GB2638793A

GB2638793A - Coating

Info

Publication number: GB2638793A
Application number: GB2405318.3A
Authority: GB
Inventors: Masood Ali Shah Syed
Original assignee: TILSATEC Ltd
Current assignee: TILSATEC Ltd
Priority date: 2024-04-15
Filing date: 2024-04-15
Publication date: 2025-09-03
Also published as: WO2025219697A1; GB202405318D0

Abstract

The coating 10, 12 comprises waterborne polymer resin and binding agent. Preferably the resin is polyurea and the binder is added as a thickened aqueous premix comprising polyelectrolyte or polysaccharide and including a water retaining agent and polyurethane. The preferred coating applied to a fabric 8 glove has a viscosity of 400-1600 cps. The coating is preferably applied to a preheated wearable item, gelled for 5-20 minutes and cured at 95-105°C. The disclosed protective glove comprises nylon fabric 8 coated with two layers 10, 12 comprising waterborne polyurea, sodium carboxymethyl cellulose binder, water based polyurethane dispersion and pigment.

Description

COATING

FIELD

The present disclosure relates to a coating for application to a substrate, in particular but not exclusively for application to wearable protective equipment, for example a glove.

The disclosure also relates to a wearable item comprising said coating, a method of preparing said coating and a method of making said wearable item.

BACKGROUND

In many industries and occupations, protective equipment is worn to minimise exposure to hazards that can cause workplace injury and/or harm. For example, gloves and other protective equipment can be worn to protect against abrasion, cuts and/or contamination, amongst other hazards.

It is known to apply coatings to gloves to provide desired protective properties, for example, polyurethane based coatings are often used. However, the use of polyurethane coatings requires the use of dimethylformamide (DMF) as a solvent. DMF is known to be readily absorbed through the skin and can be toxic to the liver, and irritate the skin, eyes and respiratory tract. Accordingly, there is the desire to reduce the use of DMF in favour of safer alternatives.

KR20150046992 discloses the use of a polyurea based coating which does not require the use of DMF. However, this coating has been found to provide poor abrasion resistance, results in a non-uniform coating when applied to a glove, and has a poor coating finish when applied to fabrics comprising engineered yarns.

Accordingly, it is an object of the present disclosure to overcome or at least mitigate some of the problems associated with the prior art.

SUMMARY

In accordance with an aspect of the disclosure, a coating is provided for application to a substrate, wherein the coating comprises a coating formulation comprising a waterborne polymer resin and an additive component. Optionally, the additive component comprises a binding agent. Optionally, the coating formulation comprises an aqueous system.

As used herein, the term "waterborne polymer resin" will be understood to mean a polymer resin for which water is used as the carrying medium, rather than a solvent. For example, the polymer resin may be water-soluble, water reducible or water dispersed. Further, as used herein, the term "aqueous system" will be understood to mean a mixture or solution in which water is the main solvent.

Coating formulations disclosed herein comprise an aqueous system and further comprise a waterborne polymer resin. Accordingly, the main solvent is water and the use of other more harmful solvents, such as DMF, is not required. Consequently, the negative health implications associated with the use of such harmful solvents are avoided.

Furthermore, due to the presence of the binding agent, the coatings disclosed herein have been found to have enhanced structural and physical properties, in particular in comparison to the coating disclosed in KR20150046992.

For example, when applied to a wearable item such as a glove, the coatings disclosed herein have been found to provide improved levels of performance and durability, in particular with respect to protection against abrasion. It has also been found that these improvements are achieved when using a variety of substrates, including engineered yarns, e.g. cut-resistant yarns.

Without wishing to be bound by any particular theory, it is believed that the binding agent facilitates the dispersion of the waterborne polymer in the aqueous system. For example, it is believed that the binding agent bonds with water chemically and/or physically to provide a structure in the aqueous system that facilitates even dispersion of the waterborne polymer. This results in an increase in the degree of polymer cross linking, which modifies the rheology of the aqueous system and results in improved film formation when the coating is applied to a substrate.

In some embodiments, addition of the binding agent results in a thickening or increase in viscosity of the aqueous system.

In some embodiments, it is believed that the binding agent acts by dispersing evenly, absorbing water and swelling to provide a structure in the aqueous system that facilitates cross linking of the waterborne polymer resin. In this way, the aqueous system thickens such that its viscosity is increased.

As will be described in further detail below, it has been found that the coating formulation disclosed herein enables improvements in the process of manufacturing a coated substrate to be achieved.

Since water is the main solvent for the coating formulations disclosed herein and more harmful solvents, such as DMF, are not required, the coating formulations disclosed herein are better for the environment than those requiring the use of such harmful solvents. Since no harmful solvents are used, there is no contribution of such harmful solvents to air pollution. The production process involves no water leaching or bathing process, thereby saving water. Consequently, there is no effluent treatment required, saving energy and reducing carbon emissions. Overall, there is no waste discharged to nature, reducing hazardous effects to people, the environment, marine and wildlife.

Optionally, the waterborne polymer resin comprises a polyurea resin.

By using a polyurea based coating, water can be used as the carrying medium for the polymer resin. Therefore, the use of harmful solvents, e.g. DMF, is not required, hence the harmful effects associated with such solvents can be avoided.

Optionally, the binding agent is water soluble at room temperature and pressure (RTP).

In this way, the binding agent dissolves in the water present in the aqueous system and is more evenly dispersed in the water. Accordingly, the action of the binding agent to provide structure to the aqueous system, hence increasing the degree of polymer cross linking, is enhanced.

The term "room temperature and pressure (RTP)" as used herein will be understood to mean a temperature of 25°C (298K) and a pressure of 1 atmosphere.

In some embodiments, the binding agent comprises a hygroscopic binding agent. In this way the binding agent acts as a water retaining agent.

Optionally, the binding agent comprises a water retaining agent.

Without wishing to be bound by any particular theory, it is believed that the water retaining agent absorbs water present in the aqueous system, thereby creating a structure in the system. This structure facilitates dispersion and cross-linking of the waterborne polymer, resulting in an improved rheology of the aqueous system.

Optionally, the binding agent comprises a polar group. Optionally, the binding agent comprises a carbonyl, hydroxyl and/or carboxymethyl group.

The presence of polar groups facilitates bonding of the binding agent with water in the aqueous system, thereby facilitating creation of a structure in the system. This facilitates dispersion and cross linking of the polymer, resulting in an improved rheology of the aqueous system.

Optionally, the binding agent comprises a polyelectrolyte, for example an anionic polyelectrolyte.

It will be understood that a polyelectrolyte is a polymer whose repeating units comprise an electrolyte group. When such a binding agent is placed in water, the electrolyte groups dissociate resulting in charged polymers, thereby facilitating bonding of the binding agent with water.

Optionally, the binding agent comprises a polysaccharide, e.g. cellulose.

In some embodiments, the binding agent comprises one or more of sodium carboxymethyl cellulose (NCMC), carboxymethyl cellulose (CMC), hydroxyl propyl methyl cellulose (HPMC), and polyanionic cellulose (PAC).

Optionally the coating formulation, optionally the additive component, further comprises a polyurethane resin.

By including a polyurethane resin, it has been found that the performance of the coating formulation is enhanced. Without wishing to be bound by any particular theory, it is believed that the binding properties of the polyurethane resin enhance the formation of a structure in the aqueous system that facilitates even dispersion of the waterborne polymer.

Furthermore, the heat resistant properties of the polyurethane resin improve the heat resistant performance of the resulting coating. It has also been found that the inclusion of a polyurethane resin improves the tensile strength of the cured coating and also improves adhesion of the coating to the substrate.

Optionally, the polyurethane resin comprises a comprises a water-based polyurethane dispersion (WPUD).

As used herein, the term "water-based polyurethane dispersion" is understood to mean a polyurethane polymer resin dispersed mainly in water, rather than a solvent. In this way, the need for harmful solvents is reduced or avoided.

In some embodiments, the polyurethane resin may be oil-based. In other words, the polyurethane resin is carried by petroleum and/or mineral solvents.

Optionally, the polyurethane resin comprises a bio-based polyurethane.

As used herein, the term bio-based polyurethane is understood to mean a polyurethane made from a natural polyol, rather than a synthetic polyol. In this way, bio-based polyurethane provides the advantages of low environmental impact, easy access and good biodegradability.

Optionally, the polyurethane resin comprises an anionic polyurethane resin.

It has been found that anionic polyurethane resin comprises particle sizes which are smaller than those of cationic resins. Accordingly anionic resins disperse more easily in the aqueous system. In this way, the action of the binding properties of the polyurethane resin to provide structure to the aqueous system is enhanced, hence increasing the degree of polymer cross linking.

In some embodiments, the polyurethane resin comprises a polyester-polyurethane. In some embodiments, the polyurethane resin comprises a polyether-polyurethane.

Optionally, the additive component comprises a premix comprising the binding agent and 30 water.

Optionally, the premix is allowed to thicken for a predetermined time and/or until the premix has reached a desired viscosity.

Optionally, the predetermined time is up to 4 weeks, for example for 2-3 weeks.

Optionally, the predetermined time is less than the time taken for the premix to solidify.

Optionally, the desired viscosity is 95000cps or less when measured at a temperature of 26 to 30°C on a Brookfield viscometer using a number 3 spindle rotating at 1rpm.

By premixing the binding agent and water together as a premix, the premix can be allowed to thicken prior to addition to the waterborne polymer resin.

In some embodiments, the premix thickens due to the binding agent swelling and dispersing in water, in this way, the viscosity of the additive component increases due to the action of the binding agent.

In some embodiments, when the predetermined time has passed and/or a desired viscosity has been reached, the additive component is then added to the waterborne polymer resin. The additive component advantageously modifies the rheology of the waterborne polymer resin. It is believed that this is in part due to the viscosity of the additive component. Additionally, and without wishing to be bound by any particular theory, it is believed that -OH groups in the additive component and in the waterborne polymer resin attract each other electrostatically, causing hydrogen bonds. This helps the building of more ordered polymer structures, which helps in good film formation when the coating is applied to a substrate.

Optionally, polyurethane resin is introduced to the waterborne polymer resin along with the additive component.

Optionally, in the case where the binding agent is added directly to the waterborne polymer resin, without previously being added to water and allowed to thicken, the polyurethane resin may be introduced to the waterborne polymer resin after a predetermined time has passed and/or the aqueous system has reached a desired viscosity.

Optionally, the premix comprises the polyurethane resin.

In the case where the polyurethane resin comprises a water-based polyurethane dispersion (WPUD), the water in the premix may be provided by the WPUD. In other words, a separate amount of water may not be provided.

In some embodiments, once the coating formulation has been prepared (i.e. after the binding agent and polyurethan (when present) has been added to the polyurea resin), the coating formulation is allowed to thicken for a predetermined time or until a desired viscosity has been reached. In some embodiments, the predetermined time may be a time in the range of from about 6 hours to about 60 hours, for example in the range of from about 12 hours to about 48 hours, for example, in the range of from about 12 hours to about 24 hours, for example, about 36 hours, for example about 48 hours.

In some embodiments, the desired viscosity of the coating is in the range of from about 400cps to about 1600cps, for example in the range of about 400cps to about 1250cps, for example 600cps, for example 1000cps, for example 1250cps. Viscosity is measured at temperature of 26 to 30°C on a Brookfield viscometer using a number 3 spindle rotating at 20rpm.

In some embodiments, the coating viscosity is approximately 600cps at a maturation time of 12-24 hours. In some embodiments, the coating formulation viscosity is approximately 1000cps at a maturation time of 36 hours. In some embodiments, the coating formulation viscosity is approximately 1250cps at a maturation time of 48 hours.

Viscosity is measured at temperature of 26 to 30°C on a Brookfield viscometer using a number 3 spindle rotating at 20rpm.

In some embodiments, the coating has a viscosity in the range of from about 400cps to about 1600cps, for example in the range of about 400cps to about 1250cps, for example 600cps, for example 1000cps, for example 1250cps, wherein said viscosity is measured at temperature of 26 to 30°C on a Brookfield viscometer using a number 3 spindle rotating at 20rpm.

Optionally the substrate comprises a fabric. In some embodiments, the substrate comprises one of more of: cotton, nylon, polyester, Spandex, HPPE (high performance polyethylene, glass, steel, plant-based fibres, biobased fibres, starch-based fibres, recycled nylon, recycled polyester, regenerated nylon, graphene-based fibres, carbon yarns.

In some embodiments, the fabric comprises: 100% cotton; 100% nylon; 100% polyester; a mix of nylon and spandex; a mix of nylon, HPPE and spandex; a mix of nylon, HPPE, glass, and spandex; a mix of nylon, HPPE, glass, steel and spandex; plant-based fibres; biobased fibres; starch-based fibres; recycled nylon; recycled polyester; regenerated nylon; graphene based fibres; or carbon yarns.

In some embodiments, the desired viscosity of the coating is selected based on the substrate, for example the type of fabric substrate.

In a further aspect of the present disclosure, a wearable item of protective apparel is provided comprising a fabric to which the coating disclosed herein has been applied.

It has been found that the wearable item comprising the coating disclosed herein has improved levels of performance and durability, in particular with respect to protection against abrasion. Furthermore, as will be described in further detail below, the process of manufacturing the wearable item is also improved. It has also been found that these improvements are seen when using a variety of fabric types, including engineered yarns, e.g. cut-resistant yarns.

Optionally, the wearable item comprises a glove.

In accordance with a further aspect of the present disclosure, a method of preparing a coating for application to a substrate, wherein the method comprises: a. providing an additive component comprising a binding agent; b. providing a waterborne polymer resin; and c. introducing the additive component to the waterborne polymer resin; optionally wherein the coating comprises an aqueous system.

As described above, it is believed that the binding agent facilitates the dispersion of the waterborne polymer in the aqueous system. For example, it is believed that the binding agent bonds with water chemically and/or physically to provide a structure in the aqueous system that facilitates even dispersion of the waterborne polymer. This results in an increase in the degree of polymer cross linking, which modifies the rheology of the aqueous system and results in improved film formation when the coating is applied to a substrate.

Optionally, the method further comprises providing a polyurethane resin and introducing the polyurethane resin to the waterborne polymer resin.

Optionally, the method further comprises the step of introducing water to the binding agent to form a mixture, and wherein the method further comprises allowing the mixture to thicken, i.e. increase in viscosity.

Optionally, allowing the mixture to thicken comprises leaving the mixture for a predetermined time and/or until it has reached a desired viscosity.

Optionally, the additive component, comprising the binding agent, is introduced to the waterborne polymer resin, such that the mixture comprises water from the waterborne polymer resin.

In other words, by introducing the binding agent to the waterborne polymer resin, the binding agent is mixed with water from the waterborne polymer resin to form a mixture. Put another way, the binding agent is added directly to the waterborne polymer resin, without previously being allowed to thicken in water. In such embodiments, the binding agent mixes with water in the aqueous system, thereby increasing the viscosity of the aqueous system. In some embodiments the binding agent swells and disperses in water, thereby increasing the viscosity of the aqueous system.

By increasing the viscosity of the aqueous system, it is believed that the binding agent provides a structure to the aqueous system that facilitates the dispersion of the waterborne polymer in the aqueous system, enabling an increase in the degree of polymer cross linking to be achieved. This modifies the rheology of the aqueous system and results in an improved coating when the coating is applied to a substrate.

Optionally, polyurethane resin is introduced to the waterborne polymer resin after the mixture has been allowed to thicken, e.g. for the predetermined time or until a desired viscosity has been reached.

Optionally, the additive component comprises a premix comprising the binding agent and water, such that the mixture comprises the premix.

In other words, the binding agent is introduced to water prior to being added to the waterborne polymer resin.

Thickening of the premix prior to addition to the waterborne polymer resin may be advantageous in achieving a desired viscosity of the resultant coating formulation.

Optionally, the premix is allowed to thicken prior to being introduced to the waterborne polymer resin.

Optionally, the premix is allowed to thicken for a predetermined time prior to being introduced to the waterborne polymer resin and/or wherein the premix is allowed to thicken until it has reached a desired viscosity.

Optionally, the premix is allowed to thicken for up to 4 weeks, for example for 2-3 weeks. Optionally, the predetermined time is less than the time taken for the premix to solidify.

Optionally, the desired viscosity is 95000cps or less when measured at a temperature of 26 to 30°C on a Brookfield viscometer using a number 3 spindle rotating at 1rpm. Optionally, the premix further comprises the polyurethane resin.

Optionally, the polyurethane resin is introduced to the waterborne polymer resin along with the additive component.

In a further aspect of the disclosure, a method of making a coated substrate is provided, the method comprising: a. preparing a coating in accordance with the method disclosed herein; b. providing a substrate; and c. applying the coating to the substrate.

In a further aspect of the disclosure, a method of making a wearable item of protective apparel is provided, the method comprising: a. preparing a coating in accordance with the method disclosed herein; b. providing a substrate; c. applying the coating to the substrate; wherein the substrate is arranged to adopt the form of the wearable item before or after the coating is applied to the substrate.

The coating formulation disclosed herein has been found to be less sensitive to humidity than those of the prior art, in particular those disclosed in KR20150046992. Without wishing to be bound by any particular theory, it is believed that the way in which the binding agent bonds to water results in a coating formulation that is less sensitive to water, thereby resulting in improvements in the method of applying the coating to a substrate.

For example, in prior art methods, excess water in the coating formulation can negatively impact the quality of the film coating. For example, excess water in the coating formulation during the curing process can cause blisters and/or bubbles to form in the film. It is believed that such blisters and/or bubbles form in areas of high water concentration, which result from the absence of stability and uneven distribution of water molecules in the prior art coatings. Accordingly, an evaporation step is needed in some prior art methods to reduce the negative impacts of water. Further, prior art methods have also been found to be more sensitive to temperature than the methods disclosed herein.

When applying the coating disclosed herein to a substrate, there is no need to include an evaporation step to reduce the amount of water in the coating formulation. It is believed that this is due to the presence of the binding agent and the way in which it bonds with water in the system to provide an even distribution of water molecules in the system. Accordingly, a simplified, quicker, and more reliable method of producing a wearable item is achieved.

Optionally, after applying the coating to the substrate, the coated substrate is cured at a temperature of or above 70°C, for example at or above 75°C. For example, at a temperature in the range of from about 75°C to about 95°C.

Optionally, after applying the coating to the substrate, the coated substrate is cured at a temperature of or above 90°C, for example at a temperature of or above 95°C, for example at a temperature in the range of from about 95°C to about 105°C.

The coating formulation disclosed herein has been found to be less sensitive to temperature than those of the prior art, in particular those disclosed in KR20150046992. Without wishing to be bound by any particular theory, it is believed that the way in which the binding agent bonds to water acts to retain water in the structure of the aqueous system, thereby reducing the extent to which water evaporates from the system at higher temperatures which can detrimentally affect the coating. This results in a coating formulation that is less sensitive to temperature.

Since the binding agent bonds to water in the system, the impacts of water evaporation are mitigated. Consequently, higher curing temperatures can be used as compared to coatings of the prior art. Furthermore, the effects of humidity are reduced.

In some embodiments, the coated substrate is cured for less than 60 minutes, for example in the range of from about 5 to about 45 minutes, for example in the range of from about 20 to about 40 minutes, for example in the range of from about 25 to about 35 minutes, for example in the range of from about 25 to about 30 minutes, for example in the range of from about 10 to about 30 minutes.

Optionally, prior to curing, the coating is allowed to gel for a predetermined gelling duration, for example, a predetermined gelling duration in the range of from about 5 minutes to about 20 minutes.

As will be understood by those skilled in the art, "gelation" is when a liquid phase turns to solid form. It has been found that the gelling duration helps the coating be at least partially absorbed into the substrate (e.g. a fabric) and form an even film or coating on the surface. This helps a coating layer to set uniformly on a substrate and support later exposure to relatively high temperatures required for curing e.g. temperatures in the range of about 90 to about 95°C.

In some embodiments, the coating is allowed to gel at RTP.

Optionally, the substrate is heated prior to the coating being applied.

In some embodiments, the substrate is heated to a temperature in the range of from about 25°C to about 75°C, from example from about 35°C to about 65°C, optionally prior to the coating being applied.

In some embodiments, a mould is provided and the substrate is applied to the mould. In some embodiments, the mould may be heated prior to lining. In some embodiments, the mould may be lined at RTP.

It has been found that heating the substrate and/or mould facilitates faster gelling of the coating and more even coating of the substrate.

Furthermore, it has been found that heating the substrate and/or mould helps to control and/or determine the extent to which the coating has penetrated into the fabric and/or been absorbed into the fabric. Sufficient absorption or penetration provides improved adhesion of the coating to the fabric. However, too much absorption or penetration can be detrimental to the flexibility of the coated glove. Accordingly, controlling and/or determining the extent to which the coating has penetrated into the fabric and/or been absorbed into the fabric is advantageous in optimising the performance of the resulting coated glove.

In some embodiments, the coating is applied to the lined mould at RTP.

Optionally, the wearable item comprises a glove.

In some embodiments, the substrate is applied to a glove mould prior to the coating being applied.

In some embodiments, the coating may be applied such that it covers one or more of the palm, back of hand, fingers, wrist, and knuckles of the glove. In some embodiments, the entire exterior surface of the glove may be coated. It will be appreciated that the external surface of the glove is the surface that is outermost when the glove is worn.

In some embodiments, the coating comprises a first coating and the method further comprises: a. providing a second coating; b. applying the second coating to the substrate.

In some embodiments, providing a second coating comprises preparing a second coating in accordance with the method disclosed herein.

In some embodiments, the first coating may be applied directly to the substrate. In some embodiments, the second coating may be applied to the first coating.

In some embodiments, the second coating may be applied directly to the substrate. In some embodiments, the first coating may be applied to the second coating.

In some embodiments, the first coating and the second coating comprise the same coating formulation and/or are prepared by the same method of preparation. In some embodiments, the first coating and the second coating comprise different coating formulations and/or are prepared by different methods of preparation.

Optionally, after applying the second coating to the substrate, the coated substrate is cured at a temperature of or above 70°C, for example at or above 75°C. For example, at a temperature in the range of from about 75°C to about 95°C.

Optionally, after applying the second coating to the substrate, the coated substrate is cured at a temperature of or above 90°C, for example at a temperature of or above 95°C, for example at a temperature in the range of from about 95°C to about 105°C.

In some embodiments, the substrate coated with the second coating is cured for less than 60 minutes, for example in the range of from about 5 to about 45 minutes, for example in the range of from about 20 to about 40 minutes, for example in the range of from about 25 to about 35 minutes, for example in the range of from about 25 to about 30 minutes, for example in the range of from about 10 to about 30 minutes.

Optionally, prior to curing, the second coating is allowed to gel for a predetermined gelling duration, for example, a predetermined gelling duration in the range of from about 5 minutes to about 20 minutes.

Optionally, a first area of the substrate is coated with the first coating and optionally a second area of the substrate is coated with the second coating. The first area and the second area may be the same or different.

In the embodiment where the substrate is arranged to adopt the form of a glove, the first coating may be arranged to cover, partially or fully, one or more of the following areas: the palm, knuckles, fingers, thumb, back of hand, and/or wrist portion.

In the embodiment where the substrate is arranged to adopt the form of a glove, the second coating may be arranged to cover, partially or fully, one or more of the following areas: the palm, knuckles, fingers, thumb, back of hand, and/or wrist portion.

It will be appreciated that the optional features described may apply to any aspect disclosed herein. All combinations contemplated are not recited explicitly for the sake of brevity.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments will now be described by way of example only with reference to the accompanying figures, in which: Figure 1 illustrates a protective glove to which the coating disclosed herein has been applied; Figure 2 is a schematic cross-section through a portion of the glove of Figure 1; Figure 3 is a flow diagram showing a process for making the coating and coating a substrate with a first coating; Figure 3a is a flow diagram showing an alternative process to that of Figure 3; Figure 4 is a flow diagram showing an alternative process to that of Figure 3; Figure 5 is a flow diagram showing an alternative process to those of Figures 3 and 4; Figure 6 is a flow diagram showing a process for coating the substrate of Figures 3-5, which has been coated with a first coating, with a second coating; and Figure 7 is a graph of the viscosity of coatings 1, 2, 3, 4 and 5 over time, wherein coatings 2, 3, 4 and 5 are in accordance with the present disclosure.

DETAILED DESCRIPTION

With reference to Figure 1, a protective glove is provided as generally indicated at reference numeral 2. The protective glove 2 is configured to provide the wearer with mechanical protection against abrasion.

The glove 2 comprises glove fingers 4, a front palm (not shown), knuckles 42, and wrist 44 and a glove back 6. At one end, a cuff opening (not shown) is provided for introducing the wearer's hand into the glove 2.

As shown in Figure 2, the glove 2 includes a substrate layer 8, a first coating layer 10 and a second coating layer 12. When the glove 2 is worn in the usual manner, the substrate layer 8 is the innermost layer. In some embodiments, the second coating layer 12 is not present.

In the illustrated embodiment, the substrate layer 8 is formed of 100% nylon fabric. In some embodiments, any other suitable substrate material may be used.

A suitable coating for use as the first coating layer 10 will now be described.

The first coating layer 10 is formed of a coating suitable for application to a substrate 8.

The second coating layer 12 is formed of a coating suitable for application to the first coating layer 10. In the illustrated embodiment of Figure 1, both the first coating layer 10 and the second coating layer 12 have the same coating formulation, with the exception that the formulation of the first coating layer 10 includes a white pigment and the formulation of the second coating layer 12 includes a black pigment.

It will be appreciated that the coating disclosed herein may comprise any suitable pigment or no pigment, as desired.

Only one coating will be described below for brevity, however it will be appreciated that this applies to both the first and second coating layers 10, 12.

The coating includes a coating formulation including a waterborne polymer resin component and an additive component.

The coating formulation is an aqueous system and the waterborne polymer resin component includes a polyurea resin. In other words, water is used as the main carrying medium for the polyurea resin. In the way, the need for harmful solvents to be used is avoided.

The additive component includes a binding agent. It is believed that the binding agent provides a structure to the aqueous system, thereby facilitating dispersion of polyurea in the system and enhancing the degree of polymer crosslinking. In this way, the rheology of the aqueous system is modified to provide a coating with improved properties, in particular improved abrasion resistance.

In some embodiments, the binding agent includes one or more of: a water-soluble binding agent soluble at RTP; a hygroscopic binding agent; a water retaining agent; a polar group; a carbonyl, hydroxyl and/or carboxymethyl group; and a polyelectrolyte, for example an anionic polyelectrolyte.

In some embodiments, the binding agent includes one or more of: a polymeric binding agent; and a polysaccharide, for example cellulose.

In some embodiments, the binding agent comprises one or more of: sodium carboxymethyl cellulose (NCMC), carboxymethyl cellulose (CMC), hydroxyl propyl methyl cellulose (HPMC), and polyanionic cellulose (PAC).

In the embodiment of the illustrated embodiment, the binding agent is NCMC.

The coating formulation also includes a polyurethane resin, for example a water-based polyurethane dispersion (WPUD). In other words, the polyurethane resin is dispersed mainly in water.

In some embodiments, the polyurethane resin comprises one or more of: a bio-based polyurethane; an anionic polyurethane resin; a polyester-polyurethane; and a polyether-polyurethane.

Optionally the additive component comprises the WPUD. In some embodiments, the WPUD does not form part of the additive component.

In some embodiments, the coating formulation includes a premix including the binding agent and water. Put another way, in some embodiments the additive component includes a premix.

In some embodiments, the premix includes the polyurethane resin. In alternative embodiments, the polyurethane resin is added to the polyurea resin alongside the premix. In other words, the polyurethane does not form part of the premix.

In some embodiments, the premix is allowed to thicken for a predetermined time, for example in the range of from about 1 day to about 30 days, for example in the range of from about 3 days to about 21 days. For example, the maturation time may be able 7 or 8 days. For example, the maturation time may be in the range of from about 2 weeks to about 3 weeks.

As it thickens, the viscosity of the premix increases. In the illustrated embodiment where the binding agent comprises cellulose, e.g. NCMC, the binding agent swells and disperses in water, thereby increasing the viscosity of the premix.

The thickened premix is then added to the polyurea resin. The premix advantageously modifies the rheology of the aqueous system, providing structure to the aqueous system and enhancing polymer crosslinking. This is achievable, at least in part, due to the increase in viscosity of the premix prior to addition to the polyurea resin.

In alternative embodiments, the binding agent is added directly to the polyurea resin. In other words, no premix is used and the binding agent is added to the polyurea resin without being allowed to thicken in water beforehand. In such examples, the binding agent is mixed with the water present in the water based polyurea resin to form a mixture. This causes the viscosity of the aqueous system to increase. Consequently, the rheology of the aqueous system is improved, providing structure to the aqueous system and enhancing polymer crosslinking.

In some embodiments, additional additives may be included in the coating formulation. For example, the formulation for the first coating layer 10 includes a white coloured pigment, and the formulation for the second coating layer 12 includes a black coloured pigment.

Exemplary processes by which the coating disclosed herein can be made will now be described. It will be appreciated that the coating for the first coating layer 10 and the coating for the second coating layer 12 can be prepared by any of the methods disclosed herein.

With reference to Figure 3, a premix of a binding agent, for example NCMC, a polyurethane resin, for example a WPUD, and water is prepared 14. In some embodiments, the water is provided by the WPUD and/or an NCMC solution. As described above, the premix is allowed to thicken for a predetermined time or until a predetermined viscosity of the premix is reached 16.

Once the premix has matured, it is added to a waterborne polyurea resin to form a coating 18.

The coating is then allowed to thicken 19 further for a predetermined time or until a desired viscosity is reached.

With reference to Figure 3a, a premix of a binding agent, for example NCMC, and water is prepared 15. In other words, no polyurethane resin is included in the premix. In some embodiments, the water is provided by an NCMC solution. As described above, the premix is allowed to thicken for a predetermined time or until a predetermined viscosity of the premix is reached 16.

It will be appreciated that the coating formulation does not include any polyurethane. It will also be appreciated that the embodiment of Figure 3a is the same as that described in relation to Figure 3, with the exception that the coating formulation, in particular the premix, does not include any polyurethane.

Figure 4 illustrates an alternative process in which a premix of a binding agent, for example NCMC, and water is prepared 20. In this embodiment, polyurethane resin, e.g. WPUD, is not added to the premix.

As described above, the premix is allowed to thicken for a predetermined time or until a predetermined viscosity of the premix is reached 22.

Once the premix has thickened, it is added to a waterborne polyurea resin to form a coating 24. The polyurethane resin is added to the waterborne polyurea resin alongside the premix.

The coating is then allowed to thicken 25 further for a predetermined time or until a desired viscosity is reached.

Figure 5 illustrates another alternative process in which a premix is not formed. Instead the binding agent (NCMC) is added directly to the waterborne polyurea resin to form a mixture 26. For example, the binding agent may be added in granule or powder form.

The polyurethane resin is added to the waterborne polyurea resin alongside the binding agent, for example in dry form.

The mixture is then allowed to thicken for a predetermined time or until a predetermined viscosity is reached 28.

In some embodiments, the NCMC and waterborne polyurea resin mixture is allowed to thicken prior to addition of the polyurethane.

In some embodiments, the polyurethane resin is omitted from the coating formulation.

Any additional additives and/or pigments can then be added to the coating formulation.

The first coating layer 10 may be formed of a coating prepared in accordance with the process illustrated in any one of Figures 3, 3a, 4, or 5. Similarly, the second coating layer 12 may be formed of a coating prepared in accordance with the process illustrated in any one of Figures 3, 3a, 4, or 5.

Once the coating is prepared by any of the above-described methods, it can be applied to a substrate, for example to form a wearable item of protective apparel, such as a glove.

As illustrated in Figures 3-5, a mould is provided, for example a glove mould, and a fabric substrate is loaded onto the mould 32. The fabric substrate is formed of 100% nylon fabric. In some embodiments, any other suitable substrate material may be used.

Once the substrate has been loaded onto the mould, the lined mould is heated 34 to a temperature in the range of about 25°C to about 75°C, from example from about 35°C to about 65°C.

In some embodiments, the mould is heated prior to the fabric being loaded onto the mould.

In some embodiments, the mould is not heated prior to loading and/or after loading with fabric.

Once at the desired temperature, the lined mould is dipped into the first coating such that the coating is applied to the fabric substrate 36 to the desired extent. In the embodiment illustrated in Figure 1, the coating 10 is applied such that it covers all of the fingers 4, back of hand 6, palm (not shown), knuckles 42, and wrist 44 of the eventual glove.

In the illustrated embodiment shown in Figure 1, a first coating is applied to the fabric substrate such that it covers the entire exterior surface of the glove.

Once the first coating has been applied as desired, the coated substrate is left to gel 38 at RTP for a gel time in the range of from about 5 minutes to about 20 minutes.

Following gelling, the coated substrate is cured 40 at a cure temperature in the range of from about 75°C to about 105 °C for a cure time in the range of from about 5 minutes to about 35 minutes.

With reference to Figure 6, a second coating is then applied 36a to the first coating layer 10, such that the second coating layer 12 is formed. The second coating is applied on top of the first coating layer 10 such that it covers the exterior surface of the glove down to the wrist 44, i.e. including the fingers and thumb 4, palm (not shown), back of the hand 6 and knuckles 42.

Once the second coating has been applied as desired, the coated substrate is left to gel 38a at RTP for a gel time in the range of from about 10 minutes to about 20 minutes.

Following gelling, the coated substrate is cured 40a at a cure temperature in the range of from about 95°C to about 105 °C for a cure time in the range of from about 25 minutes to about 30 minutes.

The required viscosity of the coating has been found to depend on the particular substrate material used. For example, for a nylon or nylon/spandex mix, it has been found that a viscosity of 400cps provides good results, whereas other fabrics may require a coating viscosity of 1000 to 1250cps in order to produce good results.

With reference to Figure 7, it can be seen that the viscosity of the coating depends, at least on part, on the duration of time after the coating has been mixed with the binding agent and polyurethane, when present, and the manner in which the binding agent and polyurethane are introduced to the polyurea resin, that is either directly or via a premix.

Still with reference to Figure 7, coating 1 is a polyurea resin to which a binding agent and polyurethane have not been added. The viscosity of coating 1 remains between 310 and 320cps, even after 7 days.

Coating 2 is a polyurea resin to which a binding agent and polyurethane has been added as a premix. The binding agent and polyurethane are mixed together as a premix and allowed to thicken for 2-3 weeks. The premix is then added to the polyurea resin to form coating 2. On the first day, coating 2 was found to have a viscosity of 400cps. This increased to 880cps over the course of 7 days.

Coating 3 is a polyurea resin to which a binding agent and polyurethane resin have been added directly. On the first day, coating 3 was found to have a viscosity of 500cps. This increased to 1520cps over the course of 7 days.

Coating 4 is a polyurea resin to which a binding agent has been added as a premix. The binding agent is mixed with water to form a premix and allowed to thicken for 2-3 weeks. The premix is then added to the polyurea resin to form coating 4. No polyurethane resin is present. On the first day, coating 4 was found to have a viscosity of 400cps. This increased to 1350cps over the course of 7 days.

Coating 5 is a polyurea resin to which a binding agent has been added as a premix. The binding agent is mixed with water to form a premix and allowed to thicken for 2-3 weeks. The premix is then added to the polyurea resin. Polyurethane resin is added to the polyurea resin at the same time as the premix to form coating 5. On the first day, coating 5 was found to have a viscosity of 400cps. This increased to 1125cps over the course of 7 days.

Accordingly, the method of preparing the coating disclosed herein, i.e. whether to add the binding agent and polyurethane (when present) directly or via a premix, can be selected based on the substrate to which the coating will be applied, and the viscosity of the coating that produced good results for that particular substrate.

The data used to prepare the graph in Figure 6 is provided in tables 6 and 7 below.

The viscosity figures of Figure 6 were measured at a temperature of 26 to 30°C on a Brookfield viscometer using a number 3 spindle rotating at 20rpm.

Exemplary coating formulations are provided below. The examples herein are provided to facilitate an understanding of the invention. The examples are not intended to limit the scope of the claims.

Example 1

A coating for application to a substrate has the following composition: Percentage dry weight of the overall coating formulation weight NCMC 0.250/0 to 1.0%. For example 0.25, 0.5, 0.75 or 1.0%.

WPUD 0.0°/0 to 7.5%. For example 0.0, 1.0, 2.5, 5.0 or 7.5%. e

The remainder of the composition is made up of 20% Polyurea resin, and water in the case where the NCMC and/or WPUD (when present) are provided in solution. In the case of NCMC and WPUD provided in solution, the NCMC is provided in a solution comprising 5% solid content of NCMC and the WPUD (when present) is provided in a solution comprising 50% solid content of WPUD.

Example 2

A coating for application to a substrate has the following composition: Percentage weight of the overall coating formulation weight Waterborne Polyurea resin (20% solid 91.5 to 99.75% content of polyurea in resin) NCMC 0.25% to 1.0%. For example 0.25, 0.5, 0.75 or 1.0°/0 WPUD 0.0% to 7.5%. For example 0.0, 1.0, 2.5, 5.0 or 7.50/0.

In this example, the NCMC and WPUD (when present) are added directly to the polyurea in powder or granule form.

Example 3

A coating for application to a substrate has the following composition: Percentage weight of the overall coating formulation weight (i.e. wet weight) Waterborne Polyurea resin (20% solid content of polyurea in resin) 65% to 95% NCMC solution (5% solid content of NCMC in solution) 5.00/0 to 20%. For example 5.0%, 10.0%, 15.0% or 20.0%.

WPUD solution (50% solid content of WPUD in solution) 0.0% to 15%. For example 0.0%, 2.0%, 5.0%, 10.0°/0 or 15%.

r::;tie 3 In this example, the NCMC and WPUD (when present) components form a premix, which is matured for 2 to 3 weeks before being added to the waterborne polyurea resin.

Example 4

A coating for application to a substrate has the following composition: Wet Batch Weights Dry Weight of each Percentage of each Chemical Weight (g) OR component in component in (g) OR Dry Parts Wet Parts 1kg of coating formulation dry/cured coating film Waterborne Polyurea resin (200/0 solid content of polyurea in resin) 100 500 833.325 g 78.44% Premix NCMC 2.5 50 83.3325 g 1.960/0 (5% solid content of NCMC in solution) WPUD 25 50 83.3325 g 19.60% (50% solid content of WPUD in solution) Mbhit 4 The premix is matured for 2 to 3 weeks before being added to the waterborne polyurea resin.

It will be understood that 100g of waterborne polyurea resin, having 20% solid content of polyurea, includes 80g of water; 100g of NCMC, having 5% solid content of NCMC, includes 95g of water; and 100g WPUD, having 50% solid content of WPUD, includes 50g of water.

It will be appreciated that in the coating formulation, the batch weights refer to the wet weight of the components. Further, it will be appreciated that in the cured coating, the percentages refer to the proportion of dry components.

Example 5

Batch Weights Wet of each Percentage of each Dry Weight component in component in Weight OR OR Wet 1kg coating dry/cured coating Chemical Dry Parts Parts formulation film Waterborne Polyurea resin a product sold under the name Polyurea WB2000 manufactured by Touch Green Co Ltd and supplied by Hyperclean Technology Co Ltd South Korea 100 500 833.325 g 78.44% Premix NCMC - 2.5 50 83.3325 g 1.96% a product sold under the name Accelerate DS 813 by FMC Biopolymers or a binding agent sold under the name AC-DI-SOL SD711 and manufactured by Dupont.

WPUD - 25 50 83.3325 g 19.60% a WPUD sold under the name Impranil DLP by Covestro or a WPUD sold under the name Hauthane HD-2107 by Hauthaway.

The premix is matured for 2 to 3 weeks before being added to the waterborne polyurea resin.

The WPUD is in dispersion form and it is a 50% WPUD dispersion. Accordingly, per 100 g of WPUD there is 50g of water and 50g of polyurethane ingredients. The NCMC is in powder or granule form and made up to a 5% solution of NCMC. Accordingly, per 100g, there is 95g of water and 5g of NCMC powder or granules.

Accordingly, for 200g of premix, there is 145g of water, 5g of NCMC and 50g of polyurethane solid contents.

Example 6

Three different coatings were prepared and the viscosity of each measured every 24 hours over a period of 7 days. The measured viscosities are provided in Table 6 below. Viscosity was measured at a temperature of 26 to 30°C on a Brookfield viscometer using a number 3 spindle rotating at 20rpm.

Coating 1 comprises a waterborne polyurea resin in accordance with the formulation described in KR20150046992A. In other words, it does not comprise a binding agent or polyurethane resin.

Coatings 2 and 3 are in accordance with embodiments of the present disclosure.

Coating 2 comprises a polyurea resin to which a premix of NCMC and WPUD has been added. The formulation of coating 2 includes 0.5% NCMC (dry weight percentage of overall coating composition) and 5.0% WPUD (dry weight percentage of overall coating composition).

Coating 3 comprises a polyurea resin to which NCMC granules and WPUD has been added.

The formulation of coating 3 includes 1% NCMC and 2.5% WPUD (dry weight percentage of overall coating composition). The NCMC was not added to water prior to addition to the polyurea resin and the WPUD was added to the polyurea resin at the same time as the NCMC.

24 hour period Viscosity (cps) Coating 1 Coating 2 Coating 3 1s' 310 400 500 2nd 315 490 590 3rd 315 650 950 4th 318 740 1150 5th 318 800 1350 6th 320 860 1440 7th 320 880 1520 Tabb. 6 The first 24 hour period means 1 day after the additives are added to the polyurea resin.

When applied to polyester and nylon substrates, Coating 1 was found to provide low protection against abrasion. In this case, abrasion was measured using test method BS EN 388:2016+A1:2018 (clause 6.1). Specifically, the coated substrate was subjected to multiple abrasion cycles or rubs using Klingspor PL31B, Grit 180, as the abradant. Each abrasion cycle was carried out at a pressure of 9.0 ± 0.2 kPa. Under the standard test method, a performance level one equates to test failure between 100-500 abrasion cycles, level 2 equates to between 500-2000 cycles, level 3 equates to between 2000- 7999 cycles, and level 4 equates to 8000 abrasion cycles or above. The substrate to which coating 1 was applied was found to achieve a level 2 on this abrasion test.

Furthermore, Coating 1 was found to be unsuitable for use with fabrics comprising engineered yarns.

Coating 2 was found to provide a more durable coating when applied to a substrate, with enhanced abrasion performance of 7500-9500 cycles (using the test method according to BS EN 388:2016+A1:2018 described above).

Coating 3 was found to give good coating results, especially for fabrics comprising thin gauge cut resistant yarns. Furthermore, the viscosity of coating 3 was found to increase more rapidly than that of coating 2, resulting in a reduced maturation time being required to reach a desired viscosity.

Example 7

Two different coatings were prepared and the viscosity of each measured every 24 hours over a period of 7 days. The measured viscosities are provided in Table 7 below. Viscosity was measured at a temperature of 26 to 30°C on a Brookfield viscometer using a number 3 spindle rotating at 20rpm. The first 24 hour period means 1 day after the additives are added to the polyurea resin.

Coatings 4 and 5 were prepared in accordance with the present disclosure.

In Coating 4, a premix of NCMC in water was prepared. The coating formulation of coating 4 includes 0.5% NCMC (dry weight percentage of overall coating composition). This is prepared as a premix in water such that the premix includes 5% solid content of NCMC in premix solution. No WPUD is present. Once a desired viscosity was reached, the premix was added to the waterborne polyurea resin.

In Coating 5, a premix of NCMC in water was prepared. The coating formulation of coating includes 0.5% NCMC (dry weight percentage of overall coating composition). This is prepared as a premix in water such that the premix includes 5% solid content of NCMC in premix solution. Once a desired viscosity was reached, the premix was added to the waterborne polyurea resin. 5.0% WPUD (dry weight percentage of overall coating composition) was added to the waterborne polyurea resin at the same time as the premix.

24 hour period Viscosity (cps) Coating 4 Coating 5 1st 400 400 2nd 725 500 3rd 850 625 4th 1025 775 5th 1100 900 6th 1225 1000 7th 1350 1125 iable 7 The resulting Coating 4 was found to provide a good coating on polyester, nylon spandex, fabrics comprising cut resistant yarns having a thicker gauge and substrates high in polyester or nylon content. Coating 4 was also found to provide good abrasion performance of 6500-8000 cycles on think liners comprising a significant proportion of polyester or nylon (using the test method according to BS EN 388:2016+A1:2018 described above).

The one or more embodiments are described above by way of example only and it will be appreciated that the variations are possible without departing from the scope of protection afforded by the appended claims. For example, the coating may be applied to any type of wearable item or substrate.

Claims

CLAIMS1. A coating for application to a substrate, wherein the coating comprises a coating formulation comprising a waterborne polymer resin and an additive component, wherein the additive component comprises a binding agent, and wherein the coating formulation comprises an aqueous system.
2. A coating according to claim 1, wherein the waterborne polymer resin comprises a polyurea resin.
3. A coating according to claim 1 or 2, wherein the binding agent is water soluble at room temperature and pressure (RTP).
4. A coating according to any preceding claim, wherein the binding agent comprises a water retaining agent.
5. A coating according to any preceding claim, wherein the binding agent comprises a polar group, for example a carbonyl, hydroxyl and/or carboxymethyl group.
6. A coating according to any preceding claim, wherein the binding agent comprises a polyelectrolyte, for example an anionic polyelectrolyte.
7. A coating according to any preceding claim, wherein the binding agent comprises a polysaccharide, e.g. cellulose.
8. A coating according to any preceding claim wherein the coating formulation, optionally the additive component, further comprises a polyurethane resin.
9. A coating according to claim 8, wherein the polyurethane resin comprises a comprises a water-based polyurethane dispersion (WPUD).
10. A coating according to claim 8 or 9, wherein the polyurethane resin comprises a bio-based polyurethane.
11. A coating according to claim 8, 9 or 10, wherein the polyurethane resin comprises an anionic polyurethane resin.
12. A coating according to any preceding claim, wherein the additive component comprises a premix comprising the binding agent and water.
13. A coating according to claim 12, wherein the premix is allowed to thicken for a predetermined time and/or until the premix has reached a desired viscosity.
14. A coating according to claim 12 or 13 when dependent on any of claims 8 to 11, wherein the premix comprises the polyurethane resin.
15. A coating according to any preceding claim, wherein the substrate comprises a fabric.
16. A coating according to any preceding claim, wherein the coating has a viscosity in the range of from about 400cps to about 1600cps, for example in the range of about 400cps to about 1250cps, for example 600cps, for example 1000cps, for example 1250cps, wherein said viscosity is measured at temperature of 26 to 30°C on a Brookfield viscometer using a number 3 spindle rotating at 20rpm.
17. A coating according to claim 16, wherein the viscosity of the coating is selected based on said substrate.
18. A wearable item of protective apparel comprising a fabric to which the coating of any of claims 1 to 17 has been applied.
19. A wearable item according to claim 18, wherein the wearable item comprises a glove.
20. A method of preparing a coating for application to a substrate, wherein the method comprises: a. providing an additive component comprising a binding agent; b. providing a waterborne polymer resin; and c. introducing the additive component to the waterborne polymer resin; wherein the coating comprises an aqueous system.
21.A method according to claim 20, further comprising providing a polyurethane resin and introducing the polyurethane resin to the waterborne polymer resin.
22. A method according to claim 20 or 21, further comprising the step of introducing water to the binding agent to form a mixture, and wherein the method further comprises allowing the mixture to thicken for a predetermined time and/or until a desired viscosity has been reached.
23. A method according to claim 22, wherein the additive component, comprising the binding agent, is introduced to the waterborne polymer resin, such that the mixture comprises water from the waterborne polymer resin.
24.A method according to claim 23 when dependent on claim 21, wherein polyurethane resin is introduced to the waterborne polymer resin after the mixture has been allowed to thicken.
25. A method according to claim 22, wherein the additive component comprises a premix comprising the binding agent and water, such that the mixture comprises the premix.
26. A method according to claim 25, wherein the premix is allowed to thicken prior to being introduced to the waterborne polymer resin.
27. A method according to claim 25 or 26 when dependent on claim 21, wherein the premix further comprises the polyurethane resin.
28. A method according to any of claims 25, 26 or 27 when dependent on claim 21, wherein the polyurethane resin is introduced to the waterborne polymer resin along with the additive component.
29. A method according to any of claims 20 to 28, wherein, after addition of the binding agent and optionally the polyurethane, the coating is allowed to thicken until a desired viscosity is reached, for example until the coating has a viscosity in the range of from about 400cps to about 1600cps, for example in the range of about 400cps to about 1250cps, for example 600cps, for example 1000cps, for example 1250cps, wherein said viscosity is measured at temperature of 26 to 30°C on a Brookfield viscometer using a number 3 spindle rotating at 20rpm.
30. A coating according to claim 29, wherein the desired viscosity of the coating is selected based on said substrate.
31.A method of making a wearable item of protective apparel, the method comprising: a. preparing a coating in accordance with the method of any of claims 20 to 30; b. providing a substrate; c. applying the coating to the substrate; wherein the substrate is arranged to adopt the form of the wearable item before or after the coating is applied to the substrate.
32. A method according to claim 31, wherein, after applying the coating to the substrate, the coated substrate is cured at a temperature above 90°C, for example at a temperature above 95°C, for example at a temperature in the range of from about 95°C to about 105°C.
33. A method according to claim 32, wherein, prior to curing, the coating is allowed to gel for a predetermined gelling duration, for example, a predetermined gelling duration in the range of from about 5 minutes to about 20 minutes.
34. A method according to any of claims 31 to 33, wherein the substrate is heated prior to the coating being applied.
35. A method according to any of claims 31 to 34, wherein the wearable item comprises a glove.