WO2020021316A1

WO2020021316A1 - Composition for forming a re-stylizable hairstyling coating

Info

Publication number: WO2020021316A1
Application number: PCT/IB2018/055625
Authority: WO
Inventors: Manel Torres
Original assignee: Manel Torres
Priority date: 2018-07-27
Filing date: 2018-07-27
Publication date: 2020-01-30

Abstract

The present invention refers to a composition for forming a hair coating by spraying onto a supporting surface, the composition comprising a binder and a diluent, wherein the diluent may be one or more carriers in a single-phase composition or in a dual-phase composition, wherein the binder is a waterborne emulsion copolymer with small particle size, stabilized by means of a biodegradable surfactant system, and containing fibres. In addition, the invention refers to an apparatus comprising a container containing the composition of the invention, to a coating produced by spraying the composition of the invention, to an article comprising the coating of the invention, to a method for producing coatings by spraying the composition of the invention onto a supporting surface, e.g. a human head or animal or another substrate, and to the use of the composition of the invention for forming a coating.

Description

COMPOSITION FOR FORMING A RE-STYLIZABLE HAIRSTYLING

COATING

Field of the invention

This invention relates to hair styling products, i.e. for changing the hair colour, concealing hair loss, ornamenting hair, and hair conditioning. In particular, the invention refers to a hair styling composition for forming a re- stylable hairstyling coating, and also to an apparatus comprising a container containing the composition of the invention, to a coating produced by spraying the composition of the invention, to an article comprising the coating of the invention, to a method for producing coatings by spraying the composition of the invention onto a supporting surface, e.g. a human head or animal or another substrate, and to the use of the composition of the invention for forming a coating.

Background

People frequently seek to style their scalp or facial hair, for example to provide a certain hairstyle for their hair or, in other cases, to style their eyebrows or, in the case of male persons, to style their beards, moustaches and/or sideburns, by decorating them. Once styled, it is desirable that the hair remains set or held in the styled position, or preserves its decorated condition, and further, that the hair can be easily re-styled when the initial hair style has been disturbed, in a second or further hairstyle, while retaining a non-sticky feel.

As synthetic resins to be used in cosmetics, polymers such as vinyl pyrrolidone resins, and vinyl methyl ether resins, of varying ionicity such as anionic, cationic, non-ionic or amphoteric ionicity, are widely known. These synthetic resins are used for retaining hair style or protecting the skin, utilizing their film-forming ability. However, undesirable characteristics are often observed, in that the resulting film may be too hard or sticky, depending on the resin used.

Aerosol hair compositions conventionally used for hair styling usually set the hair by making use of the fixing force of a hair styling polymer. However, once set in this way the hair cannot be re-styled and those people who used aerosol hair styling sprays are sometimes dissatisfied with a stiff or hard feel of the hair treated therewith.

Pressure Sensitive Adhesives (PSAs) have been used before in hair care compositions as described in US5166276, EP408311 , EP412707 and EP412704. Nevertheless, these PSAs tend to hydrolyse in aqueous and hydroalcoholic hair care products.

Acrylic Pressure Sensitive Adhesives (PSAs) as described in W02007/071308 are random copolymers comprising an acrylic group having a side-chain with at least 4 carbons (e.g. n-butyl acrylate or 2-ethylhexyl acrylate) and having a low glass transition temperature Tg, a short side-chain acrylic such as methyl acrylate to adjust the Tg, and acrylic acid to improved adhesion and optimise elongation properties (i.e., their mechanical response to deformation in uniaxial extension). Small molecule additives such as tackifiers may be included to adjust the Tg and optimise dissipative properties but are not essential.

US2013/0344006 A1 discloses aqueous hair treatment compositions with improved re-styling benefits comprising acrylic PSAs (e.g. 98% butyl acrylate (BA), 2% methyl acrylic acid (MAA), Roderm MD-5800 ex Rohm and Haas).

US 9,023,332 B2 discloses an aqueous hair treatment composition with improved re-styling benefits, consisting of 0.2 to 5 wt % of the total composition of polyacrylate crosspolymer-6, 98% butyl acrylate (BA), 2% methyl acrylic acid (MAA)) (Roderm MD-5800 ex Rohm and Haas), and water.

However, these aqueous formulations are un-stable (i.e. agglomerated particles within composition or congealed product) where polyacrylate crosspolymer-6 are not used. US 9,186,313 B2 discloses a hair treatment composition in the form of cream, gel or wax with improved sensory feel re-styling benefits (i.e. makes the hair soft when dry and can re-style hair until next wash), comprising an oligosaccharide which is maltotriose and/or maltotetraose; and an acrylic PSA comprising a random copolymer of n-butyl acrylate (BA) and methyl acrylic acid (MAA)), having a weight ratio of MAA: BA from 1.9:98.1 to 4.0:96.

There is therefore a demand for alternative compositions for forming a hairstyling product by spraying onto a human head or animal or another substrate, comprising an acrylic PSA, wherein, after the hair has been styled and sprayed, it can be easily brushed and styled in a different way, while holding the hair in the new style. There is also a need for hair styling methods superior in re-styling performance.

Summary of the invention

In a first aspect, the invention provides a composition for forming a hairstyling product by spraying onto a human head or animal or another substrate, the composition comprising a binder, fibres and a diluent, wherein the diluent may comprise one or more carriers in a single-phase composition or in a dual-phase composition, and wherein the binder is a waterborne emulsion copolymer with small particle size, stabilized by means of a biodegradable surfactant system.

A second aspect of this invention is an apparatus comprising a container containing the composition of the present invention and a device capable of producing a spray of the composition from the container.

A third aspect of this invention is a coating for the hair produced by spraying a composition of the present invention, wherein the coating comprises the binders in solid form, and may include natural or synthetic fibres enveloped by the binders.

A fourth aspect of this invention is an article comprising a coating for the hair according to the third aspect of this invention. A fifth aspect of this invention is a method for producing a coating for the hair comprising: a) providing a container capable of producing a spray containing the composition according to the present invention, and

b) spraying the composition onto a human head, animal or other substrate thereby forming a coating on the supporting surface.

A sixth aspect of this invention is a use of the composition according to the present invention for forming a coating.

Brief description of the drawings Figure 1 and 2 illustrate the shape evolution after VO V1 V2 for one hair tress, by using Sunsilk Conditioner - Perfect Straight Conditioner (Hindustan Unilever Limited).

Figure 3 and 4 illustrate the shape evolution after VO V1 V2 for one hair tress, by using the hairspray of the present invention. Figure 5 illustrates the volume at VO is similar for both products.

Moreover, after V1 and V2 the tresses treated with Sunsilk conditioner swell more than those treated with the hairspray of the present invention. Globally the hair tresses treated with the hairspray of the invention generate much less volume than Sunsilk. The restyling index is 5 times higher for the hairspray of the present invention than for Sunsilk conditioner (respectively 49.3 vs 10.2).

Detail description of the invention

According to the first aspect, the invention particularly relates to a composition for forming a hair coating by spraying onto a supporting surface, the composition comprising a binder, fibres and a diluent, wherein the diluent may comprise one or more carriers in a single-phase composition or in a dual- phase composition, wherein the binder is a waterborne emulsion copolymer with small particle size, stabilized by means of a surfactant system. In an embodiment, the binder in the composition of this first aspect is a waterborne emulsion copolymer with a particle size ranges for 50 to 250 nm, stabilized by means of a combination of anionic and non-ionic surfactant, and wherein the fibres are microcrystalline cellulose.

The fibres may be selected from the group consisting of microcrystalline cellulose, cotton fibres or cotton flock, another cellulose fibres, wool fibres, silk fibres, Jute fibres or jute flock, acrylic fibre flock (e.g. polyacrylonitrile flock), nylon fibres, viscose flock, cashmere fibres, linen fibres, seaweed cellulose fibres, ramie cellulose fibres, mink fur fibres, rabbit hair fibres, aramid fibres, chitosan fibres, other natural fibres, Carbon fibres, Glass fibres, Metallic fibres (e.g., steel, copper, silver etc.), ceramic fibres, or alpaca fibres.

The fibres should be of a certain minimum length. Generally, at least 80% of the fibres have a length of at least 0.02 mm. Preferably, at least 90%, more preferably at least 95% and most preferably, substantially all the fibres in the composition have a length of at least 0.02 mm.

The fibres should not be too long since a composition comprising long fibres cannot be sprayed easily because the fibres can block a small nozzle. Generally, at least 80% (by weight) of the fibres have a length not more than 10 mm, preferably not more than 5 mm, more preferably not more than 1 mm, still more preferably not more than 0.5 mm, even more preferably not more than 0.25 mm, most preferably not more than 0.15 mm. Preferably, at least 90%, more preferably at least 95% and most preferably substantially all the fibres have a length not more than 10 mm, preferably not more than 5 mm, more preferably not more than 1 mm, still more preferably not more than 0.5 mm, even more preferably not more than 0.25 mm, more preferably not more than 0.15 mm, and most preferably not more than 0.02 mm. Preferably, the fibres are milled before use to a length of approximately 0.02 - 0.15 mm.

Preferably, the fibres in the composition is in a concentration of about

0.12 wt%. The diluent in the composition of the invention may comprise one or more carriers in a single-phase composition or in a dual-phase composition.

If present in a single-phase composition, e.g. one liquid phase, a first carrier may be a liquefied gas propellant or a solvent that can readily be vaporized, and a second carrier may be a liquid solvent.

If the diluent in the composition of the invention is present in a dual- phase composition, the diluent may comprise a compressed gas propellant as a first carrier and a liquid solvent as a second carrier. Thus, the diluent in the composition of the invention may comprise a propellant and/or a solvent.

Either in a single-phase composition or in a dual-phase composition, the diluent in the composition of the invention may comprise as first carrier a liquefied gas propellant selected from the group consisting of liquefied petroleum gas, dimethyl ether, trans-1 -Chloro-3,3,3-trifluoropropene (commercially known as Solstice Performance Fluid) and trans-1 ,3,3,3- tetrafluoropropene (commercially known as Solstice propellant), or a compressed gas propellant selected from compressed air, nitrogen or carbon dioxide; and mixtures thereof. Preferably, the first carrier can be a propellant such as dimethyl ether.

Either in a single-phase composition or in a dual-phase composition, the diluent in the composition of the invention may comprise a propellant as first carrier which makes up between 10 and 99% of the composition, preferably between 40 and 99%, more preferably between 70 and 99% of the composition by weight, based on the total weight of the composition.

Either in a single-phase composition or in a dual-phase composition, the diluent in the composition of the invention may comprise a solvent as second carrier that may be selected from alcohols, ethers, ketones and hydrofluoroolefins. Preferably, the solvent may be an alcohol selected from ethanol, 1 -propanol or 2-propanol.

The diluent in the composition of the invention may comprise a first carrier in which the binder is dissolved or emulsified and a second carrier whose boiling point is at least 40 °C and is higher than the boiling point of the first carrier, and preferably the second carrier is selected from ethanol, 1- propanol or 2-propanol.

Usually, substantially all the propellant and the solvent evaporate before the composition reaches the substrate or the supporting surface, thereby forming a structural coating on the substrate or on the supporting surface.

The diluent in the composition of the invention may comprise a first carrier and a second carrier, wherein the first carrier is more volatile than the second carrier. The second carrier becomes incorporated in the fabric as a liquid therefore must be a liquid at temperatures up to 40 °C. The second carrier has a higher boiling point than the first carrier. Preferably the boiling point of the second carrier is at least 30 °C higher than the boiling point of the first carrier, more preferably at least 50 °C higher, most preferably at least 60 °C higher.

The relative volatilities of the first carrier and the second carrier reflect the purpose of each of these components. The first carrier may be a compressed gas or a liquid in the composition before spraying. The first carrier, however, may have a boiling point below room temperature and to maintain its compressed gas or liquid state, the composition can be stored at a high pressure. In any case, the composition is stored in a pressurized container such as an aerosol can under a pressure of above 1 and less than 20 atmospheres.

The purpose of the first carrier is to dissolve or emulsify the binders in the composition so that the composition can be sprayed. If the binders were not soluble or emulsified in the composition, when sprayed, the composition would not deposit a coherent layer of coating on substrates. Most of the first carrier evaporates before the composition reaches the substrate surface and the coating is formed. Once the first carrier has evaporated in the spraying process, the binders remain in solid form to bind the fibres together to form a coating. It is advantageous to have a first carrier which is a propellant will have a further function of propelling the spray. When the composition comprises a propellant, the composition should be stored in a pressurized container. When an opening is made in the container (usually at a nozzle for spraying) the propellant, with the rest of the composition, leaves the container in a form of a spray because of the energy stored in the pressurized propellant.

In contrast, the purpose of the second carrier is that it should not substantially evaporate during spraying and should be deposited on the substrate with the solids in the composition of the invention. In a preferred embodiment, the second carrier can be selected from the group consisting of ketones, alcohols, esters and ethers. More preferably, the second carrier may be selected from the group consisting of acetone, ethanol, polyhydric alcohols, glycol ethers, and mixtures thereof. Suitable polyhydric alcohols include ethylene glycol, propylene glycol, isoprene glycol, and dipropylene glycol, glycerol, 1 ,3-butylene glycol, sorbitol, diethylene glycol, monoethyl ether and mixtures thereof.

The binder in the composition of the invention is a waterborne emulsion copolymer with small particle size, stabilized by means of a surfactant system. The surfactant system is preferably biodegradable. A combination of anionic and non-ionic surfactant may be used.

The binder may be an acrylic emulsion copolymer. Preferably, the binder is a combination of methyl methacrylate and 2-ethylhexylacrylate (30/70 - 70/30 monomer parts), wherein the monomers are randomly arranged along the chain (i.e. BC 4365). However, the composition of the invention may comprise additional binders, such as ethylene-vinyl acetate copolymer and/or polyvinyl acetate.

For the purposes of the present invention,“small particle size” means a particle size ranges for 50 nm to 250 nm, preferably for 110 nm to 150 nm, and with an average size of 130 nm.

For the purposes of the present invention, “waterborne emulsion polymers” are suspensions of small polymer droplets which are stabilized by emulsifiers in water. If the polymerization occurs in the droplets formed by raw materials, the emulsion is called “primary emulsion”. If the solution of a solvent-borne polymer is emulsified in water, then it is called “secondary emulsion”. Suitable waterborne acrylic sensitive pressure adhesives in the present invention includes e.g. product BC4365 which is a hydrophobic acrylic consisting in a combination of methyl methacrylate and 2-ethylhexylacrylate (30/70 - 70/30 monomer parts), wherein the monomers are randomly arranged along the chain. This hydrophobic acrylic contains 50% of solids, a viscosity of less than 2500 mPa.s, a pH value between 7 and 8, and a correlation between MFFT (Minimum Film Formation Temperature MFFT) and Tg (glass transition temperature) of 18/20 °C.

Furthermore, the composition of the invention may optionally incorporate functional additive substances affecting the properties of the hair styling product, such as: viscoelastic polymers like hypromellose (HPMC), thermosetting polymers like polyurethane diol, waxes, oils, conditioners, perfumes, resins, pigments, dyes, oleophilic or hydrophilic agents, surfactants, hydrogels, or anti-microbial agents.

In the second aspect, the invention is an apparatus comprising a container containing the composition of the present invention and a device capable of producing a spray of the composition from the container.

The container of the apparatus of the present invention is at a pressure of above 1 and up to 20 atmospheres. Preferably the pressure within the container is between 1 and 20 atmospheres, more preferably between 3 and 15 atmospheres, and more preferably between 5 and 10 atmospheres depending on the propellant used.

The container of the apparatus of the invention is an aerosol can. By “aerosol can” we mean a metal container of the type commonly used to store pressurised products e.g. hair spray or deodorant. The device capable of producing a spray of the apparatus of the present invention has a nozzle with an internal diameter of 0.05 to 2 mm, more preferably 0.1 to 1 mm.

According to the third aspect, the invention is a coating for the hair produced by spraying a composition of the present invention, wherein the coating comprises the binder(s) of the invention in solid form, and include fibres enveloped by the waterborne emulsion copolymer with a small particle size, stabilized by means of a surfactant system, and if present, the other binders, such as e.g. ethylene-vinyl acetate copolymer and/or polyvinyl acetate.

Preferably, the coating for the hair comprises a combination of methyl methacrylate and 2-ethylhexylacrylate (30/70 - 70/30 monomer parts), wherein the monomers are randomly arranged along the chain with a small particle size, stabilized by means of a combination of anionic and non-ionic surfactant.

According to the fourth aspect, the invention is an article comprising a coating for the hair according to the third aspect of this invention. The article may be supported by a substrate, e.g. human or animal hair or another substrate, such as a wig.

The fifth aspect of this invention is a method for producing a solid coating for the hair comprising the steps of: a) providing a container capable of producing a spray containing the composition according to the present invention, and

b) spraying the composition onto a supporting surface, such as a human head, animal or other substrate, e.g. a wig, thereby forming a coating on the supporting surface.

Preferably, the surface to be coated is human or animal hair, such that hair may be styled using a sprayable composition of the invention. For example, after spraying of the composition onto human hair, the hair may be styled before evaporation of the volatile components occurs. This leads to strong hold of the hairstyle that has been created while imparting the ability for the hair to be easily brushed and re-styled in a different way and retaining hold upon the hair in the new style.

Step a) of the method according to the present invention involves pressurizing the container above 1 and 20 atmospheres, preferably between 3 and 15 atmospheres, more preferably between 5 and 10 atmospheres, depending on the propellant used.

The spray formed in step b) of the method according to the present invention is a fine spray with droplet size less than 500 micron.

In another embodiment of this fifth aspect of the invention, the distance between a spray point on the container and the supporting surface is about 5 to 100 cm, preferably 10 to 70 cm, and more preferably 15 to 50 cm.

In the context of any method of spraying the coating for the hair (for example with an aerosol can), the binders and the fibres are present in solid form in the coating produced and give the material characteristics of:

• stiffness, in that the material that provides support for the hair, maintaining the shape of hair styles;

• transparency or opacity, in that the material forms a transparent or opaque coating for the hair as desired, for colouring or styling purposes.

• the ability to be remoulded, in that unlike conventional hair sprays, the hair can be brushed to a new shape and the spray holds the hair in the re-styled form.

The sixth aspect of this invention is a use of the composition according to the present invention for forming a coating comprising the binder in solid form and the fibres bound by the binder.

The following examples illustrate the best method known to the applicant for carrying out the invention. In addition, they exemplify the industrial application of the invention and are provided for illustrating the invention and not so limiting the scope of the claims. Examples

Some embodiments and applications of the invention will now be described by example.

Example 1 : A first hairspray composition of the invention (M1007).

Example 2: A second hairspray composition of the invention (M1018).

Example 3: Evaluation the volume of hair tresses and calculation of the re styling index.

Study Description

The objective of this study was to evaluate the volume of hair tresses with a Bolero device:

(i) after iron straightening and treatment;

(ii) after 30 minutes at 80%HR; and

(iii) after restyling with combing and fingers.

And to calculate an index of restyling with the volume measurement.

The tested products were a hairspray of the present invention (e.g. M1007) and the Sunsilk Conditioner - Perfect Straight Conditioner (Hindustan Unilever Limited). The hair tresses used were wavy, type III, Brazilian, 20 cm length; 2g, batch SP170714-01.

The application of the conditioner was made on each hair tress individually. For each tress (2 g) 0.8 g of the product was weighed into a PP watch glass of 80 mm diameter. The hair tress is slightly rolled up on itself and the application is done in the watch glass. We gently massage the hair (6 times) for 30 seconds and is left to stand for 1 minute. Then the tress is combed, before being rinsed with water at 35 ° C for 30 seconds. The hair is then detangled and dried with a salon hairdryer. Before any iron treatment the hair is all dried. The bottle is positioned vertically at 20 cm of the hair tress. The spraying time is 5 seconds. We rotate the hair tress on itself to have a homogenous coating during the vaporization. The hair tress is attached to a support at the root. The iron is heated at 230°C. A comb guides the hair tress during the straightening. The iron is applied 5 times from root to tips. The tresses were restyled by combing 5 times and squeezing between fingers and thumb and running over the tress 5 times.

The measurement of hair volume and fly-away/frizz is done with a device designed by Bossa Nova Technologies, called Bolero. The set-up consists of a digital camera, a 360° rotation stage (moving support for hair tresses) and a LED back panel. More precisely, this device acquires 36 on- the-fly pictures of the tress, every 10° step. The motorized stage moves slowly over a 360° range, so that the hair swatch has no deformation (no twist, wind, or dynamic movement) when the picture is snapped. On each of the 36 raw images, an algorithm separates the bulk area from the frizzy parts, (fly away fibers). The 3D volume of the hair bulk is reconstructed from the 36 bulk images, and the average frizz is estimated. The algorithm can also calculate the hair density, adjusts automatically the threshold to separate the surface (cm²) of both the bulk and the fly-away fibers. It can display the spatial variation the surface and perimeter of the bulk’s cross section from the root to the tip of the tress. Three (3) parameters were calculated taking in account the 36 positions of the tress every 10 degrees. The 3 parameters are the following:

• The bulk volume (in cm3), corresponds to the area which show the highest hair density

• The fly away frizz (FAF in cm3), represents the independent hair which is outside the bulk.

• The total volume (in cm3), which is the sum of the bulk and frizz (TOT VOL = BULK + FAF).

Results

The table below shows the Total Volume averaged on 6 hair tresses for the both tested products and the restyling index. The calculation of this index is done by the following equation: Restyling Index = (V1-V2)x100/(V1-V0)

Wherein:

VO = Volume after straightening

V1 = Volume after straightening + 30m in at 80% humidity

V2 = Volume after straightening + 30min at 80% humidity + restyling with fingers and comb.

Table 1. Results (Volume and restyling Index)

The volume at VO is similar for both products. Moreover, after V1 and V2 the tresses treated with Sunsilk conditioner swell more than those treated with hairspray of the present invention. Globally the hair tresses treated with the hairspray of the present invention generate much less volume than Sunsilk. The restyling index is 5 times higher for hairspray of the present invention than for Sunsilk conditioner (respectively 49.3 vs 10.2).

Statistical analysis was performed with SPSS version 20.0 according to the following criteria:

• Normality and Homogeneity are verified for a risk a of 1 %.

• Tests are computed with a risk a of 5%.

• The statistical tests (Student Test - ANOVA) are carried out with an alpha risk of 5% The statistical results show that the hair volume generated by the 2 products after iron straightening (VO) is not significantly different. Nevertheless, the volume generated by the hairspray of the present invention after V1 and V2 is significantly lower than Sunsilk.

Furthermore, the volume at VO, V1 and V2 generated by the hairspray of the present invention is not significantly different. Therefore, the humidity doesn’t impact the tresses treated with the hairspray of the present invention significantly. The restyling index is 5 times higher for the hairspray of the present invention than Sunsilk conditioner (respectively 49.3% - 10.2%).

Claims

1. A composition for forming a hair coating by spraying onto a supporting surface, the composition comprising a binder, fibres and a diluent, wherein the binder is a waterborne emulsion copolymer with a particle size ranges for 50 to 250 nm, stabilized by means of a combination of anionic and non-ionic surfactant; wherein the fibres are microcrystalline cellulose; and wherein the diluent may have one or more carriers in a single-phase composition or in a dual-phase composition.

2. The composition according to claim 1 , wherein the binder is a methyl methacrylate and 2-ethylhexylacrylate (30/70 - 70/30 monomer parts) copolymer, wherein the monomers are randomly arranged along the chain.

3. The composition according to claim 1 or 2, wherein the diluent comprises a propellant and/or a solvent.

4. The composition according to claim 3, wherein the propellant is selected from the group consisting of liquefied petroleum gas, dimethyl ether or carbon dioxide, trans-1 -Chloro-3,3,3-trifluoropropene (Solstice Performance Fluid), trans-1 ,3,3,3-tetrafluoropropene (Solstice propellant) and mixtures thereof.

5. The composition according to the claim 3 or 4, wherein the propellant makes up between 10 and 99% of the composition, preferably between 40 and 99%, more preferably between 70 and 99% of the composition by weight, based on the total weight of the composition.

6. The composition according to the claim 3, 4 or 5, wherein the solvent is selected from alcohols, ethers, ketones and hydrofluoroolefins.

7. The composition according to the claim 3, 4, 5 or 6, wherein the solvent is an alcohol selected from ethanol, 1 -propanol or 2-propanol.

8. The composition according to claim 1 , wherein the diluent comprises a first carrier in which the binder is dissolved or emulsified and a second carrier whose boiling point is at least 40 °C and is higher than the boiling point of the first carrier, and wherein the second carrier is selected from ethanol, 1 -propanol or 2-propanol.

9. An apparatus comprising a container containing the composition according to any preceding claim and a device capable of producing a spray of the composition from the container.

10. The apparatus according to claim 9, wherein the container is at a pressure of above 1 and up to 20 atmospheres.

11. The apparatus according to claim 9 or 10, wherein the pressure within the container is between 3 and 15 atmospheres, and more preferably between 5 and 10 atmospheres.

12. The apparatus according to claim 9, 10 or 11 , wherein the device capable of producing a spray has a nozzle with an internal diameter of 0.05 to 2 mm.

13. The apparatus according to claims 9, 10, 11 or 12, wherein the container is an aerosol can.

14. A coating produced by spraying a composition according to any of claims 1 to 8, wherein the coating comprises the binder in solid form and the fibres bound by the binder.

15. An article comprising the coating according to claim 14.

16. A method for producing a solid coating comprising the steps of:

a) providing a container containing a composition according to any of the claims 1 to 8, which can produce a spray of the composition and; b) spraying the composition onto a supporting surface.

17. The method according to claim 16, wherein step a) involves pressurizing the container above 1 and 20 atmospheres, preferably between 3 and 15 atmospheres, and more preferably between 5 and 10 atmospheres.

18. The method according to claim 16 or 17, wherein the spray formed in step b) is a fine spray with droplet size less than 500 pm.

19. The method according to claim 16, 17 or 18, wherein the distance between a spray point on the container and the supporting surface is 5 to 100 cm, preferably 10 to 70 cm, and more preferably 15 to 50 cm.

20. Use of the composition according to any of claims 1 to 8 for forming a coating comprising the binder in solid form and the fibres bound by the binder.