AU2015203689B2 - Production of elastomeric films - Google Patents

Abstract

A method for producing multi-layered elastomeric film or article, the method comprising: (i) dipping a mould into a 5 composition for producing an elastomeric film having a total solids content of between 5% - 40% to produce a layer of elastomeric film composition on the mould, (ii) partially drying the layer of elastomeric film composition on the mould to reduce the total water content of the 10 elastomeric film composition to a level of not less than 22%, (iii) dipping the mould coated with the partially dried layer of elastomeric film composition into a composition for producing an elastomeric film having a total solids content of between 5% - 40% to produce a 15 further layer of elastomeric film composition on the mould, (iv) optionally repeating the partial drying step (ii) and the further dipping step (iii), and (v) drying and/or curing the layers of elastomeric film composition on the mould,

Description

2015203689 01 Μ 2015

FRDSUCfXON OF ELASTOMERIC FILMS 15

The preseat application is a divisional application from Australian Patent Application No. 2009339262, the entire 5 disclosure of which is incorporated into the present specification by this cross-reference.

FIELD 10 The present invention relates to methods for producing elastomeric films. The method may be used to produce elastomeric film articles such as gloves.

BACKGROUND

Elastomeric articles such as gloves may be manufactured from natural rubber or synthetic equivalents. The common process of manufacture involves dipping a shaped mould info a tank containing the natural rubber latex or synthetic polymer to form an elastomeric film on the mould. A single dipping process can produce elastomeric films with a high probability of having or developing defects, 25 such as a weak spots or pin holes. This can cause problems for products such as gloves as the weak spots or pin holes may expose the wearer to infection or chemical permeation depending on the application. Theoretically multiple dipping can be performed to avoid or limit the 30 risk of defects such as these, but the elastomeric films produced are generally thicker, which is undesirable for products such as gloves due to the reduced sensitivity to the wearer* Another problem associated with multiple dippihg methods is that there can be poor adhesion between 35 the individual layers of elastomeric film, which increases the risk of pin-hole/barrier defects and may reduce the durability of the elastomeric film due to delamination

i«3HMatiefS)PaC1«.AU,: JACOilgLS 2 2015203689 01 Jul 2015 between the individual layers, A further problem can be pooi- pick-up of the latex composition onto the pre-dipped layer on the mould. 5 There is a need to develop an improved method for producing multilayer elastomeric film products, such as gloves, which results in the production of products with improved qualities, 10 It is desirable for the process to be capable of application to a wide range of polymeric compositions for forming elastomeric films. In some instances, it is desirable for the product to be free of chemical irritants, including accelerators in particular. When 15 accelerators are not used, the process needs to be capable of forming elastomeric films and articles which still have the required properties of the desired thickness, good coating of film layers onto underlying layers, minimisation of pin-hole defects, mechanical strength, 20 durability and/or freedom from delamination between individual layers .

According to the present application there is provided a method for producing multi-layered elastomeric film or article, the method comprising; 30 (i) dipping a mould into a composition for producing an elastomeric film having a total solids content of between 5% - 40% to produce a layer of elastomeric film composition on the mould, (11} partially drying the layer of elastomeric film composition on the mould to reduce the total water content of the elastomeric film composition to a level of not less than 22%, (iii) dipping the mould coated with the partially dried layer of elastomeric film composition into a

AS53S53J jAfXiuPiS ..3. 2015203689 01 Μ 2015 40% composition· for producing an elastomeric film having a total solids content of between 5% -to produce a further layer of elastomeric film composition on the mould, im (ν) optionally repeating the partial drying step (i: and the further dipping step {ill}, and drying and/or curing the layers of elastomeric film composition on the mould. 10 The elastomeric film or article may be in the form of a glove, condom, balloon or another product. When the elastomeric article is a glove, the mould is suitably a glove or hand"shaped mould. 15 The present application also provides elastomeric films and articles, such as gloves, condoms or balloons, produced by the method.

The method may further comprise the steps of: 20 (a) dipping the mould into a coagulant containing multivalent ions in solution, {b} drying or partially drying the coagulant-dipped mould, prior to step (i). 25

Typically, during the partial drying step (11), the maximum film surface temperature of the elastomeric films composition on the mould is between 25°C-85t>C. 30 It has been found by the applicant that it is very important to only partially dry each layer of elastomeric film composition on the mould prior to applying a subsequent layer of elastomeric fi1m Composition, In particular, the applicant has found that it is important 35 that the water content in the partially dried elastomeric film composition on the mould is no less than 22% when the mould is dipped again to form a further layer. The water 4 2015203689 01 Μ 2015 content of not less than 22% reflects that some liquid remains in the layer of elastomeric film composition.

This water content enables subsequent layers of elastomeric film composition to be ^applied and to adhere, 5 spread evenly across and penetrate into the underlying layer, to assist in the avoidance of pin-point or barrier defects and de~laminating in the film. This also assists in the durability of the film. Previously, it was considered necessary to completely dry each layer of 10 elastomeric film composition when preparing a multilayered elastomeric film. However, this is not the case, and surprisingly improved properties flow from partially drying the elastomeric film composition under the conditions referred to in step (ii) prior to the 15 application of subsequent layers of elastomeric film composition.

The dipping is performed at least twice, with the intermediate partial drying step as described above. As 20 indicated in step (iv), steps {ii} and (iii} can optionally be repeated one or more times, to produce films and articles comprising 3 or more layers. The final elastomeric film or article can, for example, comprise 2 to 15 layers, preferably 2 to 10 layers, more preferably 3 25 to 6 layers of corapdsition,

DlTAILED description

The method for producing multi-layered elastomeric film or 30 articles is suitable for manufacturing polymer gloves, including "disposable gloves". Conventionally, polymer globes are used to avoid contamination, i.e, in food hancling or in hospitals where there is a risk of tidnsfer of infection on contact with sites of infection. Polymer 35 globes are also used to avoid the transfer of disease via skin, contact between patient and examiner, when physical examination is carried out.

Disposable gloves are usually thinner than non-disposable 2015203689 01Jul2015

where the reduced cost of manufacture of a thinner glove means it is cost-effective to dispose of the glove after a single or several uses, Longer-lasting: gloves tend to be thicker, for greater durability and lifespan, Both disposable and longer-lasting gloves can be produced using the method of the present application. 10 The physical properties of disposable gloves, usually include a snug tight fit of a thin elastomeric film to facilitate sensitivity to touch by the wearer. At the same time, sufficient elongation is required to ensure the glove can be Stretched to facilitate insertion of the 15 wearer's hand into the glove with relative ease and without damage to the glove. Other important properties are minimising from barrier defects such as pin-holes.

The method of the invention may also be used to form other 20 elastomeric articles such as condoms and balloons.

COMPOSITION

The composition for producing an; elastomeric film suitably 25 comprises a dispersion or emulsion of an elastomer-forkiing polymer in a liquid. The composition generally comprises an elastomer-forming polymer and a cross-linking agent in a liquid medium. The liquid medium is typically water, although other solvents can be used. An emulsifier and 30 other optional components, as described in further detail below, may also be present in the composition.

The total solids content of the composition for forming the elastomeric film is between S% - 40% by weight of the 35 composition. The percentage of total solids content (TSC%) can vary within this range. The solids are diluted with liquid {such as water} to reach the desired

SSSSSSi.,·. (CeUMSIWraf PMUSALM JWWsJKLS concentration, Cienerally, fox* forming a thin or disposable type of glove, the total solids content will be towards the lower* end of this range ·· and within one of the following ranges: 2-30%, 4-30%, 4 -20%. 5-20%. For 5 forming thicker gloves, the total solids content will fee rid to be higher, or the glove will be produced from many more layers. Thus, for thicker gloves, the total solids content will tend to be within one of the following ranges: 4-40%, 5-40%, 5-30%, 5-20%, 10-40%, 10-30:%, 15-.10 40%, 15-30%. 2015203689 01 Μ 2015

Elastomer-forming polymers

Elastomer-forming polymers include natural rubber and Is synthetic elastomer-forming polymers, which can be cross-linked to produce elastomeric films, The polymer may fee a single polymer or a combination of two or more polymers. The polymer may be a homopolymer or a co-polymer. 20 The synthetic elastomer-forming polymer may be a polymer containing free ionically cross-linkable groups, covalently cross-linkable groups, or a combination of both. Examples of ionically cross-linkable groups are acids, including cax*boxylates, sulfonates and acid 25 anhydrides, and an example of a covalently cross-linkable group is a double bond.

Synthetic elastomer-forming polymers include copolymers produced by copolymerination of conjugated diene monomers 30 and ethylenically unsat Lira ted acid monomers {c a r fc oxy 1 a t e d polyacrylonitrile butadiene being an example of such a copolymer), polyisoprene, polychloroprene and/or polyurethane, Amongst the range of conjugated diene monomers, examples are 1,3-butadiene, iso-prene, 2,3-35 dimethyl-l,3-butadiene, 2-ethyl-1,ί-butadiene, 1,3- pentadiene, chloroprene and acrylonitrile. Regarding ethylenically unsaturated acid monomers, the acid group

PO0i4? AU 1 JACQU&S - 7 - 2015203689 01 Μ 2015 may be a carboxyl group, & sulfonic acid group or an acid anhydride group. Examples of ethylen.ical.ly unsaturated acid monomers include acrylic acid or methacrylic acid; itaconic acid,- maleic acid, fumaric acid, maleic 5 anhydride, citfaconic anhydride, sytrenesulfonic acid, monobutyl fumdrate, monobutyl maleate, mono-·2 - hydi'oxypropy 1 maleate, and.....alkali metal or ammonium salts thereof„ 10 One notable example of a synthetic elastomer-forming polymer is carfooxylated polyacryonitrile butadiene. This may be provided as a mixture of carfooxylated nitrile latex and nitrile butadiene rubber. 15 In the art of the present invention, it is common to refer to the amount of the elastomer-forming polymer as being........ 100 phr {per hundred parts "rubber"}, and for the relative amounts of the remaining components of a composition for producing an elastomeric film to be calculated as a number 20 of parts compared to the IGQphr of the elastomer-forming polymer, by weight, Thus, for an amount of cross-linking agent that is l/10Gth that of the elastomer-forming polymer in the composition by weight, the amount of cross-linking! agent is referred to as 1.0 phr. 2 5

It is also common in the art to use the expression "latex" or "rubber" to refer to any elastomer-forming polymer in a general sense. Accordingly, particularly In the examples which follow, it should be understood that these terms 30 have been used as short-hand to refer to the polymer of the dipping composition.

Cross-Linking Agents

Ss Elastomer-forming polymer's can be dross-linked with one or more cross-linking agents to produce the elastomeric film. Various types of cross-linking agents can be used. 2015203689 01 Μ 2015 10 15 carbamate;

Accelerators are: one sub-class of cross-linking agents which release sulphur, or act with sulphur-containing compounds, to accelerate sulphur-based covalent cross-linking of the elastomer-forming polymer. Generally, accelerators can be advantageous as they shorten the curing {vulcanisation) time, lower the curing temperature or decrease the amount of cross-linking agents required to be used in the composition. However, on the negative side, accelerators can give rise to allergic reactions, such as allergic contact dermatitis with symptoms including erythema., vesicles, papules, pruritus, blisters and/or crusting. Examples of accelerators include the ig, sine dibutyl dithiocarbaroate); thiurams {eg. tetraethylthiuram disulfide(1¾¾) and diphenylthiourea); thiazoles (eg zinc 2-mercaptobenzothiacole (ZMBT)),· guanidines (eg. diphenylguanidine) and aldehyde/amine-based accelerators (eg. hexamethylenetetramine). Other examples are well known in the art and can be obtained from various publicly available sources.

Another class of cross-linking agents are the ionic cross-linking agents, which include metal oxides and peroxides 25 (organic and inorganic). These work by ionically cross-linking ionically-crosslinkatale groups in the elastomerforming polymer. For example, when the elastomer-forming polymer is carboxylated polyacrylonitrile butadiene, a metal oxide cross-linker works by ionically cross-linking 30 the carboxylic acid groups. Examples of suitable metal oxide erbss-linking agents include the divalent metal oxide cross-linking agents, such as lead oxide, magnesium oxide, barium oxide, sine oxide and mixtures thereof, An example of a peroxide cross-linking agent is l,l-di{t-35 butylperoxy)-S,3(5-trimethylcyclohexane, which can be purchased under the trade name Trigonox 29-40B-pd. Combinations of these cross-linking agents can also be - 9 - 2015203689 01 Μ 2015 used, & further class of cross-linking agents are the covalent cross-linking agents, which include sulphur and sulphur-5 containing vulcanising agents. These, work by covalently cross-linking unsaturated double bonds present in the elastomer-forming polymer. The sulphur can be present in the form of elemental sulphur. The sulphur can also be donated by organic sulphuric compounds, for example TMTD 10 fTetramethylthiuram Disulfide). Sulphur donors such as this one are likely to contribute to chemical allergies and it is preferred to keep their use to a minimum in the manufacture of gloves when allergic content is an issue. Thus, if used, the sulphur is preferably present in the 15 form of elemental sulphur.

Generally, the amount of cross-linking determines the elasticity of the elastomeric film. Therefore, the amount and type of cross-linking agent will contribute to the 20 extent of cross-linking and the elasticity of the final elastomeric film.

For ic-nic cross-linking agents such as metal oxide and peroxide cross-linking agents, when used, the amount is 25 preferably in the range 0.2-8.0phr. The amount of metal oxide cross-linking agent is suitably within one of the following ranges; 0.2 ~ 5.0phr, 0.2 - 4.0phr, 0.2 -l.Sphr, 1.0 - 4.5phr, 0.5-1.5phr, 0,8-l.Sphr, G.8-1.2phr or 1.5 ~ 5,Ophr, 30

In some embodiments the composition for producing an elastomeric film is free of sulphur. In other embodiments, the cross-linking agent comprises sulphur. Sulfur requires high energy at curing (thus high curing 35 temperature and/or time) compared to other cross-linking agents. However, sulphur does provide the glove v;ith greater chemical resistance, and therefore it may be - 10 - 2015203689 01 Μ 2015 desired for this reason. The amount of sulphur in the composition may be in the range of 0 - 5. Ophr.. and when present, from 0.01 to 5.Ophr, 0.01 - 3,5phrf 0.01 - 3.Ophr 0.01 - 2,Ophr or 0,01 - l.Ophr or 0.01 - 0,5phr for 5 accelerator-free compositions. When the composition also includes accelerator, the amount of sulphur is suitably between 0.0 - 3.5phr, such as 0.01 - 3,Ophr, 0,01 ~ 2,Ophr, 0,01 - l,5phr, 0,01 - l.Ophr or 0.01 - 0,5phr. 10 According to one embodiment, the composition for producing the elastomeric film is accelerator-free.

According to another embodiment, the composition comprises an accelerator. When an accelerator is present, the 15 composition may be free of other cross·· 1 inking agents.

The amount of accelerator is suitably between 0,1 -2.Ophr, such as between 0.1 ~ l.Sphr, 0.1 - l.Ophr, 0.2-l.Ophr, 0.3 - 2. Ophr, 0.3 - 1.5ph.r or 0.2-0.6phr. 20 Preparation of the composition

The composition fox' producing an elastomeric film can be prepared by mixing the elastomer-forming polymer With a cross-linking agent, and optionally one or more additives, 25 in a liquid {eg, water),

Suitable additives that may be included in the composition can include one or more additives selected from the group consisting of stabilisers, emulsifiers, antioxidants, 30 vulcanising agents, polymerisation initiators, pigments, fillers, coloui'ising agents and sensitisers.

The preparation of the composition includes steps known in the art, and the composition can be prepared in a 3 5 conventic-nal manner. For example, the elastomer-forming polymer can foe diluted with a solution of a stabiliser·, such as potassium hydroxide, ammohium hydroxide and/or

(SHMatfciirsi P8BH2.AU.: JACCNJELS ~ 11 - 2015203689 01 Μ 2015 sodium hydroxide, fhe amount of stabiliser used is the pH of the can range dependent on the synthetic polymer employed, composition and other factors. The stabiliser 5 from 0.1 - 5.Ophr, e.g. 0.5 to 2phr, preferably 1.0¾ to I.Sphr, which is diluted with water, preferably filtered water.

A diluted stabilizer solution can be mixed with the elastomer-forming polymer, 'fhe pH of the mixture is 10 suitably adjusted to between 8.5 to 10.5, such as a pH between 9.0 to10.0. The cross-linking agent(s) can then be added to the mixture.

Antioxidants, for example Wingstal L (the product of p~ 15 25 cresol and dicyclopentadiene) may be added. The antioxidant may, for example, be added in an amount ringing from 1.1 - 5.Ophr, 0,1 - 3.Ophr, 0.1 - 1.Ophr or 0.3-0.Sphr. Pigments such as titanium dioxide, selected for its pigmentation, to reduce the transparency of the final elastomeric film, may be added in amounts ranging from 0.01 - 10.Ophr, such as 1.5-2.Ophr and colourants can

The mixture is then also be added in the desired amounts, diluted to the target total solids concentration within the range of 5% - 40% (or within any narrower range as described previously.) by the addition of a liquid, such as water.

Sensitisers are chemicals that can be used in compositions for producing elastomeric films to control the amount of 30 the composition that will remain coated on the mould during dipping. Examples of sensitisers known in the art that can be used in the composition for producing an elastomeric film include polyvinyl methylether, polypropylene glycol, ammonium nitrate and ammonium 35 chloride. #hen used, the amount of sensitiser will be chosen based on the desired film thickness to remain on the mould during dipping, and will generally be between

(GKfsfeiterS) PS0U5.AU. 1 JACClUSlS - 12 - 2015203689 01 Jul2015 0,0:1 - S . Ophr For thinner films, the amount will generally be between 0.01 to 2,Ophr, e,g. 0,1 to l.Ophr, When other techniques are used for controlling the film thickness on the mould, Such as the use of pre-dipping the 5 mould into coagulant before undertaking the multiple dipping into the composition for producing the elastomeric film, the composition for producing an elastomeric film may not comprise a sensitiser, 10 Production of Elastomeric Film

The manufacture of the elastomeric film may use conventional equipment, 15 Optional step (a) Dipping the mould into a coagulant containing multivalent ions in solution A suitable mould, which is based oxi the shape of the article to be produced (eg. flat for a film or glove- 20 shaped for a glove) can be dipped into a coagulant containing multivalent ions in solution. The dipping of the mbuld into a coagulant containing multivalent ions leaves on the surface of the mould a thin coating of the charged ions. The charged ions coating can assist in 25 controlling the amount composition for forming the elastomeric film that will subsequently remain on the surface of the mould after dipping into the composition, through charge interactions, 30 The multivalent ions may be cationic (as in the case of, for example, calcium ion-containing coagulants) or anionic, and the choice will be based on the identity of the elastomeric polymer. 35 Generally multivalent metal ion solutions containing multivalent cations are suited to a broad range of elastomeric polymers. Examples of such multivalent metal 13 2015203689 01 M2015 salt ions are calcium, magnesium, barium, ginc, ansi aluminium. The counterions may be halides (such as chloride), nitrate, acetate or sulphate, amongst others.

In the case of calcium ion»·containing coagulants, the 5 calcium ions can be provided as a solution of calcium nitrate or calcium chloride.

The coagulant may also include any other agents, such as wetting agents, anti-tack, agents and/or mould release 10 agents, such as silicon emulsions, polymer· release agents and metallic stearates, examples of which are sine and calcium stearates.

The concentration of multivalent ions can broadly be in 15 the range of 1.0 · 50% by weight of the coagulant solution (measured as the compound of the multivalent ion in the solution of the multivalent ions), depending on the desired thickness of the elastomeric film layers and the number of layers to be applied. In the case of thinner 20 layers, the concentration is suitably in the range of 1.0 - 20%, 1.0 - 15%, 1.0 - 12%, 1.5 - 20%, 1.5 - 15%, 1.0 -10%, 1,5 - 10%, 4 - 10%, 5 - 10%, 5 - 35%, 7 - 40%, 8 -50% and 5 - 45%. The amounts of other components such as wetness and anti-tack agents are dependent on the 25 properties desired through the use of these agents, and will vary accox'dingly.

The duration or dwell time for the mould in the coagulant is suitably between 1 and 30 seconds. In some 30 embodiments, the dwell time for the mould in the coagulant is 1 to 10 seconds. In some embodiments, the dwell time for the mould in the coagulant may be longer than 30 seconds. The temperature pf the coagulant into which the mould is dipped may, for example, he between 30°C - 80°C.

Prior to dipping the mould into the coagulant, the mould may be subjected to heating. The heating may form a part 14 2015203689 01 Jul2015 of a preliminary mould washing and drying procedure. The mould may in this case be heated to a surface temperature in the range of 2 5SC to 85*0, for example a: temperature in the range of 3 0°C to 704¾. 5

Optional step (b) Drying pr partially drying the coagu1 ant-dipped mou1d

If the mould is dipped into a coagulant, following this 10 step the mould is dried or partially dried.

Drying (or partial drying) is a step that may be repeated in several stages during the production of the multilayered elastomeric film Or article. At each drying or 15 partial drying step, the drying may foe performed toy any suitable technique or equipment known in the art, including the application of hot air or radiant heat, or a drying radiation source such as infra red (IR) and far IR radiation. This can be performed in an oven or any other 20 suitable drying equipment or environment. In the case of drying in an oven, or under the influence of hot air or radiant heat, the mould may be passed through the drying zone, which applies hiafe at an elevated temperature, for a period of time that is sufficient to drive off the excess 25 moisture/liquid to a sufficient degree of dryness. In the case of drying the coagulant remaining on the mould, the drying zone (such as oven) may for example be held at, or apply, heat at a temperature of between 50°C ~ 25Q°C. The mould typically remains in this zone (or progresses 30 through this zone) for a period of time sufficient to reach the target level of drying, and optionally a target surface temperature of the. coagulant on the mould, This may be between 25°C - S5°C, for example between 40°C - 70 |5 The surface temperature of a coating on the mould (in this case, the coagulant) can be tested by any suitable technique. One example involves the use of a device to measure the surface temperature of an object by the infra, red energy emitted by the object. An example of a device of this type is the Thermo-Hunter, model: PT-2LD produced by Optex Co. Ltd. Other techniques for measuring the 5 surface temperature of the.....film are known in the art. 2015203689 01 Μ

Step (i) Dipping the mould into a composition for producing an elastomeric film having a total solids content of between St - 40% to produce a layer of 10 elastomeric film compos1 tion on the mould

The mould is dipped into the composition fox' producing an elastomeric film, embodiments of which have been described in detail above,

IS

The mould is in the dipping tank for an amount of time to ensure the mould is evenly coated, but not so long as to develop a thicker coating than necessax'y. Depending on the required thickness of the coating, the dwell time of 20 the mould in the dipping tank may be between 1-30 seconds, such as between 2.0 to 7.0 seconds. 25

The temperature of the composition into which the mould is dipped is genex-ally within the range of 10*0 to SO^C, such as 10WC to 50°C, 15*C to 5Q°C, 20°C to 50°C, 25*0 to 50°C or 25°C to 45°C,

Preferably,, the surface temperature of the mould does not exceed the temperature of the composition for producing an 30 elastomeric film by more than S0°C, It has been found by the applicant that if the surface temperature of the mould is more than 80*0 higher than the temperature of the composition for producing an elastomeric film, shrinkage of the coating of elastomeric film composition on the 35 mould may occur. in some embodiments, the surface temperature of the mould is lower than the temperature of the composition for producing an elastomeric film, _ 1 £ „ 2015203689 01 Μ 2015

Δ W

However,· typically, the surface temperatures of the mould is about 2 0*C to 60°C higher than the temperature of the composition lor producing an elastomeric film. 5 Step :{ii) Partially drying the layer of elastomeric film composition on the mould

The coating or layer of elastomeric film composition on the mould is then partially dried, as opposed to fully 10 dried, to reduce the water content but without the water content lowering to such an extent that it falls below 22%, The partially dried elastomeric film composition has a water content in excess of 22% by weight which reflects that some moisture remains in the elastomeric film 15 composition layer on the mould. Typically, the elastomeric film composition on the mould is dried to a moisture content between 22% and 80%, for example, to 25% to 75% or 30% to 77% or 25% to 60%. 20 If the elastomeric film composition on the mould is dried to a water content of less than about 22%, the layer of the elastomeric film on the mould appears visibly dry and when dipped in a composition for forming an elastomeric film having d total solids content of between 5 to 40%, 25 tie composition does not readily adhere to the surface of the dried layer of elastomeric film composition on the mould. A flow mark also becomes visible, and the final product displays shrinkage and/or weak spots. The coating may also be uneven.

SO

The partial drying may be conducted using the same type of drying technique as described above in relation to step {b.S, using conditions necessary to reach a state of partial dryness, 35

The partial drying may be performed by any suitable technique or equipment known in the aft, including the " ,11 - 2015203689 01 Jul2015 application of hot air or radiant heat, or a drying radiation source such as infra red (IR) and far IR radiation. This can he performed in an oven or any other suitable drying equipment or environment, 5

In the case of partial drying in an oven, or under the influence of hot air or radiant heat, the mould bearing the layer or coating of elastomeric film composition may be passed through the drying zone, which applies heat at 10 an elevated temperature, for a period of time that is sufficient to drive off some of the excess moisture/liquid to a sufficient degree of partial dryness. In this case, the drying zone {such as oven) may be held at, or apply, heat at a temperature of between 50°C - 30Q°C {depending on 15 the drying time), This time period may be between 2 - 300 seconds (depending on the temperature of the oven). Generally, the higher the oven temperature, the shorter the time period in the drying zone, and vice versa. 20 Generally, during the partial drying, the mould remains in the drying zone {or progresses through this zone) for a period of time sufficient to raise the surface temperature of the layer of elastomeric film composition on the mould to a maximum temperature between, 25°C and S5°C, e.g. 40°C 25 to 80°C. If a higher surface temperature is reached, excessive or uneven drying may occur. In addition, the elastomeric film composition on the mould may require cooling prior to the next dipping step. An additional cooling step may result in delays or additional costs in 30 the manufacture of the elastomeric film or article.

The surface temperature of the elastomeric film composition on the mould can be measured using the same techniques described above with respect to the coagulant 35 layer surface temperature.

The partial drying is required to reduce the water content

S6SS2*3U £GHMe«s«) AU t JACQUCU - 18 - 2015203689 01 Μ 2015 of the elastomeric film composition on the mould. The water content of the partially dried elastomeric film composition is greater than 22%. The water content of the elastomeric film composition on the mould can be 5 determined by measuring the mass of a sample product at the point of completion of the partial drying step, and then driving off the remaining moisture/liquid in the sample product to obta.in the dry mass of the product, and determining from these two values the total water content. 10 Thus, if the single-layered product at this point in time weighs 100 mg, and the dried product weighs 90 mg, the water content is 10%.

Following from this procedure, in some embodiments, the 15 method may comprise the steps of: - measuring the mass of a sample glove product at the point of completion of the partial drying step {ii}, - driving off the remaining moisture in the sample glove product to obtain the dry mass of the product, 20 and - determining from the two values the water content of the sample glove product following the partial drying step. 25 Further, as explained in further detail in the example section below, the method may further comprise controlling the partial drying step to maintain the total water content within a precondition range for the elastomeric film composition following partial drying, based on the 30 sample glove product results.

Step (iii) Dipping the mould coated with the partially dried layer of elastomer'ic film composition into a composition for producing an elastomeric film having a 35 total solids content of between Sf - 40% to produce a further layer of elastomeric film composition on the·· mould 19 2015203689 01 Μ 2015

The mould coated with the partially dried layer of elastomeric film composition is dipped into a composition for producing an elastomeric film. The composition into which the mould is dipped can be the same as or different to the composition used to form the first layer. The composition may differ with respect to the identity and/or amount of the elastomer-forming polymer, the identity and/or amount of any cross-linking agent, the identity and/or amount of ether additives, and the total solids 10 15 content. In some embodiments, the identity of the elastomer· forming polymer in the second composition is the same as that used in the first composition. In such embodiments, the amount of the cross-linking agent is also typically the same. in other embodiments, the identity of the elastomer-forming polymer of the second composition is different, to that in the first composition. The total solids content of the second composition may be the same or different to that of the first comoosition. The total solids content will depend in part on the desired thickness of the second (or further) layer being applied.

The dwell time of the mould in the second composition is, for example, between 1 and 30 seconds, such as 1 and 20 seconds, 1 and 10 seconds, such as 2 to 5 seconds. 25

The temperature of the composition into which the mould is dipped is generally within the range of lO^C to SQ^C, such as 10eC to 50°C, 15°C to 50°C, 20°C to 50°C, 25cC to 50°C or 25°C to 45°C. 30

Preferably, the surface temperature of the partially dried layer of elastomeric film composition on the mould does not exceed the tempex-ature of the composition for forming an elastomerid film by more than about 80°C. It has been 35 found by the applicant that if the surface temperature is more than about 80c€ higher than the temperature of the composition for forming an elastomeric film, shrinkage of eesaasa./ the elastomeric film composition on the mould may occur, in. some embodiments, the surface temperature is lower than the temperature of the composition for forming an elastomeric film. However, typically, the surface 5 temperature is about 20*0 to 60°C higher than the 2015203689 01 M2015 temperature of the composition for forming an elastomeric film.

Step (iv) Optionally repeating the partial drying step 10 (ii) and the further dipping step (Hi)

The partial drying step and further dipping steps may be repeated. These steps are suitably repeated at least once, and may be repeated multiple times. For each 15 repeated step, the conditions may be different compared to the original partial drying conditions and dipping conditions for producing the second layer. Thus, as an example, extent of partial drying, the total solids content of the composition for forming an elastomeric film 20 may differ for each layer.

For each partial drying step, the layer of elastomeric film composition in the mould is partially dried to reduce the water content of the elastomeric film composition such 25 that water content of the partially dried layer of elastomeric film on the mould has a water content of greater than 22%. This water content is measured by reference to the water content of the entire elastomeric film layer on the mould (chat is, the elastomeric film 30 layer formed by multiple dipping).

The average thickness of each layer is typically between 6% and 90% of the final elastomeric film, with some layers {such as the first layer) suitably being between 30 to 35 70%, or 40 to 65% of the full film thickness. The average thickness of each layer is dependent on the number of layers of composition forming the final elastomeric film. 21 2015203689 01 Μ 2015

The final elastomeric film can, for example, consist of 2 to 15 layers, such as 2 to 10 layers, 2 to 6 layers, or 3 to 6 layers. 10

Generally, although not always, the greater the number of layers in the film; the lower the % TSC of the composition for producing each subsequent layer. This is to keep the thickness of the multilayer film to a minimum. After the first layer, the % TSC of the composition used to produce each subsequent layer may be in the range 5% - 40% TSC, such as 5-30% or 5-12% or 10-30%¾ or 10-40% or 10-20%,

Each layer can be of approximately equal thickness, or of differing thickness. For example the 1st layer can be 50 15 %, 2nd layer 30%, 3rd layer 20 % for a 3-layer film,

Approximately equal thickness can be achieved by varying the total solids content of the composition of each layer and the temperature at which the layer is deposited. Different mechanisms of deposition can occur for each 20 layer and different thicknesses can be deposited even if the % TSC is maintained at the same level. Accordingly, varying the % TSC is sometimes required to maintain the same level of thickness, The thickness of the deposited layers can also vary according to the concexxtration of 25 multivalent ions in the coagulant solution, or the amount of any sensitiser present in the composition for producing the elastomeric film temperature of the composition, and dwelling time of the mould into the composition, 30 Optional additional steps prior to drying and curing

Further steps can be taken to fine-tune the manufacture of the elastomeric film or article, The film or article can be leached to remove extractable components. Suitable 35 conditions for leaching extractable components from the film or article can involve contacting the film or article with heated water (eg, through immersion) at a temperature

3S&32S3J tC-HMaiters) PS&K2.AU.! JAC-3UBLS - 22 - 2015203689 01 Μ 2015 between 4 0 to 5ϋ°0 for between 1 to SO mins. During this leaching process, a substantial amount of soluble and extractable components {such as surfactant, ionic compounds) can be removed.

In the case of glove manufacture, the glove can be subjected to beading/cuffing to create a bead or cuff at the wrist end, of the glove, 10 Step f'vj Drying and/or curing the layered elastomeric film on the mould

The film or article is then dried and/or cured. In some embodiments, the step {v) comprises drying and curing the 15 layers of elastomeric film composition on the mould.

This step can be effected in an oven with a minimum temperature of 80*C, in the range 8G-15G°C, or a minimum temperature of 90°C (such as 90-150°C} at a minimum time of 20 10 minutes, in the range 10-4Qmins. Other drying and curing techniques that can be used ludes UV curing.

Optional additional steps following drying and/or curing 25 The film or article can be subjected to one or more further process steps prior to stripping of the film or article from the mould. These optional steps include cooling, chlorination, post-curing rinsing, polymer coating and additional drying steps. 30

The film or article is stripped from the mould at the conclusion of the formation process.

Elastomeric film features 35

The thickness of the final film (or article) can, for example, be in the range 0.01-3.0mm, such as 0.01-0.3mm,

CP80M2 AU t JAC-aUEtS 0,02-δ. 2mmf 0 . QS-0.10mm, 0.03-0.08mm, or 0.05·· 0 . 08 mm (for thin or disposable gloves) ,. and 0.2 - 3.0mm for thick gloves. The thickness is suitably measured as an "average thickness", particularly for gloves, using the points of measurement described below. 2015203689 01 Μ 2015

The film properties can be measured according to ASTM D-412, In one embodiment in which the thickness (average thickness) of the film is measured at 0.03-0.10mm, the 10 physical features of the film are suitably; minimum tensile strength of 10.0 Mpa, relatively low in modulus at 300% of less than 10.0 Mpa and minimum elongation of 500%, Ift another embodiment in which the thickness (average thickness) of the film is measured at 0.03 0.10mm, the 15 physical features of the film are suitably minimum tensile strength of 14.0 Mpa, relatively low in modulus at 300% of less than 5,0 Mpa and minimum elongation of 500%,

The desired durability of the film is determined by the 2 0 end use of the article. For example, for gloves for non·· surgical use, the wearing time is usually below 3hrs, and commonly less than 2hrs, The durability of the film can be controlled by the curing conditions. Generally, the higher the curing temperature, the more durable the elastomeric 25 film,

The term "average thickness" in respect of the thickness of a glove (specifically the multi-layer elastomeric film forming the glove) refers to the average of three 30 thickness measurements, taken at points along the layer of the elastomeric film. The measurements are taken at the cuff, the palm and the finger tip. When measuring the thickness of individual layers of the glove, the "average thickness" is a reference to the average thickness of that 35 layer of film, taken at the three measurement points.

This may be measured in absolute terms (in mm), or as a percentage of the full thickness of the multi-layered

83S3253J (OMMaKerej Αϋ.ΐ JACSUEi.S >Λ - 2015203689 01 Jul2015 glove. For elastomeric articles, a similar technique using three thickness measurements can be used to determine the "average thickness".

The method described above can be used to produce a multilayered elastomeric film or article with reduced 10 potential for defects such as pin holes, weak spots and/or delamination compared to prior art processes for producing multilayered elastomeric films in which each layer is fully dried prior to applying a subsequent layer.

Further, the method can be used to produce stronger multilayered elastomeric films than some prior art processes.

For thin gloves, of the type used for disposable applications, the method can be carried out using a filmforming composition having a very low concentration of solids, and other factors, which assist to keep each coating layer thin. Accordingly, the overall thickness is kept to a minimum. At the same time, the partial drying step performed between the application of each layer of film-forming composition aids to ensure good lamination, or adhesion and coverage, between adjacent layers.

Without this step, difficulties are faced in trying to obtain a multi-layer film having the desired properties. 25 In the claims and in the preceding description, except, where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify thd presence of the 30 stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

EXAMPLES 35

The invention will now be described in further detail with reference to the following non-limiting examples. All

«βΜΜΜΜ» PMM&AU I JACaUBLS 25 2015203689 01 M2015 tables of compositions and test results are shown in the Tables section. All testing procedures are shown in the Testing Procedures section.

5 GENERAL PROCEDURES 10

In the examples set out below, the following general procedure was utilised to produce elastomeric films, and gloves in particular. The general procedure was also used to demonstrate the impact (if any) that certain processing conditions and components of the elastomeric film forming compositions have on the quality of multilayer elastomeric films produced. 15 General Procedure 1» 1.1 Washing

The mould is subjected to pre-washing, so as to be clean of any remaining residues following removal of 20 a glove made on the mould previously. The mould is then dried in an oven at 7C-°C, reaching a surface temperature of around 60°C (50°C - 63°C} , 1.2 Coagulant Dipping 25 fhe mould is dipped in the coagulant in accordance with the following parameters;

Operating Parameter Tank Temperature 1 (°C) I Dwell Time {second) Ca{N03)2 (% in water) pH Coagulant Dipping Tank See example details -generally 53 ~ 62°C 1 2 See example details See example details N 1,3 Oven Drying 30 The mould is dried in accordance with the following 26 - parameters:

Oven Operating Parameter Temperature (°C) Time (second) Coagulant Oven Blower 135 I 38 2015203689 01 Μ 2015 1.4 Pre-condition 1 1.'

.κ:> AW 20

The oven drying as described in step 1.3 is used to obtain certain "preconditions" for the coating on the mould, prior to proceeding to the next step. Precondition I refers to the conditions of surface temperature and "dryness" of the mould coated with coagulant achieved following oven drying, prior to continuing to the next step. In some examples, precondition 1 is manipulated to demonstrate the impact that pre-condition 1 has on the final product. Where the pre-condition is not specified, it is as set but below;

Operating Parameter Pre-condition 1 Surface temperature of mould Mould Condition of the mould ( Dryness : Wet / coated with \°C) Partially Dry / Dried) Ca2 "prior to See example details - See example details - 59°C if not Partial Dry / Dried if dloping specified not specified 1,5 First stage dipping

The mould following:; step 1.4 is dipped into a tank of compositidh for forming an elastomeric film, containing the components specified for the given example, The Gdhdibfdns in the first stage dipping step are as follows: - 2"

Operating Parameter Tank Temperature (°€) Dwell Time (second) TSC pH First stage See example details. 4 0 ·· 4 2 if Sei example details - 4 seconds if See i See dipping not not example..... example tank specified specified details [ details 2015203689 01 Μ 2015 1.6 partial drying

Unless otherwise specified to test the impact of the degree of dry!ng on the final product., the dipped S mould is passed through an oven held at the temperature for the time indicated below. In some examples, the degree of drying following the first stage dipping is modified from this parameter to demonstrate the impact that a different degree of 10 drying has on the final product. - 28 -

Oven Operating Parameter Temperature i°C) Time (second) Gelling Oven 1 120 unless otherwise specified. 12 unless otherwise specified. 2015203689 01 M2015 1.7 Pre-condition 2

The partial drying as described in step 1.6 is used S to obtain certain "preconditions" for the layer coated onto the mould, prior to proceeding to the next step. Pre-condition 2 refers to the conditions of surface temperature and "dryness" of the mould coated with the first layer of composition for &0 forming an elastomeric film achieved following {partial} drying, prior to continuing to the next step. In some examples, pre-condition 2 is manipulated to demonstrate the impetct that precondition 2 has on the final product. Where specific 15 conditions for pre-condition 2 are not specified, the conditions are as set out below:

Pre- Operating Parameter condition 2 Surface Temperature of mould (°C) Mould Condition {Dryness : Wet. / Partially Dry / Dried) Water Content (%) Around 40 - Partially As specified - 44*C, Dried unless generally 85% - unless otherwise 22% unless otherwise specified specified different conditions tested, Most typically around 5 0 % ·· 70i. 1.8 Second stage dipping 20 The mould following step 1.7 is dipped into a tank of

585SiS3.'. [SKWilM'SS MetiUSLS - 2$ - 2015203689 01 Μ 2015 composition for forming an elastomeric film, containing the components specified for the given example. The conditions in the second stage dipping step are as follows;

Tank Operating Parameter Temperature (°C) Dwell Time (second) TSC (%) pH Second stage dipping tank See example details. 40 - 42 if not specified See example details -4 s. if not specified See example details See example details 1,9 Partial drying

Unless otherwise specified to test the impact of the degree of drying on the final product, the dipped 10 mould is passed through an oven held at the indicated temperature for the time indicated below. In some examples, the degree of drying following the second stage dipping is modified from this parameter to demonstrate the impact that a different degree of 15 drying has on the final product.

Oven Operating Parameter Temperature (°C) Time (second) Gelling Oven 2 90 - 110 unless otherwise specified 12 unless otherwise specified 1.10 Pre-condition 3

The partial drying as described in step 1.9 is used 20 to obtain certain "pre-conditions" for the layer coated onto the mould, prior to proceeding to the next step. Pre-condition 3 refers to the conditions of surface temperature and "dryness" of the combination of layers coated on the mould achieved 2015203689 01 Μ 2015 - 30 ~ following (partial) drying, prior to continuing to the next step. In some examples, pre-condition 3 is manipulated1 to demonstrate the impact that precondition 3 has on the final product. Where specific 5 conditions for pre-condition 3 are not specified, the conditions are as set out below:

Pre-condi t ion Operating Parameter 3 Temperature Surface Of mould (°C) Mould Condition (Dryness : Wet/ Partially Dry/ Dried) Water Content (!) of the mould About 41, Partially As specified unless Dried, unless - generally 1st and 2nd otherwise otherwise 85% - 22% dipping compos i t ions specified specified unless different conditions tested. Most typically around 50% -70% . 1.11 Third stage dipping 10 The mould following step 1.10 is dipped into a tank of composition for forming an elastomeric film, containing the components specified for the given example. The conditions in the third stage dipping step are as follows:

Tank Operating Parameter Temperature (°C) Dwell Time (second) TSC (%} PH Dipping Tank 3 See example details . About 3 0 (29 - 34) if not specified See example details. About 4 if not specified See example details See example details 31 2015203689 01Jul2015 1.12 Beading

The product following third stage dipping is subjected to beading. 5 1.13 Drying

The product following third stage dipping, and beading;, is oven dried at a temperature between 80°C and 120°C for around SO seconds.

Xo 1,14 Pre-cure leaching

Pre-leaching is conducted by rinsing in warm water for a short period of time.

The beading, drying and pre-cure leaching steps could 15 be carried out in any order. The processes of beading and pre-cure leaching could be exchange depending on the quality of cuff beading. 1.15 Curing 20 Oven curing is conducted through ovens having 4 zones set at successive temperatures of 118, 105, 135 and 108°C, taking approximately 4-6 minutes to progress through each zone. 25 1.16 Post curing steps

The product is water cooled, chlorinated in a 745ppm chorine solution at pH 2,0 held at 52°C for 50 seconds, neutralized and rinsed in water, dried and stripped from the mould. 30 ISt&MPLE 1

Cloves were produced using: Procedure 2, which is within the framework of General Procedux'e 1, from Glove 35 Composition 1 outlined in Table 1. It is noted that some parameters varied a little between individual samples, and where this occurred this is indicated by a range that

8S5K53J 32 2015203689 01 Μ 2015 coders the variations .

The gloves produced were of good quality, with good adhesion between the layers of elastomeric film, good 5 pick-up of latex composition, no latex flow mark, no rlibber lump formation, no thin or weak spots, no pin-holes and no shrinkage, The gloves were found to have an average durability time of 4 hours {4.012 hours) when subjected to the durability test over 50 samples, 10

Procedure 2 : 1.1 Washing as described in General Procedure 1. IS 1.2 Coagulant dipping in accordance with the following parameters,

Tank Operating Parameter Temperature (°C) Dwell Time (second) Ca {NO3} 2 {% in water) pH Coagulant Dipping Taxxk 53-57 2 10,1 - 10.s 7.2- 7,5 1.3 Oven drying in accordance with the following 201 parameters;

Oven Operating Parameter Temperature (°C) Time (second) Coagulant Oven Blower 135 38 asssassj »?<.·> 4?,AU.: 2015203689 01 Μ 2015 - 33 1.4 Pre-condition 1 parameters: Operating Parameter Pre-condition 1 Surface temperature of mould Mould Condition i Of* \ \ w ( Dryness : Wet / Partially Dry / Dried) 53 Partial Dry / Dried 1-5 First stage dipping parameters: 5 i Operating Parameter Tank Temperature (°C) Dwell Time (second) TSC I pH (%) 1 Dipping [ Tank 1 Target 40 {between 40 -- 4 2) 4 Target ] 17.0 | Target (16.8 | 9.2 | ¢9.0 -17.4) | 9.3) 1,6 Partial drying parameters as described in General Procedure 1 (120°C for 12 seconds). 10 1,7 Pre-condition 2 parameters:

2015203689 01 Μ 2015 - 34 - 1,8 Second stage dipping parameters:

1.3 Partial drying parameters as described in General 5s Procedure 1 (90 ~ 110°C for 12 seconds). 1.10 Pre-condition 3 parameters:

10 1.11 Third stage dipping parameters:

Tank Operating Parame ter Temperature t °c) Dwell Time (second) TSC {%} pH Dipping Tank 3 Target 30{2S - 34) 4 18.2 όν-Ο.!) 9.2 { + /“ : 0.1) 1.12 - 1.16 Steps were performed as outlined in General Procedure 1, 15 EXAMPLE 2

This example demonstrates multilayer gloves can he made when using different process conditions and a different 2015203689 01 Μ 2015 - 35 - composition to that used in Example 1 above. Gloves were produced usings Procedure 3, wlich is within the framework of General Procedure l, from Glove Composition 2 outlined in Table 2, It is noted that some parameters varied a 5 little between individual samples, and Where this occurred is indicated by the range that covers the variations.

The gloves produced were of good quality, with good adhesion between the layers of elastomeric film, good 10 pick-up of latex composition, no latex flow mark, no rubber lump formation, no this or weak spots, no pin-holes and no shrinkage. The gloves were found to have an average durability time of 3 hours 53 minutes {3,875 hours) when subjected to the durability test over 50 15 samples.

Procedure 3: 1.1 Washing as described in General Procedure 1, 20 1.2 Coagulant dipping m accordance with the following parameters, It is noted that the calcium concentration is lower and the pH higher than for Procedure 2 In order to form a thinner film.

Is

Tank Operating Parameter Temperature (°c> Dwell Time (second) Ca(N03) a {% in water) PH Coagulant Dipping Tank 56 2 6,3 8.7 2015203689 01 Μ 2015 - 36 - 1.3 Oven drying in accordance with the following parameters:

5s 1-4 Pre-condition 1 parameters:

Operating Parameter Pre-condition 1 Surface temperature of mould Mould Condition C°C} ( Dryness : Wet / Partially Dry / Dried) “ Γ» Partial Dry / Dried 1.5 First stage dipping parameters:

Tank Operating Parameter' Temperature i°C) Dwell Time (second) TSC (%) pH Dipping Tank 1 40 4 14.3 9.6 1,β Partial drying parameters as described in General Procedure 1 {12Q°C for 12 seconds). 1.7 Pre-condition 2 parameters:

Pre~ Operating Parameter condition 2 Surface Mould Condition Temperature (Dryness : Wet Water of mould / Partially Dry Content (%) i°cf / Dried) 40 Partially Dried 73.98 2015203689 01 Μ 2015 ~ 37, - 1.:8 Second stage dipping parameters. It is noted the total solids content is lower than that used in Procedure 2.

1.9 Partial drying parameters as described in General Procedure 1 {90 · 11Q-C for 12 seconds) , 1.10 Pre-condition 3 parameters: P re-eondi t ion 3 Temperature Surface Of mould (°C) Mould Condition (Dryness : Set / Partially Dry / Dried} Water Content (%) 41 j Partially | Dried 65.64 1.11 Third stage dipping parameters. It is noted that the TSC is lower than that used in Example 1.

1.12 - 1.16 Steps were performed as outlined in General Procedure i.

{SHWMicrsi JACOUSi-S

3 S 2015203689 01 Μ 2015 EXAMPLE 3

Examples 3 demonstrates that multilayer gloves can fee made when using a range of different process conditions within 5 the invention and a range of different glove compositions. The glove compositions tested in Example 3 are those of Glove Composition 3 outlined in the combination of Tables 3 and 4. The compositions tested in this Example contain varying amounts of metal oxide crosslinking agent (MgO was 10 the test metal oxide), or non-metal oxide {TETD was the test agent), combined with varying concentrations of coagulant solution and varying total solids contents of the latex composition. The various combinations of variants produced 43 different glove samples. The 15 compositions in this example were accelerator-free.

The process used to produce the gloves was General Procedure 1,, in which the parameters were controlled as outlined in the Table 6. The combinations of cross-20 linking agent, concentration of coagulant solution, the total solids content of the composition for forming an elastomeric film and dwell time used are shown in Table 6. The thickness of the various layers formed was measured for some of the multi-layered elastomeric gloves produced, 25 The extent of barrier defects, durability, stickiness and evenness of coating for the multi-layered elastomeric gloves produced were assessed as described in the Testing Technique section at the end of the Examples, The results are shown in Table 6, 30

The

Gloves were also produced from the Glove Composition 4 outlined in Table 5 which contains 1,50 phr of SnO and 0.20phr of sulphur as crosslinking agent, 0.2 phr of antioxidant, and no accelerator. The procedure was as 35 described for the production of gloves in Example 3.

jAfrayfilS ., " 39 2015203689 01 M2015 gloves produced from the accelerator-free compositions were of good quality. 5

Example 4 was conducted to confirm and demonstrate the finding that improved glove quality can be achieved by only partially drying each layer of composition prior to applying the next layer of composition for forming the 10 elastomeric film, The test results also determined and demonstrate a range of favourable conditions of water contents and surface temperatures for easy coating.

This example was conducted in two parts. In both parts of IS Example 4, Glove Composition 1 was utilised as the test composition,

Other tests were conducted (results not reported), on corresponding compositions containing between 0,2 to 4.0 20 phr of MgG, BaO, Ai2o3i peroxide and DPC4 as the cross-linking agents. The results confirmed that the partial drying principle applies equally to compositions containing these cross-linking agents. 25 In the first part, the temperature of the drying oven was kept at a constant 12 0£5CJ and the time that the mould coated with the first layer of composition was in the oven prior to the dipping in a second layer of composition was adjusted from 0 seconds up to 1000 seconds. For the 30 samples dried for a time of 240 seconds or less, the glove was subjected to a second stage of partial drying followed by a third dipping to produce a third layer of composition. The third stage dipping was not performed fqr samples dried for more than 240 seconds, as the 2-35 layer products were already showingsigns of poor quality, This test revealed the impact that, greater drying times have on the surface temperature of the coating on the

liiNMaMrH J*eQUEi.S 2015203689 01 Μ 2015 mould, on the water content of the layer, and then on the product quality of the glove produced, 5

The first part of Example 4 was conducted, in accordance with General Procedure 1, With the following parameters: Step 1.2 Coagulant dipping at 60*C (58 to gH°C} , pH 7.6, 10 8.7% Ca (] Step 1 .3 Step 1 .4 7 Q*C) Step 1 . 5

Step 1.4 Surface temperature of about 59°C (between S3 to 15 20 25

Step 1.5 Dipping in Glove Composition 1 at 16.7% total solids concentration, pH 9.7, 29*C for 5 seconds Step 1.6 Partial drying at 12 0^0 for the time period. indicated in the first column of Table 7 Step 1.7 Pre-condition 2 as indicated in Table 7 Step 1.8 Dipping in Glove Composition 1 at 16.7% total solids concentration, pH 9.7, 29s€ for 5 seconds Steps 1,9-1,if conducted for samples dried in drying oven 1 for up to 240 seconds, but not conducted for samples dried for more than 24G seconds previously (2 layers only); corresponding water contents calculated at the end of the procedure. Step 1.9 Partial drying 2 conducted at 120°C for the tiite period indicated in Table 7 (0 to 240 seconds) Step 1.10 Pre-condition 3 as indicated in Table 7. Step 1.11 Dipping in Glove Composition 1 at 16.7% total solids concentration, pH 9.7, 23*C for 5 seconds. Steps 1.12 - 1,16 as described in General Procedure 1, 30 The results of Example 4 part 1 are shown in Table 7. In the second part., the temperature of the drying oven following first stage dipping was kept at a constant 120°C, but this time the first-layer coated mould was held in the 3:5 oven for a time of between 24 0 seconds and 1000 seconds as indicated in Table 8, followed by cooling to reduce the surface temperature to 40°C. The heating and cooling was - 41 a- 2015203689 01 Μ 2015 foilowed by the second stage dipping. This test explored whether the important factor to control inthe process was the surface temperature of the layer of film prior to dipping a subsequent layer, or the water content. 5

The second part of Example 4 was conducted in accordance with General Procedure 1, with the following parameters: Step 1.2 Coagulant dipping at 60*C (58 to 62°C), pH 7,6, 8.6% ciiHOj) 2-

10 Step 1,3 Oven set at 120°C

Step 1,4 Surface temperature of about 59°G {between 56 to 7 0°C)

Step 1.5 Dipping in Glove Composition 1 at 17% total solids concentration, pH 9,7, 25°C for 5 seconds 15 Step 1,6 Partial drying at lf0°C for a time period between 240 seconds and 1000 seconds, as indicated in Table 8 Step 1,7 Allowing the surface to cool to about 40°C, before progressing to step 1,8; corresponding water content calculated at the end of the procedure. 20 Step 1,8 Dipping in Glove Composition 1 at 17% total solids concentration, pH 9.7, 25°C for 5 seconds Steps 1,9-1,11 not conducted (2 layers only)

Steps 1,12 - 1.16 as described in General Procedure 1, 25 The results of Example 4 part 2 are shown in Table 8.

The combination of the test results for parts 1 and 2 of Example 4 show that the important factor to control is the water content, and that partial drying should not be 30 progressed to an extent such that the water content of the layers of composition falls below 22%, Below this water content level the glove quality drops off, with a poor pick-up of the composition {poor adhesion between the layers) and an increase in shrinkage,

«WWtt.I JACOUELS 42 2015203689 01 Μ 2015 EXAMBLE 5

Example 5 was conducted to confirm and demonstrate the finding that improved glove quality can be achieved by B only partially drying each layer of composition prior to applying the next layer of composition for forming the elastomeric film,

In Example 5, the impact of different levels of drying 10 before each layer is coated onto the mould was tested. In part A, the impact of different drying levels of the coagulant before the first layer was dipped was tested, in part B the impact of different drying levels of the first layer before the second layer was dipped was tested, and 15 in part C, the impact of the different drying levels of the second layer before the third layer was dipped was tested. In all other respects, the process conditions wei'e kept uniform. 20 The tests were conducted using Glove Composition 1, and General Procedure 1, with the process parameters controlled as outlined in Tables 9A, 9B and 90, and as follows; 25 Step 1.2 Goagulant dipping at 6G°C {58 to 61°C} , 9.3%

Ca {N03} 2 , pH 7.8.

Step 1,3 For part 9Ά, the oven temperature was set to a suitable level, and the time in the oven controlled, to get to a surface temperature in the target range for 30 testing, the target range being set out in the left hand column of Table 9Ά, In sorte cases no drying in the oven was required - instead the layers were allowed to cool in ambient conditions. For parts 9B and 9C, the oven was set to 120°C. 35 Step 1.4 For part 3Ά, the surface temperature was as identified in Table 9A. For parts 9B and BC, the surface temperature was around 59°C (between 59°C and 81*0

<ahM$t*ers; : JACCUELS 2015203689 01 Μ 2015 10 15 25

Step X.5 Dipping in Glove Composition 1 at 17.5% lotal solids concentration^ pH 9.7, 29WC for 5 seconds Step 1.6 For part 9Ά, the oven was set to 12Q°€ and observations were made on the coating quality and recorded under "Observations after lsc dip layer". The testing ended for part 9Ά here. For part 93, the ovett temperature was set to the necessary level to achieve a surface timperature for the first layer on the mould to be within the target range for testing. The target range is set out in the left hand column of Table SB, For part 9C, the oven was set to 120°C for partial drying.

Step 1,7 The surface temperature for Pre-condition 2 for part 9B is indicated in Table 9B. The surface temperature for part SC was between 45°C and 52°C.

Step 1.S Dipping in Glove Composition l at 17.5% total solids concentration, pH 9.7, 29°C for 5 seconds for parts 9B and 9C,

Step 1.9 The oven temperature for part 9B was set to 120^0 and observations were made on the coating quality and recorded under "Observations after 2rid dip layer" in Table 9B. The testing ended for part 9H here. The degree of drying for part 9C was controlled to attempt to reach the desired surface temperature range indicated in the left hand column of Table 9C. The oven temperature was set to a suitable level, and the time in the oven controlled, to get to a surface temperature in this range. In some cases no drying in the oven was required - instead the layers were allowed to cool in ambient conditions.

Step 1.10 The surface temperature for Pre-condition 3 for part SC is indicated in Table 9C.

Step l.ll Dipping in Glove Composition 1 at 17.5% total solids concentration, pH 9.7, 29°C for 5 seconds for part

Step 1.12 The product from step 1.11 was dried in an oven 35 at 12C*C, while observations were made and recorded under "Observations on 3rd dip layer" in Table 90. 44 - 2015203689 01Jul2015

In this example, the:: drying conditions were varied to determine and demonstrate the properties of films/gloves 5 produced with a different extent of drying of the layers of elastomeric film on the mould prior to application of a further layer of elastomeric film.

Changes were made to the surface temperature of the mould prior to the first dipping in the composition for forming an elastomeric film {pre-condition 1) and to the water 10 content and surface temperature of the layers of elastomeric film on the mould prior to the second and third dipping in the composition for forming an elastomeric film (pre-conditions 2 and 3). 15 Total water content, latex pick up, flow marks, lumping, weak spots, pin holes and shrinkage of the layers after dipping were assessed.

The results of the assessment are set out in Tables 9A to 20 9C, Table 9A sets out the results of the experiment conducted to examine the effect of changes to precondition 1 on the formation of the first layer of elastomeric film. Table 3B sets out the results of the experiment conducted to examine the effect of changes to 2S pre-condition 2 on the formation of the second layer of elastomeric film. Table 9C sets out the results of the experiment conducted to examine the effect of changes to pre-condition 3 on the formation of the third layer of elastomeric film. It is noted that the procedure used to 30 determine the water content of a particular product results in destruction of the product, and therefore separate trials were required to build up the water content results for each layer, giving the set of tables A, 13 and 0. 35

In these tables, “dried" refers to a water content of between 1 - 22%, and “partially dried" refers to a water

JACQlXSLS 2015203689 01 Μ 2015 conten

35

The results show that the water content, of the films following drying {specifically, partial drying) is 5 critical to the properties of the film/glove produced.

The results also show that the surface temperature is not critical for easy/good coating, provided that the: necessary water content corresponding to partial drying is achieved.

Example 6 was conducted to investigate in more detail the impact that higher drying temperatures {combined with 15 shorter drying times} have on the elastomeric films/gloves produced in the process. It was desired to investigate the effect of changes in the water content and surface temperature of the layer or layers of elastomeric film on the mould following application of a further layer of 20 elastomeric film ie.g. the effect of changes to precondition 2) .

The tests were conducted using Glove Composition 1, and General Procedure 1, with the process parameters 25 controlled as follows:

Step 1.2 Coagulant dipping at 60°C {60 to 62°C), pH 7,9, 9.7% Ca{M03)2.

Step 1.3 Oven set at 120°C 30 Step 1,4 Surface temperature of about S9°C {between 55 to 68°C)

Step 1,5 Dipping in Glove Composition 1 at 17.2% total solids concentration, pH 9.7, at a temperature between 25°C - 29°C for 5 seconds

Step i. 6 Drying at a high temperature of 247°c: for a time period between 10 seconds and 350 seconds, as indicated in Table 10 2015203689 01 Μ 2015

Step 1,? Pre-condition 2 details including the surface temperature was calculated for :two samples and averaged,

At the end of the procedure the water content was also calculated and recorded. The averaged data is presented 5 in. Table 10.

Step 1.I Dipping in Glove Composition 1 at 17.2% total solids......concentration, pH 9.7, 26°C - 29°C for 5 seconds1.

Observations were then made on the quality of the coating on the mould following this second dipping. 10 Steps 1.9-1.11 not conducted (2 layers only)

Steps 1,12 - 1,16 as described in General Procedure 1,

The results of this Example show that the combination of a high surface temperature with lew water content (lower 15 than 22%) results in coating difficulties and a poor product. The results also show that a combination of a lower surface temperature with a higher water content (one above 22%) result in a good quality of coating. Thirdly, the results show that -when the water content is low due to 20 the fast/high heating conditions, but the surface temperature is within the range found to give good coating results in previous examples (due to the short time of heating), despite the good surface temperature, the coating quality and product is poor, This shows that the 25 critical factor to control to achieve optimum coating and product quality is the 'water content, and not the surface temperature or duration of heating. 2015203689 01 Μ 2015

- 47 -TABLES GLOVE COMPOSITIONS USED IN EXAMPLES t

5

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Glove Composition 3 - Table 3 phr Ingredient Fart per hundred of dry "rubber" Carboxylated Nitrile Butadiene Rubber 100 Potassium Hydroxide 1,5 Cross-linking agent {i} Metallic Oxide / Mon Metallic Oxide As shown in Table 4 (ii) Sulfur o H O Antioxidant (i) Wingstal L {the product of p-eresoi and dicyclopentadiene) 0.40 Ϊ TitaniUtn Dioxide 4,0 j Colorant : Flexobrite Violet 411/78S 0»j i Flexobrite Sky Blue 72249 0.09 Flexobrite Carmine 11/78 0.01 Water Amount to reach TSC

Table 4; Cross-linking agent (CLA) used and amount Cross-Linking Agent | Part per dry hundred rubber of MgO (Magnesium Oxide) I 0.5 2.0 | 4.0 ! 8,0 TETD {Te trae thy1thiuramdi sulfide) 1 0.5 2.0 ! 4.0 00 o 5

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2015203689 01 Μ 2015

- SI TEST RESULT TABLES Table 6; CLAj pHr Coagulant Solution Ca<NOb? {%) Latex Thickness (ma·) Barrier Defect Durability Stickiness Evenness of Coating TSC {%) Temp i°o Time {sec) Layer 1 Layer '1 Laver 3 Water Leakage Compllance to ASTM D6319 {Pass/Fail 5 1 0.5 0,5 3 10 1 0.05 0 .. 05 0,,05 1/100 Pass OK Minin;;?. 1 Even 5.0 10 25 5 N.C. N.C. N.C, 1/100 Pass Good Mi :'d 1. Even 10.0 20 4 0 10 N . C . N.C. N.C. 1/100 Pass Good None Even is. 6 25 50 15 N.C. N.C. N.C. 1/100 Pass Good None Even 20.0 3 0 60 20 0.12 o o 0.04 1/100 Pass Good None Even 3 0,0 40 60 5 0,22 0.04 0.04 0/100 Pass Good None Even 2.0 MgO _ 0.5 3 10 1 N, C, N.C. N.C. 1/100 Pass Good Minimal Eve n 5,0 10 25 5 N.C. N.C, n ., e. 1/100 Pass | Good None Ever: 10.0 20 4 0 10 N.C. N.C. N.C. 0/100 Pass Good None Even 15.0 25 50 15 N.C. N.C. N.C. 0/100 Pass Good None Even 20.0 3 0 60 20 0.13 0.05 0.04 0/10 0 Pass Good None Even O o 4 0 60 5 0,21 O o 0.06 0/100 Pass Good None Ev an 4.0 0.5 3 Ϊ0 1 N.C. N. C . N.C. j 1/100 Pass Good None Even 5.0 10 25 5 N.C. N.C, N.C. j 0/100 Pass Good None Even 10.0 20 4 0 10 N.C. N.C, N.C, j 0/100 Pass Good None Evan 15,0 25 50 15 N.C. N.C. N.C. 0/100 Pass Good None Even 20.0 30 60 20 0.13 Q . 0 4 0.04 0/100 Pass Good None Even 30,0 4 0 60 5 0.21 o o O 0 01 0/100 Pass Good None Even 8.0 0.5 3 10 1 N.C. N.C. N.C. j 1/100 Pass Good None Even 5.0 10 25 5 M . C . N.C. N.C. 0/100 Pass Good None Even o o H 20 4 0 10 N.C. N. C . N.C, 0/100 Pass Good None Eve·!·· 1S.0 25 50 15 N.C. N.C. N.C, 0/10 0 Pass Good None Ever; 20.0 30 60 20 0,13 0.04 0.04 0/100 Pass Good None Even. 30.0 40 60 5 0.21 0.04 ws o o 0/100 Pass Good None Even

iGW&amp;MefS) ! JACQUELS 2015203689 01 Μ 2015 52

Table 6: (continued) CLA pHr Coagulant Solution CaiKO.-di i%) Late:-: Thickness (iran) Barrier Defect Durability (hour) Stickiness Eveness of Coat ing TSC (%) TaEtp rc; Time {sec} Layer i Layer 2 Layer 3 Water Leakage Compliance to ASTM D 6 3.13 {Pass/Fail} TETD 0.5 0.5 3 10 1 N.C. N.C. N.C. 1/100 Bass 1 2 1 5.0 10 25 5 N.C. N.C. N.C, 1/100 Pass 1 1 1 10.0 20 40 10 N.C. N.C, N. C . 0/100 Pass 1 1 1 5.5,0 25 50 15 N.C. N.C. N.C. 0/100 Pass 1 1 1 20.0 30 60 20 0.13 0 , OS 0.04 0/100 Pass 1 1 1 3 0 . 0 4 0 60 5 0.21 0.04 6.06 ο/loo Pass 1 1 1 2.0 0.5 3 10 1 N.C. M . C. N.C. 1/100 Pass 1 1 1 5 . 0 10 25 5 N.C. N.C, N.C. 1/100 Pass 1 1 I 10.0 2 0 40 10 N.C. N.C, N.C. 0/100 Pass 1 1 1 15.0 25 50 15 N.C. N.C. N.C. 0/100 Pass 1 1 1 20,0 30 60 20 0.12 0.05 0,04 6/100 Pass 1 1 1 30.0 4 0 60 5 0.20 0,05 0.05 0/100 Pass 1 1 1 4.0 0.5 3 10 1 N.C. N.C. N.C. 1/100 Pass 1 1 .1 5.0 10 25 5 N.C. N.C. N.C. 0/100 Pass 1 1 1 10.0 20 40 10 N.C. N.C. N.C. 0/100 Pass 1 1 1 IS . 0 25 50 IS N.C. N.C. N.C. 0/100 Pass 1 1 1 20.0 30 60 2 0 0,12 0.05 0.04 0/100 Pass .1 1 1 3 0,0 4 0 60 5 O <N O 0.05 0.05 0/100 Pass 1 1 ^ 1 8.0 0.5 3 10 .1 M. C , N.C. N, C . 1/100 Pass 1 1 1 5,0 10 25 5 N.C. N.C, N.C. 1/100 Pass 1 3. .1 10,0 20 40 10 N , C . N.C. N.C. 0/100 Pass 1 1 X 15.0 25 .50 15 N.C, N.C. N . C . 0/100 Pass 1 1 1 2 0.0 3 0 60 20 0.13 o o 0.04 0/100 Pass 1 1 1 3 0.0 4 0 60 5 0.2.1 0.04 0.05 0/100 Pass 1 1 1 N.C. = not calculated AU.1 dACCrLXil. 2015203689 01 Μ 2015

Table 7: 7.1 ee .1;·' Pr «- Ccrj,d8.:: 3. or. 2 Obsa r/a οι on on quality of. I’*5 dip j.syen drying oven. Snr face vaster Gacex 32of. ox dobbor Thin/ Ch.ri.okaoe 3. i f ol 3. owing TOOO Coni; sn.f Pick Fieo; ii'.iop Soak dpi W 1¾ 'Sank •-'oreeoior; Spot 0 S3 80.70 Good do do Sc Yes 2 253. 74.04 X So do So do ·,. 253. 8 3..228 X > do So do So s 4 0 87,04 ' :do So do 8 4 0 23« . 2-8 Good do So so do 1 0 __________If._________ 238,17’ Good do - So So So 12 4 0 88,3.7 ; :r·^·.·-; ' do So do 20 52 72 14 Good ' So do do 40 44 73,323 Good so So so So 40 42 73 ,. 723 ✓ / do do do So 80 4 2 74.02 Good so So So 3iO 107 4 4 «38 .. 723 Good do do do do 3.20 42 04,10 Good do So 340 34o 3. SO 44 03.07 Good SO so So 34o 3.80 41. 04 . .30 GC'Od do do do do 210 44 •£2 ’! ·' <· Good SO So do 34o 2A2 45 | 48.10 Good So So So 34o 200 38 >37.21 Good 340 do So do 8 00' 44 ' Good So so So 34o 2 50 4 0 3.5.230 So So 340 So Yes 3 50'· 4 23 3.8.78 so do So do Ye» ISO- 41 21.80 3ΪΟ SO do So 3*0 4 330 _J±_ 2 33. 23 7 34o do so do >;oo 400 * 2:5 3..08 3*0 SO 34o So so 4 330 41 83.13 330 So so So Yes; 4 230* 41 0.00 3·?ο SO So so So 5-00 4 23 7.05 3*1 ¥08 So do 70S 5238 823 0.025 So 7ft £ So do loo 000 222 3.. 7 8 do Yes SO So 7 07 0230 ?2 3.02 bo 1’eo So do Yen 700 77 3.. 823 do Yen bo So 103 7220 75 0.01 _______JS_ ¥83 do· So Yen 800 70 0.203 do Yen do so Yen 8230 823 0.02 do Vos do do loo 800 723 « . 023 do Y423 do do Ye :3 8230 00 2.78 do Yes do So Yen 1000 01 3.07 3dO Yen SO So loo wexssa.;· ?«;;« <·>, ·. .ncossis 2015203689 01 Μ 2015

Tab 1 e 7 .: {con t in ixed)

Tj.iiiiS in drying oven ίο.· roving 2 " dip Οχ'Ο-'-Ο.ΟΓίΟ.Ι t.i0 Observe t r or;. or; quality o£ 3m dip iaver Seriace Teop tC? 'Veter Content (%; Latex Pick Up 1:¾ 1 Flow Hark Rubber Lump For»» cion This/ weak .Spot Shriek-age Sample with rlrst dipped lay «2: Sample with o ecoiid -.3 i ppsd. layer 0 30 SO 77 31 Good So so so Wo 3. 4 0 34 70.4 0 Good NO NO No So 4 4 1 33 78.2 3 Good So Wo wo Wo 8 4 3 3 3 70,00 Good NO so No so 8 so 40 70.45 Good so 240 No so 10 4.3 4 2 7 7,2:: Good So Wo Wo wo 3.2 4 3 38 76.4 7 Good so So No :so 20 S3 1? 70 . 37 Good So So No so 40 42 3 7' 7 4 i, : Good So No NO so ¢0 41 38 3 3 3 3 G ood So WO NO So 30 4 0 3 S 49 33 Good So SO No SO 100 _________________::1_________________ :u; 38.47 Good SO Sc No So 120 42 3? 7.1,07 Good Sc· Sc No NO 100 44 41 05 34 Good. SO Sc No So 3.00 43 4.3 85.10 240 Sc NO No 210 40 41 45.30 < ->·ν."Μ'! So Sc Ho 240 240 44 .................11_ 81.54 V,V ·. Λ Λ So Sc No No 100-1000 Wot cowh.lWr.od r;o third dip * Re--test 2015203689 01 Μ 2015

Table 8:

Crying Oven 1 Tree isec; Pro-600(310 ion 2 Observations on the qnnlity oi the 2I:" Istex layer Surface Teop be; Water Content, {%) Laoe% Pick op Latex Flea Mark Rubber Loop Formation Thin/ Neak Spot Shrink age 240 0 55.43 Good No No No Yes 300 4 0 53,25 Good No No No No 330 4 0 47,20 Good NO No NO Yes 400 40 11.5 6 No Yes No No Yes 430 4 0 21 , 31 No Yes No No Ye s 500 4 0 4,05 No Yes No NO Yes S 3 0 4 0 2.08 NO Yea No No Yes 500 40 6,15 No Yes No NO Yes, 650 40 7.58 NO Yes No No Yes 700 4 0 0.79 NO Yes NO No Yes 7 SO 4 0 7.44 No Ye.3 No NO Yes 800 40 0,6 5 No Yes NO No Yes 550 4 0 4.13 No Yes No NO Yes 800 4 0 5.58 NO Yes NO No Yes 350 4 0 4,8 5 No Yes No NO Yes 1000 4 0 5.38 NO Yes NO No Yes msmj ««***<19 *»08*43·.*«.·» .acees·.® 2015203689 01 Μ 2015

Table 9&amp;:

Propose Pre · Condition i Surface Temp i°C} Actual Surface Temp After Oven Heating - - -'cations after iB;; dip lever Observation on first latex dip layer Latex Pick Up Latex Flow Mark Rubber Lump Formation Thin / Weak Spot Shrinkage <25 25 Pick up okay Good Good No Yes No <30 29 Pick, up okay Good Good No Yes No 3 0-45 3 9 Pick, up okav Good Good No No No 45-53 49 Pick up < < Good Good NO No NO 53--69 61 Pick up 'y'; Good. Good No No No 70-80 70 Pick up ot;ay Good Moderate NO No No 75 Pick up okay Good Moderate No No No 8 0 Pick, up okay Good. Moderate NO No No 80-85 84 Pick, up okay Good Bad No No No 85-95 92 Pick up okay Good Bad No Yes Yea 95-120 106 Pick up okay Good Bad No Yes Yes >120 122 Pick up okay but gelling film shrinkage at pale; Good Bad No Yes Yes 86352HL1 P«OK2>AJ.i JACQUES. 2015203689 01 Μ 2015

Table 9Β:

Propose Pre-Condition 2 Surface Temp PC) Pre-Condition 2 Observations after 2iid dip layer Surface Temp before 2r,d Latex Dip Water Content i%) Observation on surface after 2κα Dip Layer Latex Pick. Latex f loo-mark Thin/ Weak Spot Rubber Lumps or Shrink-age <25 25 64,24 Pick up okay Good Good bo No 25-30 28 62.66 Pick up okay • 'x : Good No No 30-35 33 64.36 Pick: up okay •0' ou Good No NO 35-55 4 5 23.14 Pick up okay Good Goo / No NO 55-65 60 1,13 Pick up ok-iy Bad d-i; V. Yes No 65-75 70 2,23 Pick up -stay Bad. Bed Yes No 75-90 83 1.07 Pick up okay Bad Bad Yes No 30-120 105 0.82 Pick up okay Bad Bad Yes No >120 120 2,12 Second, layer of latex cannot be coated evenly on the lsc layer Bad Bad Yes No

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Table 9C:

Propose Pre-Condition 3 Surf ace Temp iV) Pre-Condition 3 Observations after dip layer Surface Temp before 3**‘ Latex Dip Water Content. {% 5 Observation on surface after 3;’tt Dip Layer Latex Pick Op Lat ex flow mark Thin/ Weak Spot Rubber Lumps or 3 hrinkage <25 23 61.62 Pick up okay Good Good bo No 25-30 28 66.57 Pick up okay Good Good bo No 30-35 33 65.20 Pick up okay Good Good No No 35-55 46 39.54 Pick up okay Good Good NO No 55-65 70 0.46 Third lft.ex iaye;: cannot be coated on to the second layer Bad Bad bo No 65-75 7 4 4.3 1 Bad Bad Do No 75-90 83 2,88 Bad Bad NO No 90-120 104 0.62 Bad Bad No No >120 121 0.64: Bad Bad bo No 2015203689 01 Μ 2015 59

Table 10:

Drying Oven Time isec) Pre · Condi t i on 2 Observation:? on. 2"'s dipped layer Surface Temp TO) Wafer Content C%) Later. Pick Up Latex Flow Nark Robber Lump Formation Thin/ Weak Spot Shrinkage 10 4 9 74.84 Good No No Mo No 20 54 66..7 6 Good NO No Mo No 30 55 60 .. 01 Good No No Mo No 4 0 56 67.36 Good Mo No No No 50 SS 72.39 Good Mo No No No SO 55 62.65 Good NO No NO No 7 0 55 69.36 flood No Mo No NO 80 56 54. . 47 Good No No NO No 110 58 52.43 Good No No No NO 120 57 35.20 Good. No No No No 13 0 61 24.45 Good Yea No NO No 140 f·, 20.51 No Yea No No NO .17 0 i. i 5.56 No Yes Mo No No 2 00 54 2.30 No Yes No No NO 2 3 0 80 9.27 No Yes NO No NO .260 85 .6.08 NO Yes No Mo NO 2 90 88 7.69 No Yes No NO No 320 116 2.03 No Yes No NO No 350 137 3.56 NO Yes No No No 2015203689 01 Μ 2015

For all of the Examples, the following testing techniques were used. 5

General Testing Procedures

The testing procedures were conducted in accordance with A§1# S 6319-00 {Reapproved 2005}, based on a 100 sample test size. This ASTM standard is available from ASTM International, and details the standard specifications and testing standards used for testing nitrile rubber examination gloves for medical applications. These tests can be applied similarly to non-glove multilayer films. 15 Barrier Defects

The barrier defects test for detecting holes was conducted in accordance with ASTM D 5151-06, which is incorporated within ASTM D 6319-00. 20 This test involves pouring a minimum of 1000cmj! of water having a room temperature of 15°C to 3GeC into the top of a mindral to which the glove is affixed. The glove is then visually assessed for immediate water leakage and water leakage after 2 minutes. The extent of water leakage by a 25 sample of 100 gloves was rated as follows: 1 = Excellent : <1/100 2 ^ Good : 2/100 3 = Average : 3/10® 4 = Poor : 4/100 3 0 5 === Very Poor : 5/100

Water content

The water content of any film on a mould, which may be in the shape of a glove, is determined by the following 35 method: (i) Weigh the mould together with wet coated film (precondition film) and record the weight Ylt

«3*3255,.? JACOUctS - 61 ·· 2015203689 01 Μ 2015 (ii) Dry (i) in an oven for 6 0 aiinufces at: 120°C. (iii) Place (ii) in a desiccator for 10 minutes for cooling. (iv) Weigh (ill) and record the :weight, Y3 {dry files and 5 mould). (v) Calculate Water content as { {Yi--Y2} / (Yi-Y0) } x 100%, where Y.) is the uncoated mould net Weight.

Stickiness of gloves 10 Stickiness of gloves was assessed on a 100 glove sample size. The gloves were assessed by persons who wear elastomeric gloves as part of their work and the level of stickiness of batches of 20 gloves at a time was assessed, using the following rating system: 15 1 - not sticky ("none") 2 = less sticky ("minimal") 3 = sticky ("sticky") 4 = very sticky {"very") 5 = very high stickiness ("high"} 2 0 The average of the 5 x 20 glove batches -was assessed to the closest round figure to give the stickiness level for the 100 glove sample size.

Latex pick-up 25 Latex pick-up refers to the pick-up or wetting of the composition for forming an elastomeric film on the mould, or any outer coating or layer on the mould. This is determined by visual inspection as being good (marked "good") or bad/absent ("poor"/“no"}. 30

Latex flow mark

Latex flow mark refers to the appearance of a flow mark where the Composition appears to»flow off the mould, or off the composition that has been coated or deposited 35 prior to the subject coating, causes of a flow mark, can include a poor gel strength of the composition during dipping whereby the composition takes a longer time to

ess.'is.'...! (OKMaarn: As».! JACCHtfl.S - 62 - 2015203689 01 Μ 2015 deposit on the mould or previously deposited layer{s), poor pick-up or poor adhesion, This is assessed by visual inspection as being;: present (recorded as "yes", or "bad" or "moderate" to indicate degree) or not present (recorded 5 as "no" or "good"),

Evenness of coating

Whether the coating is even is assessed visually, and recorded as being "even" or not even ("not"}. X w

Adhesion between layers of elastomeric film Adhesion between layers is assessed by visual inspection during the process of dipping - that is, at the point, at which the mould is withdrawn from the composition, or 15 through assessment of the final product.

Rubber Lump Formation

Rubber lump formation refers to the formation of lumps of the composition for forming the elastomeric film on the 2Θ mould, or a rough/lumpy surface of the composition on the mould. This can he assessed at the point when the mould is Withdrawn from the composition, or in the final product.. This is assessed by visual inspection as being present (recorded as "yes”) or not present {recorded as.....

Thin or weak spots

The presence or absence of thin or weak spots is tested by inflating the final product with air, and visually inspecting the product for thin or weak spots. Thin or weak spots are recorded as being present ("yes”) or absent {"no*5 .

Shrinkage 35 A small level of shrinkage is permitted in the products, and arises as a result of the evaporation of moisture from the layers of composition for forming the elastomeric m 2015203689 01 Μ 2015 film. For a glove product of 27cm in length fat the point in time when the mould is withdrawn from the composition for forming:: the last layer) , there is normally shrinkage of about 0.5 cm in length after a few seconds (less than 5 10 seconds) from the point of withdrawal from the composition but before drying. In the case of a glove product, shrinkage of four times this level, or greater than 2 cm in a length of 27cm, is considered to be an unacceptable level of shrinkage, and is recorded in 10 shrinkage testing tables as being present {"yes"). If the level of shrinkage is 1cm or less, this is recorded as being not present {"no").

Dur&amp;bi1ity Test ing. 15

The following test steps were taken to determine durability of gloves in a range of temperature and humidity conditions. The gloves were worn by persons involved in a range of duties, including at least the 20 following three duties: (i) office work, {i1)packaging of products into boxes and (iii) laboratory/quality control/R&amp;D work, 1, Condition gloves for 30 minutes in desiccator. 25 2. Provide gloves to at least 3 testers involved in the three duties - office work, packaging and laboratory work. 3. Record the time taken for the glove to tear when used by that tester. 4. Each tester tests 5 samples of gloves and records the 30 time to tearing for each sample.

For the 15 trial results, the average time before tearing of the glove samples was determined. The durability fas then classified as follows: 35 1 hours or less - poor durability ("poor" in table 6} >1 hours to 3 hours - acceptable durability {"OK"} >3 hours - good dux'abilitv ("good") . 2015203689 01 Jul 2015 - 64 -

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as 5 "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims (41)

1. THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

   1. A method for producing multi-layered elastomeric film or article, the method comprising: (i) dipping a mould into a composition for producing an elastomeric film having a total solids content of between 5% - 40% to produce a layer of elastomeric film composition on the mould, (ii) partially drying the layer of elastomeric film composition on the mould to reduce the total water content of the elastomeric film composition to a level of not less than 22%, (iii) dipping the mould coated with the partially dried layer of elastomeric film composition into a composition for producing an elastomeric film having a total solids content of between 5% - 40% to produce a further layer of elastomeric film composition on the mould, and (v) drying and/or curing the layers of elastomeric film composition on the mould.
2. 2. The method of claim 1, wherein step (v) comprises drying and curing the layers of elastomeric film composition on the mould.
3. 3. The method of claim 2, wherein the partial drying step (ii) is controlled to reduce the water content to a level below 90%, but not less than 22%.
4. 4. The method of claim 3, wherein the partial drying step (ii) is controlled to reduce the water content to a level below 80% but not less than 22%.
5. 5. The method of claim 4, wherein the partial drying step (ii) is controlled to reduce the water content to a level below 80% but not less than 25%.
6. 6. The method of claim 5, wherein the partial drying step (ii) is controlled to reduce the water content to a level below 75% but not less than 25%.
7. 7. The method of claim 5, wherein the partial drying step (ii) is controlled to reduce the water content to a level below 77% but not less than 30%.
8. 8. The method of any one of the preceding claims, wherein the partial drying step (ii) is controlled so that at the end of partial drying the film surface temperature of the elastomeric film composition on the mould is between 25°C-85°C.
9. 9. The method of any one of the preceding claims, wherein the partial drying step (ii) achieves a film surface temperature of between 30°C and 80°C.
10. 10. The method of any one of the preceding claims, wherein the partial drying step (ii) achieves a film surface temperature of between 40°C and 80°C.
11. 11. The method of any one of the preceding claims, wherein the partial drying step (ii) comprises subjecting the coated mould to drying conditions at a temperature above ambient.
12. 12. The method of claim 11 wherein the partial drying step (ii) comprises applying drying radiation to the coated mould.
13. 13. The method of any one of the preceding claims, wherein the mould is subjected to heating prior to dipping step (i) .
14. 14. The method of claim 13, wherein the heating step comprises heating to raise the surface temperature to a temperature in the range of 25°C to 85°C.
15. 15. The method of any one of the preceding claims, further comprising the steps of: (a) dipping the mould into a coagulant containing multivalent ions in solution, and (b) drying or partially drying the coagulant-dipped mould, prior to step (i).
16. 16. The method of claim 15, wherein the mould is heated prior to dipping into the coagulant.
17. 17. The method of claim 16, wherein the mould is heated to a surface temperature in the range of 25°C to 85°C.
18. 18. The method of claim 16, wherein the mould is heated to a surface temperature in the range of 30°C to 7 0°C.
19. 19. The method of any one of claims 15 to 17, wherein the multivalent ions are multivalent metal ions.
20. 20. The method of any one of claims 15 to 17, wherein the coagulant containing multivalent ions in solution is selected from the group consisting of calcium, magnesium, barium, zinc and aluminium, with a counterion selected from the group consisting of halides, nitrate, acetate and sulphate, in solution.
21. 21. The method of any one of claims 15 to 20, wherein the coagulant is selected from the group consisting of calcium halide, calcium nitrate, calcium acetate, calcium sulphate, magnesium halide, magnesium nitrate, magnesium acetate, magnesium sulphate, barium halide, barium nitrate, barium acetate, barium sulphate, zinc halide, zinc nitrate, zinc acetate, zinc sulphate, aluminium halide, aluminium nitrate, aluminium acetate and aluminium sulphate.
22. 22. The method of any one of claims 15 to 21, wherein the concentration of coagulant in solution is between 1 and 20% by weight.
23. 23. The method of any one of claims 15 to 22, wherein the concentration of coagulant in solution is between 1.0 and 15% by weight.
24. 24. The method of any one of the preceding claims, wherein the dwell time of the mould in the dipping tank in step (i) is between 1.0 to 30 seconds.
25. 25. The method of any one of the preceding claims, wherein the dwell time of the mould in the dipping tank in step (i) is between 1.0 to 10.0 seconds.
26. 26. The method of any one of the preceding claims, wherein the temperature of the composition into which the mould is dipped in step (i) is within the range of 10°C to 60°C.
27. 27. The method of any one of the preceding claims, wherein the film or article has between 2 to 15 layers.
28. 28. The method of any one of the preceding claims, wherein, between steps (ii) and (iii), a partial drying step (ii) and a dipping step, is performed at least once, said partial drying step comprising drying of the elastomeric film composition on the mould to reduce the total water content of the elastomeric film composition to a level of not less than 22%, and said further dipping step comprising dipping the mould coated with the partially dried layer of elastomeric film composition into a composition for producing an elastomeric film having a total solids content of between 5% - 40% to produce a further layer of elastomeric film composition on the mould.
29. 29. The method of claim 28, wherein the film or article has between 3 and 15 layers,
30. 30. The method of any one of the preceding claims, wherein each layer of the film constitutes between 6 and 90% of the total film thickness.
31. 31. The method of any one of the preceding claims, wherein the composition for producing an elastomeric film comprises an elastomer-forming polymer and a cross-linking agent.
32. 32. The method of any one of the preceding claims, wherein the first composition for producing an elastomeric film is a synthetic elastomeric composition.
33. 33. The method of any one of the preceding claims, wherein dipping step (i) involves dipping a mould into a first composition for producing an elastomeric film comprising an elastomer-forming polymer and having a total solids content of between 5% and 40%; and dipping step (iii.) involves dipping the mould coated with the partially dried layer of elastomeric film composition into a second composition for producing an elastomeric film comprising an elastomer-forming polymer, wherein the second composition has a total solids content of between 5% and 40%, to produce a further layer of elastomeric film composition on the mould, and wherein the identity of the elastomer-forming polymer in the second composition is the same as the elastomer-forming polymer in the first composition.
34. 34. The method of any one of the preceding claims, wherein the total solids content of the composition for producing an elastomeric film in step (i) is between 5 and 20% by weight.
35. 35. The method of any one of the preceding claims, wherein the multilayered elastomeric film or article is a glove, the method comprising; - measuring the mass of a sample glove product at the point of completion of the partial drying step (ii), - driving off the remaining moisture in the sample glove product to obtain the dry mass of the product, and - determining from the two values the water content of the sample glove product following the partial drying step.
36. 36. The method of claim 35, comprising controlling the partial drying step to maintain the total water content within the precondition range for the elastomeric film composition following partial drying, based on the sample glove product results.
37. 37. The method of any one of the preceding claims, wherein the mould is a glove-shaped mould, and the elastomeric article is a glove.
38. 38. The method of claim 37, wherein the glove has a thickness in the range of 0.01-3.0mm.
39. 39. The method of claim 37, wherein the glove has a thickness in the range such as 0.01-0.3mm.
40. 40. A film or article produced by the method of any one of the preceding claims.
41. 41. A method for the production of a multi-layered elastomeric film or article, or a film, article or glove produced thereby, substantially as herein described with reference to the accompanying Examples, excluding comparative Examples ,