.

Also part of the invention is a replacement component of that article.

Brief description of drawings

Figure 1 illustrates a non-battery driven prototype device for curing a light sensitive CA adhesive that has been dispensed in two drops (items 1 and 1 c) of approximately equal size at the same time from the same adhesive package under normal room lighting conditions.

Figure 2 illustrates mechanical activation via rotation of a manual crank (item 5) of a non-battery driven prototype device for curing a light sensitive CA adhesive and the irradiation of only one of the two drops previously dispensed. Figure 3 illustrates that the drop of light sensitive CA adhesive is dry to touch following irradiation from the mechanically driven device.

Figure 4 illustrates that the drop of light sensitive that has not been irradiated is still in an uncured liquid state that may be spread out as an uncured liquid film.

Figure 5 illustrates the photocured and non-photocured light sensitive CA adhesive after irradiation of only one of the equivalent initially dispensed drops.

Figure 6 discloses a schematic illustration of a handheld, ergonomically styled device for dispensing and curing light sensitive compositions. Figure 7 discloses a schematic cut-away illustration of a handheld, economically styled device for dispensing and curing a light sensitive adhesive or liquid plastic that uses mechanical means to generate light. The view illustrates gear components, squeezable trigger and ratchet systems to enable a dynamo to power the LED. The position of the adhesive tube is also shown.

Figure 8 represents a magnified view of Figure 7, detailing geometric relationship between movable components. Figure 9 represents a schematic representation of the carriage for the rotatable dynamo with gear parts removed for clarity.

Figure 10 shows schematically the action of dispensing a photocurable composition by squeezing side panels on the device casing (a), and the subsequent step of photocuring the dispensed drop by squeezing the trigger of the batteryless device to energise the LED which is directed at the dispensed drop (b).

Figure 1 1 represents a schematic illustration of an alternative embodiment for the bateryless device for photocurable compositions using showing disposition of a magnet immersed within the photocurable composition.

Detailed description of the invention

The object of the present invention is a handheld article used to provide, dispense and cure a photocurable composition that comprises:

a) a batteryless device that enables electrical energisation of a visible light emitting diode (LED) with a power dissipation comprised in the range 100-200 mW and a wavelength of emission comprised in the range of 365-430 nm, and, b) a photocurable composition responsive to the luminous output power and wavelength of the said batteryless device.

The authors of the present invention have developed a handheld article, comprising a batteryless light source and a photocurable composition, wherein mechanically motion is used to energise an LED that enables cure-on-demand, particularly of visible light sensitive CAs, but also liquid plastics. The article is both user-friendly and environmentally-friendly and has enhanced reliability since it is entirely independent of batteries. In the case where the composition is a CA, the article may be used to effect light cure of an adhesive, sealant, coating, reinforcing agent or filler for repair work, in a range of applications.

The use of batteryless devices in the article of the invention offers many useful features. They provide reliability in end-use, they are environmentally friendly and they may be transported cost effectively and quickly without restriction. Their major disadvantage is their inability to sustain power for long periods relative to devices connected to conventional batteries. It is surprising that thus far such devices have not been anticipated to effect photocuring of liquid plastic or adhesive compositions, since this is an application where all the advantages of batteryless power can be used to overcome problems associated with the cost of assembly, transport, supply and disposal of battery powered devices, and in which the aforementioned disadvantages do not apply, since only occasional use and short bursts of reliable power-on-demand are required in consumer products based on visible light sensitive curable compositions.

Definitions

Non-battery, battery-free or batteryless light source device - are terms of equivalent meaning defining a device that is completely devoid of a battery, but which enables generation of electricity through mechanical means to power a light emitting diode. Excluded from definition are devices that use mechanical energy to charge a battery. Batteryless devices herein described form part of an article, set, kit, or functional package or may be used independently specifically to invoke cure of any type of suitable sensitive photocurable compositions. Kit - a set of articles for a specific purpose.

Set - more than one item or article used in conjunction.

Light sensitive, light curable, photosensitive or photocurable compositions - defines monomers and/or their formulations comprising a photoinitiator system. Said compositions may be converted from a non-solid (liquid, gel etc.) to a solid state, that is represented by the 'cured', polymerised or hardened state. Such compositions may, or may not, possess dual curing characteristics, that is, they may possess only the ability to photocure, or, may possess the ability to cure in more than one way (for example be instantly polymerisable and light curable). Such compositions are sufficiently sensitive to be cured by low powered visible LEDs (those with outputs of approximately 200 mW or less).

Functional composition - defines a composition such as a light sensitive composition that may be used in more than one mode, for example, as an adhesive, as a coating, as a material that can fill-in holes or dents, as a reinforcing agent cured around a joint or, within and around a joint, and as a sealant.

Functional package - defines a package that performs more than the basic function of containing a composition, for example, a package for containing and dispensing a photocurable composition that also has an integrated light source to effect cure of the dispensed composition. A set may also be a functional package if items are co-joined but separable. Cure-on-demand - defines the instigation of an action that transits a non-solid composition into a solidified or cured state only when the end user requires in a brief period of time (some seconds).

Power-on-demand - in the present disclosure defines the generation of electrical power to energise a light emitting diode.

In the present description as well as in the claims, the singular forms "a" and "an" include also the plural reference unless the context clearly indicates otherwise.

In this description, the percentages (%) are expressed in weight/weight unless otherwise indicated, and in the compositions, the sum of the percentages of the different components is adjusted to add up to 100%.

Batteryless device

The batteryless device of the present invention provides electrical energy to energise a visible light emitting diode (LED) to invoke cure of the photocurable composition.

In a preferred embodiment the batteryless device is the package for the photocurable composition.

In another preferred embodiment the batteryless device and the photocurable composition either are:

- linked or joined together, but separable, or, - independent, but associated with each other in the form of a kit.

In the article of the invention, the batteryless device is activated either by:

- hand winding a dynamo or motor with a crank, or

- compressing or squeezing a trigger mechanism repeatedly to drive a dynamo, or

- shaking by hand to produce electromagnetic induction.

In a preferred embodiment the crank may be foldable.

In a preferred embodiment, the batteryless device comprises additionally a capacitor or supercapacitor to store electrical energy thus mechanically generated, and a switch.

In one preferred embodiment, the batteryless device, which is handheld, is activated by a wind-up crank or a trigger type crank as illustrated by Figures 1 and 2, item 5. Actuating a crank drives a motor or dynamo that supplies electrical current to the light emitting diode (Figure 1 , item 4). The act of winding a crank, or hand compressing on a trigger mechanism starts rotation of a gearing mechanism (Figure 1 , item 2) comprising a series of cogs within the device casing. In the case of a trigger type crank, a spring returns the crank to its original position to allow further compressions. The gear mechanism transfers energy to a flywheel that forms part of a dynamo, or armature of a motor (for example Figure 1 , item 3), which spins a magnet that generates an electric current in a copper coil. The induced current is caused by the changing magnetic flux produced by the rotating magnet in the vicinity of copper wire coils in the dynamo or small electrical motor, based on electromagnetic principles well known to those skilled in the art. In such crankable preferred embodiments, the batteryless device may be housed in a casing that is co-joined to a package containing the photosensitive composition and the co-joined batteryless device may be separable from the packaged photocurable composition. Alternatively it may be entirely independent from the said packaged photosensitive composition and both packaged items offered in a kit. Still further, the independently packaged photosensitive composition may be encased within the housing that contains its gearing mechanism.

Figures 1 to 5 illustrate the photocure of a visible light sensitive cyanoacrylate composition included in the article of the present invention. The composition is dispensed in normal artificial room lighting as two drops illustrated in the Figures as items 1 and 1 C, wherein 1 C is a control sample. Figure 2 illustrates light being produced (item 6) following the action of rotating vigorously the hand crank 5. The light is of the wavelength range 400-420 nm and impinges upon only drop 1 of the photocurable composition. After 3 seconds or so continuous irradiation from a distance of approximately 5 cm above the composition, curing is evident since drop 1 is dry to touch and polymerised to a solid adhering strongly to the paper substrate as illustrated in Figure 3. The drop that has not been irradiated, 1 C, is uncured as seen in Figure 4 and Figure 5 since it can be spread as a liquid.

Figure 6 illustrates a preferred embodiment of the present invention illustrating a casing (7), with a compressible trigger (8) and squeezable side panels (9). The casing contains a tube, which is covered by protective cap (10). An LED (4) is shown positioned at an opening in the casing. Figure 7 illustrates an internal view of the device of Figure 6. The packaged composition is contained in tube (1 1 ). The gear mechanism is illustrated in part by item (2) connected to dynamo (13). The trigger mechanism (14) is connected by a linear gear (12) that drives (2) and (13) to power LED (4). Figure 8 illustrates how the gear mechanism meshes in more detail. Figure 9 shows the device of Figure 8 with the gear mechanism removed to expose the carriage (15) that carries the dynamo. Also shown in Figure 9 is the dispensing cannula (16), which is light opaque and preferably passivated internally. Figure 10a illustrates how dispensing of the photosensitive composition is effected by the action (17) of squeezing side panels (Figure 1 , item 9). In Figure 10b the action (18) of compressing (repeatedly) the trigger mechanism (Figure 1 , item 8) energises the LED to effect photocure of the dispensed composition.

Another type of batteryless device may energise a visible light emitting diode through an alternative mechanical means. Thus a so-called Faraday Flashlight (see for example US patent 5,975,714) exploits hand shaking of a casing containing a permanent magnet in a hollow tube around which a copper coil is wound in a section of the casing. Moving a magnet in a coil induces an electric current that is used to power- on the LED directly, or, that is used to charge a supercapacitor that stores the current then directs it to the LED when switched into a circuit, so continuous shaking is not required. In this type of device the magnet is moving in a hollow body filled with a fluid, which is air. However, it was found that a liquid fluid, such as a photosensitive composition may be used to replace all or part of fluid air without impeding operation of the device provided the viscosity of said formulation is not excessively high - a preferred viscosity range would be below 300 cps at ambient temperature. The casing of the device is compatible with the said composition, for example high-density polyolefin, or, if metallic the casing should be non-ferrous, for example aluminium. To ensure compatibility with the formulation of the photosensitive composition, the magnet may be coated with a thin cover of a resin or polymer - for example PTFE or Parylene (poly(p-xylylene) polymers). In such an embodiment of the present invention, the hollow chamber is fashioned to allow filling and dispensing of the photocurable composition.

In an alternative embodiment to the aforementioned, a magnet may be placed into a cylindrical tube of photocurable composition, such that the magnet still has free motion. A schematic illustration of such an article is shown in Figure 1 1 . Dispensing relies on the relatively low viscosity of the photocurable composition since minimum squeezing of the chamber walls is recommended so that the chamber does not deform and prevent free motion of the magnet within. Suitable tubes may or may not have cylindrical plastic inserts for example as illustrated in US-A-2009/0001098. In this embodiment the package is a tube (19) containing the photocurable composition (26) with a magnet (23) inside being further inserted in to a further outer package that is a cylinder casing (21 ) comprising a copper coil (22) wound in one section and electrically connected (25) to an LED (24), preferably via a supercapacitor (not shown for clarity). One end of the packaged composition has a cannula (not shown) protected by a removable cap (20) from where from where the composition may be dispensed. When the tube containing the photocurable composition and magnet is inserted into the outer package containing a copper coil electrically connected to the LED and the design is arranged so that shaking the thus assembled items enables the magnet to transverse through the coil, albeit within an independent tube, an electrical current may be generated to energise the LED, so that the photosensitive composition may be cured once dispensed and irradiated.

Combined batteryless devices and packages of photocurable compositions in any of the embodiments described may be considered as 'functional packages' since they perform more than one function only. Thus an article comprising such components enables dispensing and cure of photosensitive compositions without recourse to batteries.

Light Emitting Diodes for curing photosensitive compositions

Light emitting diodes operating in the blue-violet range of the visible spectrum are most suited to the present invention. Such LEDs have substrates based on the semiconductors zinc selenide, indium gallium nitride, silicon carbide and silicon. They comprise clear moulded shells designed to boost the light emission from the semiconductor core by acting as a diffusing lens, allowing light to be emitted at a much higher angle of incidence from the light cone of the bare semiconductor chip alone. Various physical sizes of LEDs are possible. In the present invention the diameter of the LED is in the range 3-5 mm and generally only one LED is required.

The LED emits in the wavelength range of 365-430 nm, preferably in the range of 400-420 nm, with a power dissipation in the range of 100-200 mW, preferably in the range of 120-150 mW. Viewing angle of the LED ensures generally a focused light emission, preferably in the range of 10 to 20 degrees. Preferably, LED has a luminous intensity in the range of 20--100 Im depending on angles.

Photocurable composition

The handheld article according to the invention includes a photocurable composition, which comprises:

a) at least one cyanoacrylate monomer and/or at least one acrylate monomer, and b) a visible light photoinitiator system. Cyanoacrylate monomer

In a preferred embodiment the cyanoacrylate monomer is selected from Ci-C ₈ linear or branched alkyl cyanoacrylic esters, alkoxyalkyl cyanoacrylic esters and alkylsilyloxyalkyl cyanoacrylic esters.

In a more preferred embodiment, alkoxyalkyl cyanoacrylic esters and alkylsilyloxyalkyl cyanoacrylic esters are defined by formula (I):

(I) (II)

wherein A is the CN group and D is an ester group defined by formula (II),

wherein n = 1 -3, R ⁷ is selected from the group consisting of H and Me, and R ⁸ is selected from the group consisting of Si(Me ₃ ) ₃ , and a Ci-C ₆ linear or branched alkyl chain.

Among alkoxyalkyl cyanoacrylic esters and alkylsilyloxyalkyl cyanoacrylic esters the following are preferred: 2-methoxyethyl, 2-ethoxyethyl, 2- propoxyethyl, 2-butoxyethyl, 2-isopropoxyethyl, 2-hexyloxyethyl, 2-amyloxyethyl, 2- ethoxybutyl, 2-methoxypropyl, and 2-(1 -methoxy)propyl, trimethylsilyloxyethyl, hexamethyldisiloxanoxyethyl. Other examples of alkoxyalkyl type monomers are described in the International patent application WO-A-02/053666.

The alkoxyalkyl cyanoacrylates are particularly preferred in the article of the invention because they are low in odour and are non-staining and non-irritant. In a preferred embodiment, alkoxyalkyl cyanoacrylic esters are selected from 2- methoxyethyl, 2-ethoxyethyl, 2-propoxyethyl, 2-butoxyethyl, 2-isopropoxyethyl, 2- hexyloxyethyl, 2-amyloxyethyl, 2-ethoxybutyl, 2-methoxypropyl, and 2-(1 - methoxy)propyl.

Unpublished PCT/IB2016/051024, which is incorporated here in full by reference, describes a blue light sensitive photocurable methoxyethyl cyanoacrylate compositions that are suitable to industrial and consumer applications since they are stable under room temperature conditions of storage and are non-irritants and have low odour characteristics. Such compositions are photocurable with the same battery driven LED devices that are used for liquid plastics.

Acrylate monomer

In a preferred embodiment the acrylate monomer is selected from hydroxyethyl acrylate, isobornyl acrylate, poly(ethylene oxide) diacrylates, bisphenol A epoxy diacrylate, bisphenol A epoxy ethoxylated diacrylates, pentaerythritol tetraacrylate, pentaerythritol triacrylate, 1 ,6-hexanediol diacrylate.

These acrylate monomers are present in commercially available so- called liquid plastic products including UV and visible light photoinitiating systems, such as Bondic ^® , 5-Second Fix ^® , Blufixx ^® , Proformic ^® and MD UV-Star ^® . Thus far these products exploit only free radical initiation mechanisms.

Combination of cyanoacrylate monomers and acrylate monomers

Photocurable cyanoacrylate formulations may contain also acrylate monomers to constitute mixed systems that cure by independent mechanisms. That is, cyanoacrylates are initiated by nucleophilic or anionic species, whereas acrylates are initiated by free radical species. However, even though cyanoacrylates are initiated by distinct species from acrylates, the photoinitiating system they exploit usually comprises an initiator and a co-initiator, and in this case the co-initiator is in fact a free radical initiator that first decomposes to produce radicals that then react with the second compound to produce actual initiating species that are not radicals (see PCT/IB2016/051024 and references therein). Thus, in compositions containing cyanoacrylate and acrylate monomers, the photoinitiating system for the former is adequate to initiate both mechanisms of polymerisation.

Photoinitiator system

Visible light sensitive free radical initiators are well known and have been described extensively in the literature, for example, Fouassier et al., Progress in Organic Coatings, 2003, 47, 16-36, and, Shao et ai, Polymer Chemistry, 2014, 5, 4195-4210.

Well-known radical photoinitiators with sensitivity in the UVA-visible region are (2,4,6-trimethylbenzoyl)diphenyl phosphine oxide, or PO', defined by formula (III), and bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide) or BAPO, defined by formula (IV), the former shows sensitivity in the UVA-visible region (about 365 nm) and the latter has enhanced absorbance in the visible region up to about 425 nm:

(III) (IV)

Under irradiation in this region these acylphosphine oxide initiators form radicals by bond cleavage.

An example of a visible light initiation system that requires hydrogen atom transfer to form radicals is camphorquinone (CQ) that absorbs in the visible region (-468 nm) and requires an amine synergist. Whereas amine synergist can be used in acrylic formulations, they cannot be used in any part of the photoinitiation system of cyanoacrylate formulations due to their nucleophilicity.

Examples of photocurable compositions comprising mixtures of cyanoacrylates and acrylates are disclosed in the abovementioned unpublished PCT patent application together with reference to visible light photocuring systems based on acyl germane type photoinitiators used in conjunction with metallocenes such as ferrocene. Preferred photoinitiators and ferrocene derivatives are illustrated by structures (V) and (VI) respectively and typically in the concentration range 240-1000 ppm and, 200-300 ppm respectively:

(VI)

where R ¹ is -H

Since acyl germanes are efficient visible light photonitiators for radical polymerisation of acrylates per se (see EP-A-1905415) combinations of ferrocene with the aforementioned initiators allow efficient photoinitiation of systems comprising CAs admixed with acrylates.

In the handheld article of the invention, the photoinitiator system is selected from the group consisting of: compound of formula (V), compound of formula (III), compound of formula (IV), and combinations thereof with compound of formula (VI).

Additional components

In a preferred embodiment the photocurable composition comprises additionally an agent selected from the group comprising: thickeners, rheology modifiers, stabilisers, accelerators, and mixtures thereof.

Thus, photocurable formulations based on CAs may further be formulated with ingredients well known to those skilled in the art, for example poly(methyl methacrylate) and polyvinyl chloride-co-acetate) are used to thicken (typically in range 1 -8% w/w depending on target viscosity), hydrophobic fumed silica is used to build thixotropic properties if desired (typically 2-5% depending on target thixotropy and concentration of polymeric thickener if present), radical stabilisers are used such as hydroquinone or methoxy phenol (typically 50-4000 ppm and preferably 150-400 ppm), and Lewis acid stabilisers such as BF ₃ derivatives (for example BF ₃ . etherate) and S0 ₂ (typically 3-10 ppm of pure substance). Bronsted acid stabilisers such as methane sulfonic acid (MSA) may also be used at low levels (typically 5-10 ppm). CA compositions may also contain accelerators to promote speed on porous or acidic surfaces (surfaces such as certain woods for example). Crown ethers are commonly used in the art such as dibenzo-18-crown-6, typically at concentrations of 0.1 -0.2% w/w.

Photocurable acrylic formulations only require radical stabilisers such as hydroquinone or methoxy phenol or related compounds at similar concentration ranges. These may also be thickened and rendered thixotropic in the same manner as CAs.

The present invention discloses an article that serves to enable curing of a visible light sensitive composition with a batteryless LED device. Independence from batteries, in electrically powered consumer products, offers many advantages with regard to transportation, ready supply and ease of disposal after final use which increases accessibility and reduces cost to the end user, especially for highly versatile bonding, sealing, reinforcing and coating compounds. Configurations of the handheld article

In a preferred embodiment the photocurable composition is contained in a vessel that is opaque to ultraviolet and visible light, and has an associated cap and cannula or internally threaded nozzle to enable dispensing of the photocurable composition that is either:

- a directly or indirectly squeezable aluminium collapsible tube with an externally threaded pedestal which is foil sealed and has optionally an internal resin coating and/or a plastic insert inside, and wherein said foil seal may be pierced open by engaging the associated nozzle by screwing said threaded parts together, or

- a plastic tube.

In a preferred embodiment the photocurable composition is contained in a tube or bottle, opaque to ultraviolet and visible light, and has an associated brush cap.

In a preferred embodiment the batteryless device is of the induction type comprising a magnet confined in a hollow chamber that is movable through a coil that encircles the chamber by the action of hand shaking, wherein the chamber functions as a vessel to contain the photocurable composition itself and has optionally an externally threaded foil sealed pedestal, or an integrated cannula.

In a preferred embodiment the handheld article of the invention enables the photocurable composition to be dispensed via either a cannula or an internally threaded nozzle that has a protective and removable cap.

In a preferred embodiment the handheld article of the invention comprises:

a) the photocurable composition comprised either in a plastic tube with a preassembled cannula and cap, or in a foil sealed aluminium tube with an externally threaded pedestal and an associated cap and nozzle with internal threads that match those on the pedestal and enable piercing of the said foil seal on engaging by screw action, either of which contain a permanent rare earth magnet within, optionally the magnet is polymer coated, and

b) a casing comprising

- an open ended hollow cylindrical chamber,

- a copper coil wrapped around a section of said cylindrical chamber connected to a an electrical circuit that enables induced electric current to flow and energise a visible light emitting diode, and

- a visible light emitting diode.

In a preferred embodiment the handheld article of the invention further comprises one or two squeezable side panels inlaid in the casing, such that said panels are positioned to coincide with the position of an underlying encased aluminium or plastic tube, to enable indirect squeezing thereof to dispense the photocurable composition contained therein.

Method for using the article

A method for using the article of the invention also forms part of the invention.

In a preferred embodiment the method for using the article of the invention comprises the steps of:

1 ) removing a protective cap or brush cap,

2) optionally assembling a screw-on nozzle to pierce a foil sealed aluminium tube,

3) dispensing a photocurable composition from a tube or bottle to at least one substrate,

4) optionally reclosing the tube with a cap,

5) optionally spreading the dispensed photocurable composition as a coating,

6) energising the light emitting diode,

7) directing the emitted light at the dispensed photocurable composition to invoke cure.

8) closing the tube with a cap if not previously closed,

wherein the photocurable composition comprises at least one cyanoacrylate monomer alone or in combination with at least one acrylate monomer.

In a more preferred embodiment, said coating is applied to living tissue such as skin or finger or toenails.

In a preferred embodiment the method for using the article comprises the steps of: 1 ) removing a protective cap or brush cap,

2) optionally assembling a screw-on nozzle to pierce a foil sealed aluminium tube,

3) dispensing a photocurable composition from a tube or bottle, to at least one substrate

4) optionally reclosing the tube with a cap,

5) optionally spreading the dispensed photocurable composition,

6) assembling parts or substrates whether transparent to visible light or otherwise, and optionally,

7) energising the light emitting diode,

8) directing the emitted light through substrates transparent to visible light or at any excess dispensed of the photocurable composition to invoke cure to bond, reinforce or seal substrates,

9) closing the tube with a cap if not previously closed,

wherein the photocurable composition contain only at least one cyanoacrylate monomer and no acrylate monomer.

In a preferred embodiment the method for using the article of the invention, comprises the steps of:

1 ) removing a protective cap or brush cap,

2) optionally assembling a screw-on nozzle to pierce a foil sealed aluminium tube,

3) dispensing a photocurable composition from a tube or bottle into a scratch, hollow, fissure, dent or hole,

4) optionally reclosing the tube with a cap,

5) energising the light emitting diode,

6) directing the emitted light at the dispensed photocurable composition to invoke cure,

7) optionally repeating the process to enable a repair,

8) closing the tube with a cap if not previously closed,

wherein the photocurable composition comprises at least one cyanoacrylate monomer alone or in combination with at least one acrylate monomer.

In a preferred embodiment the article of the invention it is contained in a secondary package, which more preferably is a presentation box, a presentation tin, a folding cardboard box or a blister pack.

Replacement component

A replacement component of the article of the invention also forms part of the invention. In a preferred embodiment the replacement component is a package of photocurable composition.

The invention comprises the following embodiments:

1 .- A handheld article used to provide, dispense and cure a photocurable composition, characterized in that it comprises:

a) a batteryless device that enables electrical energisation of a visible light emitting diode (LED) with a power dissipation comprised in the range 100-200 mW and a wavelength of emission comprised in the range of 365-430 nm, and, b) a photocurable composition responsive to the luminous output power and wavelength of the said batteryless device.

2. - An article according to embodiment 1 , characterized in that the batteryless device is the package for the photocurable composition.

3. - An article according to embodiment 1 , characterized in that the batteryless device and the photocurable composition either are:

- linked or joined together, but separable, or,

- independent but associated with each other in the form of a kit.

4. - An article according to anyone of embodiments 1 to 3, characterized in that the batteryless device is activated either by:

- hand winding a dynamo or motor with a crank, or

- compressing or squeezing a trigger mechanism repeatedly to drive a dynamo, or

- shaking by hand to produce electromagnetic induction.

5. - .- An article according to embodiment 4, characterized in that the batteryless device comprises additionally a capacitor or supercapacitor to store electrical energy thus mechanically generated, and a switch.

6. - An article according to anyone of embodiments 1 to 5, characterized in that the photocurable composition comprises:

c) at least one cyanoacrylate monomer and/or at least one acrylate monomer, and d) a visible light photoinitiator system.

7. - An article according to claim 6, characterized in that the photocurable composition comprises additionally an agent selected from the group comprising: thickeners, rheology modifiers, stabilisers, accelerators, and mixtures thereof.

8. - An article according to embodiment 6 or 7, characterized in that the cyanoacrylate monomer is selected from Ci-C ₈ linear or branched alkyl cyanoacrylic esters, alkoxyalkyl cyanoacrylic esters and alkylsilyloxyalkyl cyanoacrylic esters. 9. - An article according to embodiment 8, characterized in that the alkoxyalkyl cyanoacrylic esters are selected from 2-methoxyethyl, 2-ethoxyethyl, 2-propoxyethyl, 2- butoxyethyl, 2-isopropoxyethyl, 2-hexyloxyethyl, 2-amyloxyethyl, 2-ethoxybutyl, 2- methoxypropyl, and 2-(1 -methoxy)propyl.

10. - An article according to embodiment 6 or 7, characterized in that the acrylate monomer is selected from hydroxyethyl acrylate, isobornyl acrylate, poly(ethylene oxide) diacrylates, bisphenol A epoxy diacrylate, bisphenol A epoxy ethoxylated diacrylates, pentaerythritol tetraacrylate, pentaerythritol triacrylate, 1 ,6-hexanediol diacrylate.

1 1 . - An article according to any of embodiments 6 to 10, characterized in that the photoinitiator system is selected from the group consisting of:

- an acyl germane photoinitiator of structure (V)

(V)

wherein R ³ is -H or -Me,

- an acyl phosphine oxide selected from (2,4,6-trimethylbenzoyl) diphenyl phosphine oxide (structure (III)) or bis(2,4,6-trimethylbenzoyl) phenylphosphine oxide (structure (IV)),

(III) (IV)

and

combinations of either acyl germane of formula (V) or acyl phosphine oxide of formula (III) or (IV) with a ferrocene of structure (VI):

(VI)

where R ¹ is -H

12. - An article according to anyone of embodiments 1 to 1 1 , characterized in that the photocurable composition is contained in a vessel that is, opaque to ultraviolet and visible light, and has an associated cap and cannula or internally threaded nozzle to enable dispensing of the photocurable composition that is either:

- a directly or indirectly squeezable aluminium collapsible tube with an externally threaded pedestal which is foil sealed and has optionally an internal resin coating and/or a plastic insert inside, and wherein said foil seal may be pierced open by engaging the associated nozzle by screwing said threaded parts together, or

- a plastic tube.

13. - An article according to anyone of embodiments 1 to 1 1 , characterized in that the photocurable composition is contained in a tube or bottle, opaque to ultraviolet and visible light, and has an associated brush cap.

14. An article according to embodiment 1 , characterized in that the batteryless device is of the induction type comprising a magnet confined in a hollow chamber that is movable through a coil that encircles the chamber by the action of hand shaking, wherein the chamber functions as a vessel to contain the photocurable composition itself and has optionally an externally threaded foil sealed pedestal, or an integrated cannula.

15. An article according to embodiment 14, characterized in that it enables the photocurable composition to be dispensed via either a cannula or an internally threaded nozzle that has a protective and removable cap.

16. - An article according to embodiment 1 , characterized in that it comprises:

a) the photocurable composition comprised either in a plastic tube with a preassembled cannula and cap, or in a foil sealed aluminium tube with an externally threaded pedestal and an associated cap and nozzle with internal threads that match those on the pedestal and enable piercing of the said foil seal on engaging by screw action, either of which contain a permanent rare earth magnet within, optionally the magnet is polymer coated, and

b) a casing comprising - an open ended hollow cylindrical chamber,

- a copper coil wrapped around a section of said cylindrical chamber connected to a an electrical circuit that enables induced electric current to flow and energise a visible light emitting diode, and

- a visible light emitting diode.

17. - An article according to embodiment 1 or 12 that further comprises one or two squeezable side panels inlaid in the casing, such that said panels are positioned to coincide with the position of an underlying encased aluminium or plastic tube, to enable indirect squeezing thereof to dispense the photocurable composition contained therein.

18. - An article according to anyone of embodiments 1 to 17, characterized in that it is contained in a secondary package.

19. - An article according to embodiment 18, characterized in that the secondary package is a presentation box, a presentation tin, a folding cardboard box or a blister pack.

20. - Method for using an article of embodiment 1 , characterized in that it comprises the steps of:

1 ) removing a protective cap or brush cap,

2) optionally assembling a screw-on nozzle to pierce a foil sealed aluminium tube, 3) dispensing a photocurable composition from a tube or bottle to at least one substrate,

4) optionally reclosing the tube with a cap,

5) optionally spreading the dispensed photocurable composition as a coating,

6) energising the light emitting diode,

7) directing the emitted light at the dispensed composition to invoke cure.

8) closing the tube with a cap if not previously closed,

wherein the photocurable composition comprises at least one cyanoacrylate monomer alone or in combination with at least one acrylate monomer.

21 . - Method according to embodiment 20, characterized in that said coating is applied to living tissue such as skin or finger or toenails.

22. - Method for applying an article of embodiment 1 , characterized in that it comprises the steps of:

1 ) removing a protective cap or brush cap,

2) optionally assembling a screw-on nozzle to pierce a foil sealed aluminium tube, 3) dispensing a photocurable composition from a tube or bottle to at least one substrate, 4) optionally reclosing the tube with a cap,

5) optionally spreading the dispensed photocurable composition,

6) assembling parts or substrates whether transparent to visible light or otherwise, and

7) optionally, energising the light emitting diode, and directing the emitted light through substrates transparent to visible light or at any excess dispensed composition to invoke cure to bond, reinforce or seal substrates,

8) closing the tube with a cap if not previously closed,

wherein the photocurable composition contain at least one cyanoacrylate monomer and no acrylate monomer.

23. - Method for applying an article of embodiment 1 , characterized in that it comprises the steps of:

1 ) removing a protective cap or brush cap,

2) optionally assembling a screw-on nozzle to pierce a foil sealed aluminium tube, 3) dispensing a photocurable composition from a tube or bottle into a scratch, hollow, fissure, dent or hole,

4) optionally reclosing the tube with a cap,

5) energising the light emitting diode,

6) directing the emitted light at the dispensed composition to invoke cure,

7) optionally repeating the process to enable a repair,

8) closing the tube with a cap if not previously closed,

wherein the photocurable composition comprises at least one cyanoacrylate monomer alone or in combination with at least one acrylate monomer.

24. - Replacement component of an article according to anyone of embodiments 1 to 17.

25. - Replacement component according to embodiment 24, characterized in that it is a package of photocurable composition.

Next, several examples of the invention are provided for illustrative purposes that are understood to be non-limiting.

Examples

Example 1 : Preparation of light sensitive odourless CA

A sample of a photocurable odourless CA was prepared according to the methods described in PCT/IB2016/051024, for example, by mixing CA monomer, thickener, metallocene and germane species at room temperature in light shielded opaque high-density polyethylene (HDPE) bottles. Stock solutions and dilutions were used to ensure accuracy of transfer of any species used in low concentrations. Ferrocene was used at a concentration of 200 ppm and the germane species known as Ivocerin™ (Synthon Chemicals GmbH & Co. KG) at a concentration of 750 ppm. Methoxyethyl CA monomer was synthesized according to a known method, as the one described, for example, in International patent application WO-A-01/36380.

The quantitative composition of the formulation is disclosed in Table I:

TABLE I

operating at 410 nm with a power dissipation of 120 mW and a luminous intensity of -60 Im (at cone angle of 10°). The diode was provided by Tongjia Optoelectronics Technology Co., Ltd. A dispensed drop of the formulation cured in approximately 3 seconds after irradiating with the LED held approximately 5 cm from the sample. After photocure, the cured sample was completely dry to touch.

Example 2: Preparation of a windable batteryless light source

A commercially available science toy, which is a batteryless lamp was purchased (Green Science 'Dynamo Torch' from 4M Industrial Development Ltd. available from Amazon) and then modified. The original green lamp was replaced by the LED (Figure 1 , item 4) specified above so that light at 410 nm could be generated by hand cranking the batteryless device (Figure 1 , item 2). When the crank was rotated continuously the small motor (Figure 1 , item 3) generated energy to illuminate the LED brightly.

The commercial device could be readily modified with a microdynamo (Maxon Motor Iberica s.a. Part 1 18391 ) based on high strength rare earth magnets that compress the geometry of the design. The motor was cranked mechanically through plastic gears.

Example 3: Photocurinq an odourless CA with a windable batteryless light source

Two drops of the formulation disclosed in Example 1 were dispensed on a sheet of paper about 15-20 cm apart under normal ambient conditions and normal ambient room light as illustrated in Figure 1 by items 1 and 1 C where 1 C is the 'control' drop.

The modified device described in Example 2 was activated by hand cranking (Figure 2, item 5) causing the LED to illuminate (Figure 2, item 6). Adhesive drop 1 (Figure 1 ) was exposed to the so-generated light for 3 seconds, whereas control drop 1 C (Figure 1 ) was not. After photoexposure of drop 1 (Figures 1 and 2), the adhesive was fully cured and dry to touch as illustrated in Figure 3. In contrast, the control drop 1 C that had only been exposed to ambient room lighting conditions during the course of the experiment, was not cured and remained as a liquid that could be spread out when wiped with a finger as illustrated in Figure 4. Figure 5 illustrates the final state of the two equivalent drops of odourless CA formulation 1 and 1 C after the photocuring of drop 1 .

Example 4: Photocuring a liquid plastic with a windable batteryless light source

The experiments disclosed in Example 3 were repeated but replacing the odourless CA with a liquid plastic. The liquid plastic was a commercial sample of Bondic ^® available from http://notaglue.com.

After 3 second exposure using the modified device described in

Example 2 the sample drop was cured.

Example 5: Preparation of a shakeable batteryless light source

An induction type batteryless torch was purchased from Amazon (Everlife Light's Faraday Light). This comprised a magnet within a hollow body around which was wrapped a copper coil in one section. The coil was connected to a white LED bulb. The device also contained a supercapacitor. The white LED was removed and replaced with another operating in the wavelength range 400-420 nm with power dissipation of approximately 120 mW.

The modified torch was used to invoke photocure in both cyanoacrylate composition of Example 1 and the commercially available Liquid Plastic Bondic ^® . The time to invoke photocure in both cases was about 3-5 seconds when the light was held approximately 5 cm from each sample.

Example 6: Preparation of a shakeable batteryless light source containing a photocurable composition and curing thereof

The modified lamp torch of Example 5, was further modified to form a prototype package for the photocurable composition. Thus a hole was drilled in the hollow body of the commercial torch. A photocurable formulation such as that of Example 1 was filled into the hollow body of the torch to fill approximately 75% of the hollow space. The hole was plugged with a small stopper. The device was shaken and while the torch switch was left switched in the On' position. The LED was energised and irradiated so that the formulation fluid did not impede the motion of the internal magnet. Drops of the photocurable composition were dispensed from the previously drilled and unplugged hole, which was then reclosed. The prototype device was shaken again for about 30 seconds with the modified visible LED switched in the 'off position. After shaking, the torch was switched on and a bright light emanated from the LED enabling photocure of the dispensed composition.