WO2025061352A1

WO2025061352A1 - Process for preparing a cosmetic composition comprising a pulverulent phase and a film-forming polymer solubilized in a volatile solvent; and pigment formulation.

Info

Publication number: WO2025061352A1
Application number: PCT/EP2024/071107
Authority: WO
Inventors: Guillaume Kergosien
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2023-09-20
Filing date: 2024-07-25
Publication date: 2025-03-27
Anticipated expiration: 2026-03-20
Also published as: FR3152981A1

Abstract

The present invention relates to a process for preparing a composition, notably for coating keratin materials, more particularly for making up and/or caring for keratin materials, such as the skin, notably comprising a physiologically acceptable medium and containing at least: a) a pulverulent phase, and b) at least one volatile solvent, c) at least one film-forming polymer in solubilized form in said volatile solvent, comprising at least one step of milling said film-forming polymer in solid form with at least one portion of the pulverulent phase.

Description

Process for preparing a cosmetic composition comprising a pulverulent phase and a film-forming polymer solubilized in a volatile solvent; and pigment formulation.

The present invention aims to provide, for the field of caring for and/or making up keratin materials and in particular the skin, a new process for preparing a composition comprising a pulverulent phase and at least one film-forming polymer solubilized in at least one volatile solvent.

Cosmetic compositions, for example foundations, are commonly used to give the skin an aesthetic colour, but also to enhance the beauty of uneven skin, by making it possible to hide marks and dyschromias, to reduce the visibility of relief imperfections such as pores and wrinkles, and to conceal spots and acne marks. In this regard, coverage, colour and obtaining a natural finish are the main properties that are desired. To obtain this effect, the compositions generally contain a pulverulent phase comprising particulate colorants and optionally fillers.

For several years, consumers have been searching for compositions which provide a good wear property of the care and/or makeup effect over time in order to be able to avoid having to re-apply the composition too often.

One of the solutions proposed by the prior art for obtaining a good wear property is the use of at least one film-forming polymer which allows the composition, once applied, to form, after drying, a more cohesive, adhesive and persistent film on the support. In this case, said film-forming polymer may be directly solubilized in a volatile solvent with stirring during the manufacture of the care and/or makeup composition. This preparation method has the drawback of taking a long time for complete solubilization of said film-forming polymer. Another solution consists in using the film-forming polymer in a form pre-solubilized in a volatile solvent in order to convey said film-forming polymer. This preparation method is restrictive since it involves either an additional preparation time or else leads to the difficulty of finding a film-forming polymer in a pre-solubilized form that is suitable for the composition and which is commercially available from polymer manufacturers and suppliers. In this case, there is the added constraint of also finding a volatile solvent suitable for the composition. This may necessitate having to order and test various reference pre-solubilized film-forming polymers in different solvents to suit the compositions manufactured.

There thus remains a need to find a new process for preparing a composition for caring for and/or making up keratin materials comprising a pulverulent phase and at least one film-forming polymer solubilized in at least one volatile solvent which does not exhibit the abovementioned drawbacks or constraints.

The applicant has discovered, surprisingly, that this objective was achieved with a process for preparing a composition, notably for coating keratin materials, more particularly for making up and/or caring for keratin materials, such as the skin, notably comprising a physiologically acceptable medium and containing at least:

a) a pulverulent phase, and

b) at least one volatile solvent,

c) at least one film-forming polymer in solubilized form in said volatile solvent, comprising at least one step of milling said film-forming polymer in solid form with at least one portion of the pulverulent phase, notably the particulate colorants present in the composition.

This discovery forms the basis of the invention.

The present invention thus relates to a process for preparing a composition, notably for coating keratin materials, more particularly for making up and/or caring for keratin materials, such as the skin, notably comprising a physiologically acceptable medium and containing at least:

a) a pulverulent phase, and

b) at least one volatile solvent,

Another subject of the invention relates to a composition that can be obtained by said preparation process.

According to one particular form, the invention also relates to the process of manufacturing a composition as defined previously containing at least one or more particulate colorant(s), comprising at least the following steps:

a) preparing a particulate colorant formulation comprising said particulate colorant(s) and at least one film-forming polymer in solid form by milling said film-forming polymer with a portion or all of the particulate colorant(s); and

b) mixing said volatile solvent with the particulate colorant formulation thus obtained.

Another subject of the invention also relates to a particulate colorant formulation that can be obtained by step a) of the process as defined previously.

Another subject of the invention also relates to a composition for caring for and/or making up keratin materials comprising at least the particulate colorant formulation as defined previously.

The invention also relates to a process for coating keratin materials, more particularly for caring for and/or making up keratin materials such as the skin, characterized in that it comprises the application to the keratin materials of a composition as defined previously.

Definitions

In the context of the present invention, the term “keratin material” is understood in particular to mean the skin (body, face, area around the eyes, cheeks, eyelids), the lips and/or keratin fibres such as the eyelashes and eyebrows.

The term “physiologically acceptable” is understood to mean compatible with the skin, the lips and/or keratin fibres such as the eyelashes and eyebrows, which has a pleasant colour, odour and feel and which does not generate unacceptable discomfort (tingling, tautness) which is likely to discourage the consumer from using this composition.

Pulverulent phase

A composition according to the invention preferably has a content of pulverulent phase of greater than or equal to 5% by weight, in particular greater than or equal to 10% by weight, more particularly ranging from 12% to 40% by weight, relative to the total weight of the composition.

The pulverulent phase preferably comprises at least one filler and/or at least one particulate colorant.

Fillers

The term “fillers” should be understood as meaning colourless or white solid particles of any shape, which are in a form that is insoluble and dispersed in the medium of the composition. Mineral or organic in nature, they make it possible to confer softness, mattness and uniformity of makeup on the composition.

The filler(s) used in the composition of the invention is (are) chosen from mineral fillers, organic fillers and mixtures thereof.

The filler(s) used in the composition of the invention is (are) present in the composition of the invention preferably in a content ranging from 0% to 15% by weight, more preferentially from 1% to 10% by weight relative to the total weight of the composition.

The filler(s) used in the composition of the invention is (are) present preferably in a content ranging from 0% to 50% by weight, more preferentially from 10% to 40% by weight relative to the total weight of the pulverulent phase.

Among the mineral fillers that may be used in the compositions according to the invention, mention may be made of talcs, natural micas, synthetic micas such as fluorphlogopite, silica, magnesium aluminium silicates, kaolin, bentone, calcium carbonate, magnesium hydrogen carbonate, hydroxyapatite, boron nitride, hollow silica microspheres (Silica Beads from Maprecos), silica-based fillers, for instance Aerosil 200® or Aerosil 300®; Sunsphere H-33® and Sunsphere H-51® sold by Asahi Glass; Chemicelen® sold by Asahi Chemical; composites of silica and of titanium dioxide, for instance the TSG® series sold by Nippon Sheet Glass, perlite powders, and mixtures thereof.

Among the organic fillers that can be used in the compositions according to the invention, mention may be made of polyamide powders (Nylon® Orgasol from Atochem), poly-β-alanine and polyethylene powders, polytetrafluoroethylene (Teflon®) powders, lauroyl-lysine, starches such as the native corn starch having the INCI name: Zea mays (corn) starch, modified starches such as aluminium starch octenylsuccinate (Dry Flo), metal soaps derived from organic carboxylic acids containing from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, for example, zinc, magnesium or lithium stearate, zinc laurate, magnesium myristate, Polypore® L 200 (Chemdal Corporation), silicone resin microbeads (Tospearl® from Toshiba, for example), spherical organopolysiloxane elastomer powders having the INCI name: Dimethicone/vinyl dimethicone crosspolymer (Dowsil Trefil E-506 S Silicone Powder®, Dowsil 9506 Powder® from Dow Corning Chemical), polyurethane powders, in particular powders of crosslinked polyurethane comprising a copolymer, said copolymer comprising trimethylol hexyllactone, for instance the hexamethylene diisocyanate/trimethylol hexyllactone polymer sold under the name Plastic Powder D-400® or Plastic Powder D-800® by Toshiki, carnauba microwaxes, such as the product sold under the name MicroCare 350® by Micro Powders, microwaxes of synthetic wax, such as the product sold under the name MicroEase 114S® by Micro Powders, microwaxes constituted of a mixture of carnauba wax and of polyethylene wax, such as those sold under the names MicroCare 300® and 310® by Micro Powders, microwaxes constituted of a mixture of carnauba wax and of synthetic wax, such as the product sold under the name MicroCare 325® by Micro Powders, polyethylene microwaxes, such as those sold under the names Micropoly 200®, 220®, 220L® and 250S® by Micro Powders; fibres of synthetic or natural and mineral or organic origin. They may be short or long, individual or organized, for example braided, and hollow or solid. They may have any shape and may in particular have a circular or polygonal (square, hexagonal or octagonal) cross section depending on the specific application envisaged. In particular, their ends are blunted and/or polished to prevent injury. The fibres have a length ranging from 1 µm to 10 mm, preferably from 0.1 mm to 5 mm and better still from 0.3 mm to 3 mm. Their cross section may be included in a circle with a diameter ranging from 2 nm to 500 µm, preferably ranging from 100 nm to 100 µm and better still from 1 µm to 50 µm; and mixtures thereof.

Particulate colorant

The particulate colorant(s) according to the invention is (are) preferably chosen from pigments, nacres and reflective particles, and mixtures thereof.

A composition according to the invention may comprise a content of particulate colorant(s) preferably ranging from 5% to 90% by weight and preferentially ranging from 10% to 70% by weight relative to the total weight of the composition.

The pulverulent phase of the composition according to the invention may comprise a content of particulate colorant(s) preferably ranging from 5% to 100% by weight and preferentially ranging from 10% to 75% by weight relative to the total weight of the pulverulent phase.

Pigments

The term “pigments” should be understood as meaning white or coloured, mineral or organic particles of any shape, which are insoluble in the physiological medium.

The pigments may be white or coloured, and mineral and/or organic.

Among the mineral pigments that may be mentioned are titanium dioxide, zirconium oxide or cerium oxide, and also zinc oxide, iron oxide (black, yellow or red) or chromium oxide, manganese violet, ultramarine blue, pink or violet, chromium hydrate and ferric blue, bismuth oxychloride and metal powders, for instance aluminium powder or copper powder.

According to a particular form of the invention, the mineral pigment comprises at least one lipophilic or hydrophobic coating.

According to a particular embodiment of the invention, the pigments may be coated according to the invention with at least one compound chosen from metal soaps; N-acylamino acids or salts thereof; lecithin and derivatives thereof; isopropyl triisostearyl titanate; isostearyl sebacate; natural plant or animal waxes; synthetic polar waxes; fatty esters; phospholipids; silicone surfactants such as organopolysiloxanes, alkylalkoxysilanes such as triethoxycaprylylsilane; fluorinated surfactants such as perfluoroalkyl phosphates, perfluoropolyethers, polytetrafluoropolyethylenes (PTFE), perfluoroalkanes, perfluoroalkyl silazanes, poly(hexafluoropropylene oxide)s, polyorganosiloxanes comprising perfluoroalkyl perfluoropolyether groups; fluorosilicone surfactants such as perfluoroalkyl dimethicones, perfluoroalkyl silanes and perfluoroalkyl trialkoxysilanes; and mixtures thereof.

According to a particular embodiment, the pigments may be coated according to the invention with an N-acylamino acid or a salt thereof, which may comprise an acyl group containing from 8 to 22 carbon atoms, for instance a 2-ethylhexanoyl, caproyl, lauroyl, myristoyl, palmitoyl, stearoyl or cocoyl group.

The amino acid may be, for example, lysine, glutamic acid or alanine. The salts of these compounds may be the aluminium, magnesium, calcium, zirconium, zinc, sodium or potassium salts. Thus, according to a particularly preferred embodiment, the pigments may be coated with an N-acylamino acid derivative which may notably be a glutamic acid derivative and/or a salt thereof, and more particularly a stearoyl glutamate, for instance aluminium stearoyl glutamate. As examples of pigments treated with aluminium stearoyl glutamate, mention may be made of titanium dioxide pigments and black, red and yellow iron oxide pigments sold under the trade name NAI® by Miyoshi Kasei.

According to a particular embodiment, the pigments can be coated according to the invention with isopropyl titanium triisostearate. Mention may be made, as examples of pigments treated with isopropyl titanium triisostearate (ITT), of those sold under the trade names BWBO-I2® (Iron Oxide CI77499 and Isopropyl Titanium Triisostearate), BWYO-I2® (Iron Oxide CI77492 and Isopropyl Titanium Triisostearate) and BWRO-I2® (Iron Oxide CI77491 and Isopropyl Titanium Triisostearate) by Kobo.

The organic pigments may be chosen from the materials below, and mixtures thereof:

- cochineal carmine,

- organic pigments of azo dyes, anthraquinone dyes, indigoid dyes, xanthene dyes, pyrene dyes, quinoline dyes, triphenylmethane dyes and fluoran dyes.

Among the organic pigments, mention may notably be made of the D&C certified pigments known under the following names: D&C Blue No. 4, D&C Brown No. 1, D&C Green No. 5, D&C Green No. 6, D&C Orange No. 4, D&C Orange No. 5, D&C Orange No. 10, D&C Orange No. 11, D&C Red No. 6, D&C Red No. 7, D&C Red No. 17, D&C Red No. 21, D&C Red No. 22, D&C Red No. 27, D&C Red No. 28, D&C Red No. 30, D&C Red No. 31, D&C Red No. 33, D&C Red No. 34, D&C Red No. 36, D&C Violet No. 2, D&C Yellow No. 7, D&C Yellow No. 8, D&C Yellow No. 10, D&C Yellow No. 11, FD&C Blue No. 1, FD&C Green No. 3, FD&C Red No. 40, FD&C Yellow No. 5, FD&C Yellow No. 6.

The chemical materials corresponding to each of the abovementioned organic colorants are mentioned in the publication “International Cosmetic Ingredient Dictionary and Handbook”, 1997 edition, pages 371 to 386 and 524 to 528, published by “The Cosmetic, Toiletries and Fragrance Association”.

More particularly, the pigments will be chosen from titanium dioxides, iron oxides (black, yellow or red), and mixtures thereof; said pigments optionally comprising at least one lipophilic or hydrophobic coating.

Nacres

The term “nacres” should be understood as meaning coloured particles of any form, which may or may not be iridescent, notably produced by certain molluscs in their shell, or else synthesized, and which have a colour effect via optical interference.

Examples of nacres that may be mentioned include nacreous pigments such as titanium mica coated with an iron oxide, mica coated with bismuth oxychloride, titanium mica coated with chromium oxide, and nacreous pigments based on bismuth oxychloride. They may also be mica particles, at the surface of which are superposed at least two successive layers of metal oxides and/or of organic colorants.

The nacres can more particularly have a yellow, pink, red, bronze, orangey, brown, green, blue, violet and/or coppery colour or tint.

As illustrations of the nacres that can be introduced into the composition, mention may also be made of the gold-coloured nacres sold notably by Engelhard under the name Brilliant Gold 212G® (Timica), Gold 222C® (Cloisonne), Sparkle Gold® (Timica), Gold 4504® (Chromalite) and Monarch Gold 233X® (Cloisonne); the bronze nacres sold notably by Merck under the name Bronze Fine® (17384) (Colorona) and Bronze® (17353) (Colorona) and by Engelhard under the name Super Bronze® (Cloisonne); the orange nacres sold notably by Engelhard under the name Orange 363C® (Cloisonne) and Orange MCR 101® (Cosmica) and by Merck under the name Passion Orange® (Colorona) and Matte Orange® (17449) (Microna); the brown nacres sold notably by Engelhard under the name Nu-Antique Copper 340XB® (Cloisonne) and Brown CL4509® (Chromalite); the nacres with a copper tint sold notably by Engelhard under the name Copper 340A® (Timica); the nacres with a red tint sold notably by Merck under the name Sienna Fine® (17386) (Colorona); the nacres with a yellow tint sold notably by Engelhard under the name Yellow® (4502) (Chromalite); the red nacres with a gold tint sold notably by Engelhard under the name Sunstone G012® (Gemtone); the pink nacres sold notably by Engelhard under the name Tan Opal G005® (Gemtone); the black nacres with a gold tint sold notably by Engelhard under the name Nu-Antique Bronze 240 AB® (Timica), the blue nacres sold notably by Merck under the name Matte Blue® (17433) (Microna), the white nacres with a silvery tint sold notably by Merck under the name Xirona Silver®, and the golden-green pink-orange nacres sold notably by Merck under the name Indian Summer® (Xirona), and mixtures thereof.

Still as examples of nacres, mention may also be made of particles including a borosilicate substrate coated with titanium oxide.

Particles comprising a glass substrate coated with titanium oxide are notably sold under the name Metashine MC1080RY by Toyal.

Finally, examples of nacres that may also be mentioned include polyethylene terephthalate glitter flakes, notably those sold by Meadowbrook Inventions under the name Silver 1P 0.004X0.004® (silver glitter flakes).

A composition according to the invention may comprise a nacre content preferably ranging from 1% to 50% by weight, more preferentially ranging from 1% to 30% by weight relative to the total weight of the composition.

Reflective particles

The term “reflective particles” denotes particles of which the size, structure, especially the thickness of the layer(s) of which they are made and their physical and chemical nature, and surface state, allow them to reflect incident light. This reflection may, where appropriate, have an intensity sufficient to create at the surface of the composition or of the mixture, when it is applied to the support to be made up, highlight points that are visible to the naked eye, i.e. more luminous points that contrast with their environment making them appear to sparkle.

The reflective particles may be selected so as not to significantly alter the coloration effect generated by the colouring agents with which they are combined, and more particularly so as to optimize this effect in terms of colour rendition. They may more particularly have a yellow, pink, red, bronze, orange, brown, gold and/or coppery colour or tint.

These particles may have varied forms and may notably be in platelet or globular form, in particular in spherical form.

The reflective particles, whatever their form, may or may not have a multilayer structure and, in the case of a multilayer structure, may have, for example, at least one layer of uniform thickness, notably of a reflective material.

When the reflective particles do not have a multilayer structure, they may be composed, for example, of metal oxides, notably titanium or iron oxides obtained synthetically.

When the reflective particles have a multilayer structure, they may include, for example, a natural or synthetic substrate, notably a synthetic substrate at least partially coated with at least one layer of a reflective material, notably of at least one metal or metallic material. The substrate may be made of one or more organic and/or mineral materials.

More particularly, it may be chosen from glasses, ceramics, graphite, metal oxides, aluminas, silicas, silicates, notably aluminosilicates and borosilicates, and synthetic mica, and mixtures thereof, this list not being limiting.

The reflective material may include a layer of metal or of a metallic material.

Reflective particles are notably described in JP-A-09188830, JP-A-10158450, JP-A-10158541, JP-A-07258460 and JP-A-05017710.

Again as an example of reflective particles including a mineral substrate coated with a layer of metal, mention may also be made of particles including a silver-coated borosilicate substrate.

Particles with a silver-coated glass substrate, in the form of platelets, are sold under the name Microglass Metashine REFSX 2025 PS® by Toyal. Particles with a glass substrate coated with a nickel/chromium/molybdenum alloy are sold under the names Crystal Star GF 550® and GF 2525® by this same company.

Use may also be made of particles comprising a metal substrate, such as silver, aluminium, iron, chromium, nickel, molybdenum, gold, copper, zinc, tin, magnesium, steel, bronze or titanium, said substrate being coated with at least one layer of at least one metal oxide, such as titanium oxide, aluminium oxide, iron oxide, cerium oxide, chromium oxide, silicon oxides and mixtures thereof.

Examples that may be mentioned include aluminium powder, bronze powder or copper powder coated with SiO₂, sold under the name Visionaire® by Eckart.

According to a particular form of the invention, the particulate colorant(s) is (are) chosen from:

- titanium dioxide (CI: 77891) such as the commercial product Hombitan FF Pharma® sold by Venator;

- yellow iron oxide (CI: 77492), red iron oxide (CI: 77491), black iron oxide (CI: 77499), and mixtures thereof, such as the products sold under the trade name Sunpuro® by Sun;

- nacres, for instance those based on mica covered with titanium dioxide and/or iron oxide, such as the product sold under the trade name Timiron Pearl Sheen MP 30® by Merck; those based on mica, barium sulfate and titanium dioxide, such as the product sold under the trade name Ronaflair Low Luster Pigment® by Merck;

- bismuth oxychloride, such as the product sold under the trade name Ronaflair LF 2000® by Merck;

- mixtures thereof.

More particularly, the particulate colorant(s) will be chosen from pigments and more particularly from titanium dioxides, iron oxides (black, yellow or red), and mixtures thereof; said pigments optionally comprising at least one lipophilic or hydrophobic coating agent.

Film-forming polymer

The composition of the invention comprises at least one film-forming polymer solubilized in at least one volatile solvent; said composition being obtained by a preparation process comprising at least one step of grinding said film-forming polymer in solid form with at least one portion of the pulverulent phase, notably the particulate colorants present in the composition.

For the purposes of the invention, the term “polymer” is understood to mean a compound corresponding to the repetition of one or more units (these units resulting from compounds known as monomers). This or these unit(s) is (are) repeated at least twice and preferably at least three times.

The term “film-forming polymer” is understood to mean a polymer capable of forming, by itself alone or in the presence of an auxiliary film-forming agent, a macroscopically continuous film on a support, in particular on keratin materials, preferably a cohesive film, and better still a film, the cohesion and the mechanical properties of which are such that said film can be isolable and manipulable in isolation, for example when said film is prepared by pouring onto a non-stick surface, such as a Teflon-coated or silicone-coated surface.

The term “polymer solubilized in at least one volatile solvent” means the state of the polymer at ambient temperature (25°C) and atmospheric pressure (760 mmHg or 10⁵ Pa); said polymer being present in the composition of the invention in a fluid form in the solubilized state in at least one volatile solvent, in particular in at least one volatile organic solvent, and more particularly in at least one volatile oil.

The term “polymer in the solid state” means the state of the polymer at ambient temperature (25°C) and atmospheric pressure (760 mmHg or 10⁵ Pa); said polymer is not present in the composition of the invention in a fluid form in the solubilized state in an organic solvent, in particular a volatile organic solvent.

Preferentially, a composition according to the invention comprises from 5% to 60% by weight, more preferentially from 10% to 50% by weight, more particularly from 20% to 40% by weight, as active material of film-forming polymer(s) in solubilized form, relative to the total weight of the composition.

The film-forming polymers in accordance with the invention are preferably chosen from hydrophobic film-forming polymers.

For the purposes of the present invention, the term “hydrophobic film-forming polymer” is understood to denote a film-forming polymer which is devoid of affinity for water and, as such, which does not lend itself to a formulation in the form of a solute in an aqueous medium. In particular, the term “hydrophobic polymer” is understood to mean a polymer having a solubility in water at 25°C of less than 1% by weight.

In particular, the hydrophobic film-forming polymer is a polymer chosen from the group comprising film-forming polymers which are soluble in an organic solvent medium, in particular fat-soluble polymers; this means that the polymer is soluble or miscible in the organic medium and will form a single homogeneous phase when it is incorporated in the medium.

According to a particular form of the invention, the hydrophobic film-forming polymer(s) is (are) chosen from

- a silicone resin;

- a copolymer comprising carboxylate groups and polydimethylsiloxane groups;

- a vinyl polymer comprising at least one carbosiloxane dendrimer-based unit;

- an ethylene block copolymer;

- a polysaccharide grafted with organosiloxane groups;

- a polysaccharide ether;

- a norbornene polymer grafted with organosiloxane groups;

- mixtures thereof.

Silicone resins

More generally, the term “resin” means a compound of which the structure is three-dimensional. “Silicone resins” are also referred to as “siloxane resins”.

The nomenclature of silicone resins (also known as siloxane resins) is known under the name “MDTQ”, the resin being described as a function of the various siloxane monomer units it comprises, each of the letters MDTQ characterizing a type of unit.

The letter M represents the monofunctional unit of formula R₁R₂R₃SiO_1/2, the silicon atom being connected to only one oxygen atom in the polymer comprising this unit.

The letter D means a difunctional unit R₁R₂1SiO_2/2 in which the silicon atom is connected to two oxygen atoms.

The letter T represents a trifunctional unit R₁SiO_3/2.

Such resins are described, for example, in the Encyclopedia of Polymer Science and Engineering, vol. 15, John Wiley & Sons, New York, (1989), pp. 265-270, and US 2 676 182, US 3 627 851, US 3 772 247, US 5 248 739 or US 5 082 706, US 5 319 040, US 5 302 685 and US 4 935 484.

In the M, D and T units defined previously, R, namely R₁, R₂ and R₃, represents a hydrocarbon (notably alkyl) radical containing from 1 to 10 carbon atoms, a phenyl group, a phenylalkyl group or a hydroxyl group.

Finally, the letter Q means a tetrafunctional unit SiO_4/2 in which the silicon atom is bonded to four oxygen atoms, which are themselves bonded to the rest of the polymer.

Various silicone resins with different properties can be obtained from these different units, the properties of these polymers varying as a function of the type of monomer (or units), of the nature and number of the R radical, of the length of the polymer chain, of the degree of branching and of the size of the pendent chains.

Use may be made, as silicone resins which can be used in the compositions according to the invention, for example, of silicone resins of MQ type, of T type or of MQT type.

MQ resins:

As examples of silicone resins of MQ type, mention may be made of the alkylsiloxysilicates of formula [(R₁)₃SiO_1/2]_x(SiO_4/2)_y (MQ units) in which x and y are integers ranging from 50 to 80, and such that the group R₁ represents a radical as defined previously, and is preferably an alkyl group containing from 1 to 8 carbon atoms or a hydroxyl group, preferably a methyl group.

As an example of MQ silicone resins, mention will be made of those with the INCI name trimethylsiloxysilicate such as those sold under the reference SR1000® by General Electric and under the reference Belsil TMS 803® by Wacker.

T resins:

Examples of silicone resins of type T that may be mentioned include the polysilsesquioxanes of formula (RSiO_3/2)_x (T units) wherein x is greater than 100 and such that the group R is an alkyl group containing from 1 to 10 carbon atoms, said polysilsesquioxanes also possibly comprising Si-OH end groups.

Preferably, use may be made of the polymethylsilsesquioxane resins wherein R represents a methyl group, for instance those sold by Wacker under the reference Resin MK®, such as Belsil PMS MK®: a polymer comprising CH₃SiO_3/2 repeat units (T units), also possibly comprising up to 1% by weight of (CH₃)₂SiO_2/2 units (D units) and having an average molecular weight of around 10 000 g/mol.

MQT resins:

Resins comprising MQT units that are notably known are those mentioned in US 5 110 890.

A preferred form of resins of MQT type are MQT-propyl (also known as MQTPr) resins. Such resins that may be used in the compositions according to the invention are especially the resins described and prepared in patent application WO 2005/075 542.

The MQ-T-propyl resin preferably comprises the units:

(i) (R1₃SiO_1/2)_a

(ii) (R2₂SiO_2/2)_b

(iii) (R3SiO_3/2)_c and

(iv) (SiO_4/2)_d

With R1, R2 and R3 independently representing a hydrocarbon (notably alkyl) radical containing from 1 to 10 carbon atoms, a phenyl group, a phenylalkyl group or a hydroxyl group and preferably an alkyl radical containing from 1 to 8 carbon atoms or a phenyl group,

a, b, c and d being mole fractions,

a being between 0.05 and 0.5,

b being between 0 and 0.3,

c being greater than zero,

d being between 0.05 and 0.6,

a + b + c + d = 1,

on condition that more than 40 mol% of the R3 groups of the siloxane resin are propyl groups.

Preferably, the siloxane resin comprises the units:

(i) (R1₃SiO_1/2)_a

(ii) (R3SiO_3/2)_c and

(iv) (SiO_4/2)_d

with R1 and R3 independently representing an alkyl group containing from 1 to 8 carbon atoms, R1 preferably being a methyl group and R3 preferably being a propyl group,

a being between 0.05 and 0.5 and preferably between 0.15 and 0.4,

c being greater than zero, preferably between 0.15 and 0.4,

d being between 0.05 and 0.6, preferably between 0.2 and 0.6 or alternatively between 0.2 and 0.55,

a + b + c + d = 1, and a, b, c and d being mole fractions,

provided that more than 40 mol% of the R3 groups of the siloxane resin are propyl groups.

The siloxane resins which can be used according to the invention can be obtained by a process comprising the reaction of:

A) an MQ resin comprising at least 80 mol% of units (R1₃SiO_1/2)_a and (SiO_4/2)_d,

R1 representing an alkyl group containing from 1 to 8 carbon atoms, an aryl group, a carbinol group or an amino group,

a and d being greater than zero,

the ratio a/d being between 0.5 and 1.5; and

B) a propyl T resin comprising at least 80 mol% of (R₃SiO_3/2)_c units,

R3 representing an alkyl group containing from 1 to 8 carbon atoms, an aryl group, a carbinol group or an amino group,

c being greater than zero,

on condition that at least 40 mol% of the groups R3 are propyl groups,

where the weight ratio A/B is between 95:5 and 15:85 and preferably the weight ratio A/B is 30:70.

Advantageously, the weight ratio A/B is between 95:5 and 15:85. Preferably, the ratio A/B is less than or equal to 70:30. These preferred ratios have proven to afford comfortable deposits.

Preferably, the composition according to the invention comprises, as silicone resin, at least one resin of MQ type, more particularly of trimethylsiloxysilicate type, such as those sold under the reference SR1000® by Momentive Performance Materials and under the reference TMS 803® by Wacker.

Copolymers comprising carboxylate groups and polydimethylsiloxane groups

The expression “copolymer comprising carboxylate groups and polydimethylsiloxane groups” is understood to mean, in the present patent application, a copolymer obtained from (a) one or more carboxylic (acid or ester) monomers and (b) one or more polydimethylsiloxane (PDMS) chains.

In the present patent application, the term “carboxylic monomer” means both carboxylic acid monomers and carboxylic acid ester monomers.

Thus, the monomer (a) may be chosen, for example, from acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, esters thereof and mixtures of these monomers.

Esters that may be mentioned include the following monomers: acrylate, methacrylate, maleate, fumarate, itaconate and/or crotonate.

According to a preferred embodiment of the invention, the monomers in ester form are more particularly chosen from linear or branched, preferably C₁-C₂₄ and better still C₁-C₂₂ alkyl acrylates and methacrylates, the alkyl radical preferentially being chosen from methyl, ethyl, stearyl, butyl and 2-ethylhexyl radicals, and mixtures thereof.

Thus, according to a particular embodiment of the invention, the copolymer comprises as carboxylate groups at least one group chosen from acrylic acid and methacrylic acid, and methyl, ethyl, stearyl, butyl or 2-ethylhexyl acrylates or methacrylates, and mixtures thereof.

In the present patent application, the term “polydimethylsiloxanes” (also called organopolysiloxanes or abbreviated as PDMSs) denotes, in accordance with what is generally accepted, any organosilicon polymer or oligomer of linear structure, of variable molecular weight, obtained by polymerization and/or polycondensation of suitably functionalized silanes, and constituted essentially of a repetition of main units wherein the silicon atoms are linked together via oxygen atoms (siloxane bond ºSi-O-Siº), including trimethyl radicals directly linked via a carbon atom to said silicon atoms. The PDMS chains that may be used to obtain the copolymer used according to the invention include at least one polymerizable radical group, preferably located on at least one of the ends of the chain, i.e. the PDMS may contain, for example, a polymerizable radical group on the two ends of the chain or one polymerizable radical group on one end of the chain and one trimethylsilyl end group on the other end of the chain. The polymerizable radical group may especially be an acrylic or methacrylic group, in particular a CH₂=CR1-COO-R2 group

wherein R1 represents hydrogen or a methyl group and R2 represents

-CH₂-, -(CH₂)_n- with n = 3, 5, 8 or 10, -CH₂–CH(CH₃)–CH₂-, -CH₂-CH₂-CH₂-,

-CH₂-CH₂-O-CH₂-CH₂-CH(CH₃)-CH₂-, -CH₂-CH₂-O-CH₂-CH₂-O-CH₂-CH₂-CH₂–.

The copolymers used in the composition of the invention are generally obtained according to the usual methods of polymerization and grafting, for example by free-radical polymerization (A) of a PDMS comprising at least one polymerizable radical group (for example on one of the ends of the chain or on both ends) and (B) of at least one carboxylic monomer, as described, for example, in documents US-A-5 061 481 and US-A-5 219 560.

The copolymers obtained generally have a molecular weight ranging from 3000 to 200 000 and preferably from 5000 to 100 000.

As copolymers that may be used in the composition of the invention, mention may be made, for example, of copolymers of acrylic acid and of stearyl acrylate bearing polydimethylsiloxane grafts, copolymers of stearyl methacrylate bearing polydimethylsiloxane grafts, copolymers of acrylic acid and of stearyl methacrylate bearing polydimethylsiloxane grafts, copolymers of methyl methacrylate, butyl methacrylate, 2-ethylhexyl acrylate and stearyl methacrylate bearing polydimethylsiloxane grafts.

Mention may be made, in particular, as copolymer which can be used in the composition of the invention, of the copolymer having the INCI name Acrylates/Ethylhexyl Acrylate/Dimethicone Methacrylate, such as the commercial product

KP-561® sold by Shin Etsu.

Vinyl polymers grafted with a carbosiloxane dendrimer

The vinyl polymer has a backbone and at least one side chain, which side chain comprises a carbosiloxane dendrimer-based unit having a carbosiloxane dendrimer structure.

In the context of the present invention, the term “carbosiloxane dendrimer structure” represents a molecular structure possessing branched groups having high molecular weights, said structure having high regularity in the radial direction starting from the bond to the backbone. Such carbosiloxane dendrimer structures are described in the form of a highly branched siloxane-silylalkylene copolymer in the laid-open Japanese patent application Kokai 9-171154.

A vinyl polymer according to the invention may contain carbosiloxane dendrimer-based units that may be represented by the following general formula (I):

(I)

in which:

- R¹ represents an aryl group having from 5 to 10 carbon atoms or an alkyl group having from 1 to 10 carbon atoms;

- Xⁱ represents a silylalkyl group which, when i = 1, is represented by formula (II):

(II)

in which:

R¹ is as defined above in the formula (I),

R² represents an alkylene radical having from 2 to 10 carbon atoms,

R³ represents an alkyl group having from 1 to 10 carbon atoms,

Xⁱ⁺¹ is chosen from: a hydrogen atom, an alkyl group having from 1 to 10 carbon atoms, an aryl group having from 5 to 10 carbon atoms and a silylalkyl group defined above of formula (II),

i is an integer from 1 to 10 which represents the generation of said silylalkyl group, and

aⁱ is an integer from 0 to 3;

Y represents a radical-polymerizable organic group chosen from:

organic groups comprising a methacrylic group or an acrylic group, said organic groups being represented by the formulae:

or

in which:

R⁴ represents a hydrogen atom or an alkyl group containing from 1 to 10 carbon atoms; and

R⁵ represents an alkylene group having from 1 to 10 carbon atoms, such as a methylene group, an ethylene group, a propylene group or a butylene group, methylene and propylene groups being preferred; and

organic groups containing a styryl group of formula:

in which:

R⁶ represents a hydrogen atom or an alkyl group having from 1 to 10 carbon atoms, such as a methyl group, an ethyl group, a propyl group or a butyl group, the methyl group being preferred;

R⁷ represents an alkyl group having from 1 to 10 carbon atoms;

R⁸ represents an alkylene group having from 1 to 10 carbon atoms, such as a methylene group, an ethylene group, a propylene group or a butylene group, the ethylene group being preferred;

b is an integer from 0 to 4; and

c has the value 0 or 1, so that, if c has the value 0, -(R⁸)_c- represents a bond.

According to one embodiment, R¹ can represent an aryl group possessing from 5 to 10 carbon atoms or an alkyl group possessing from 1 to 10 carbon atoms. The alkyl group can preferably be represented by a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, an isopropyl group, an isobutyl group, a cyclopentyl group or a cyclohexyl group. The aryl group can preferably be represented by a phenyl group and a naphthyl group. The methyl and phenyl groups are more particularly preferred, and the methyl group is most preferred.

According to one embodiment, R² represents an alkylene group containing from 2 to 10 carbon atoms, in particular a linear alkylene group, such as an ethylene, propylene, butylene or hexylene group; or a branched alkylene group, such as a methylmethylene, methylethylene, 1-methylpentylene or 1,4-dimethylbutylene group. The ethylene, methylethylene, hexylene, 1-methylpentylene and 1,4-dimethylbutylene groups are most preferred.

According to one embodiment, R³ is chosen from methyl, ethyl, propyl, butyl and isopropyl groups.

In the formula (II), i indicates the number of generations and thus corresponds to the number of repetitions of the silylalkyl group.

For example, when the number of generations is equal to one, the carbosiloxane dendrimer can be represented by the general formula below:

wherein Y, R¹, R² and R³ are as defined above, R¹² represents a hydrogen atom or is identical to R¹; a¹ is identical to aⁱ. Preferably, the total average number of OR³ groups in a molecule is within the range from 0 to 7.

When the number of generations is equal to 2, the carbosiloxane dendrimer can be represented by the general formula below:

wherein Y, R¹, R², R³ and R¹² are the same as defined above; a¹ and a² represent the aⁱ of the generation indicated. Preferably, the total average number of OR³ groups in a molecule is within the range from 0 to 25.

In the case wherein the number of generations is equal to 3, the carbosiloxane dendrimer is represented by the general formula below:

wherein Y, R¹, R², R³ and R¹² are the same as defined above; a¹, a² and a³ represent the aⁱ of the generation indicated. Preferably, the total average number of OR³ groups in a molecule is within the range from 0 to 79.

A vinyl polymer containing at least one carbosiloxane dendrimer-based unit has a molecular side chain containing a carbosiloxane dendrimer structure, and may be the product of polymerization of:

(A) from 0 to 99.9 parts by weight of a vinyl monomer; and

(B) from 100 to 0.1 parts by weight of a carbosiloxane dendrimer containing a radically polymerizable organic group, represented by general formula (I) as defined above.

The monomer of vinyl type which is the component (A) in the vinyl polymer having at least one carbosiloxane dendrimer-based unit is a monomer of vinyl type which comprises a radically polymerizable vinyl group. There is no particular limitation as regards such a monomer.

The following are examples of this monomer of vinyl type: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate or a methacrylate of a lower alkyl analogue; glycidyl methacrylate; butyl methacrylate, butyl acrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, octyl methacrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate or a higher methacrylate analogue; vinyl acetate, vinyl propionate or a vinyl ester of a lower fatty acid analogue; vinyl caproate, vinyl 2-ethylhexoate, vinyl laurate, vinyl stearate or a higher fatty acid ester analogue; styrene, vinyltoluene, benzyl methacrylate, phenoxyethyl methacrylate, vinylpyrrolidone or similar vinylaromatic monomers; methacrylamide, N-methylolmethacrylamide, N-methoxymethylmethacrylamide, isobutoxymethoxymethacrylamide, N,N-dimethylmethacrylamide or similar monomers of vinyl type containing amide groups; hydroxyethyl methacrylate, hydroxypropyl alcohol methacrylate or similar monomers of vinyl type containing hydroxyl groups; acrylic acid, methacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or similar monomers of vinyl type containing a carboxylic acid group; tetrahydrofurfuryl methacrylate, butoxyethyl methacrylate, ethoxydiethylene glycol methacrylate, polyethylene glycol methacrylate, polypropylene glycol monomethacrylate, hydroxybutyl vinyl ether, cetyl vinyl ether, 2-ethylhexyl vinyl ether or a similar monomer of vinyl type with ether bonds; methacryloxypropyltrimethoxysilane, polydimethylsiloxane containing a methacrylic group on one of its molecular ends, polydimethylsiloxane containing a styryl group on one of its molecular ends, or a similar silicone compound containing unsaturated groups; butadiene; vinyl chloride; vinylidene chloride; methacrylonitrile; dibutyl fumarate; anhydrous maleic acid; anhydrous succinic acid; methacryl glycidyl ether; an organic salt of an amine, an ammonium salt, and an alkali metal salt of methacrylic acid, of itaconic acid, of crotonic acid, of maleic acid or of fumaric acid; a radically polymerizable unsaturated monomer containing a sulfonic acid group such as a styrenesulfonic acid group; a quaternary ammonium salt derived from methacrylic acid, such as 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride; and a methacrylic acid ester of an alcohol containing a tertiary amine group, such as a methacrylic acid ester of diethylamine.

Multifunctional monomers of vinyl type may also be used.

The following represent examples of such compounds: trimethylolpropane trimethacrylate, pentaerythrityl trimethacrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropanetrioxyethyl methacrylate, tris(2-hydroxyethyl)isocyanurate dimethacrylate, tris(2-hydroxyethyl)isocyanurate trimethacrylate, polydimethylsiloxane capped with styryl groups containing divinylbenzene groups on both ends, or similar silicone compounds containing unsaturated groups.

A carbosiloxane dendrimer, which is the component (B), can be represented by the formula (I) as defined above.

The following represent the preferred examples of Y group of the formula (I): an acryloyloxymethyl group, a 3-acryloyloxypropyl group, a methacryloyloxymethyl group, a 3-methacryloyloxypropyl group, a 4-vinylphenyl group, a 3-vinylphenyl group, a 4-(2-propenyl)phenyl group, a 3-(2-propenyl)phenyl group, a 2-(4-vinylphenyl)ethyl group, a 2-(3-vinylphenyl)ethyl group, a vinyl group, an allyl group, a methallyl group and a 5-hexenyl group.

A carbosiloxane dendrimer according to the present invention may be represented by the formulae having the average structures below:

Thus, according to one embodiment, the carbosiloxane dendrimer of the composition according to the present invention is represented by the following formula:

in which:

Y, R¹, R² and R³ are as defined in the formulae (I) and (II) above;

a¹, a² and a³ correspond to the definition of aⁱ according to formula (II); and

R¹² is H, an aryl group having from 5 to 10 carbon atoms or an alkyl group having from 1 to 10 carbon atoms.

According to one embodiment, the carbosiloxane dendrimer of the composition according to the present invention is represented by one of the following formulae:

The vinyl polymer comprising the carbosiloxane dendrimer according to the invention may be manufactured according to the process for manufacturing a branched silalkylene siloxane described in Japanese patent application Hei 9-171 154.

For example, it may be produced by subjecting an organosilicon compound containing a hydrogen atom linked to a silicon atom, represented by the following general formula (IV):

(IV)

with R¹ being as defined above in the formula (I),

and an organosilicon compound containing an alkenyl group, to a hydrosilylation reaction.

In the above formula, the organosilicon compound can be represented by (3-methacryloyloxypropyl)tris(dimethylsiloxy)silane, (3-acryloyloxypropyl)tris(dimethylsiloxy)silane and (4-vinylphenyl)tris(dimethylsiloxy)silane. The organosilicon compound containing an alkenyl group may be vinyltris(trimethylsiloxy)silane, vinyltris(dimethylphenylsiloxy)silane, and 5-hexenyltris(trimethylsiloxy)silane.

The hydrosilylation reaction is performed in the presence of a chloroplatinic acid, a complex of vinylsiloxane and of platinum, or a similar transition metal catalyst.

A vinyl polymer bearing at least one carbosiloxane dendrimer-based unit may be chosen from polymers such that the carbosiloxane dendrimer-based unit is a carbosiloxane dendritic structure represented by formula (III) below:

(III)

wherein Z is a divalent organic group, “p” is 0 or 1, R¹ is as defined above in formula (IV) and Xⁱ is a silylalkyl group represented by formula (II) as defined above.

In a vinyl polymer having at least one unit derived from carbosiloxane dendrimer, the polymerization ratio of the component (A) to the component (B), in terms of the ratio by weight of (A) to (B), is within a range from 0/100 to 99.9/0.1, indeed even from 0.1/99.9 to 99.9/0.1 and preferably within a range from 1/99 to 99/1. A ratio of the component (A) to the component (B) of 0/100 means that the compound becomes a homopolymer of component (B).

A vinyl polymer having at least one carbosiloxane dendrimer-based unit can be obtained by the copolymerization of the components (A) and (B) or by the polymerization of the component (B) alone.

The polymerization can be a radical polymerization or an ionic polymerization; however, the radical polymerization is preferred.

The polymerization may be performed by bringing about a reaction between the components (A) and (B) in a solution for a period of from 3 to 20 hours in the presence of a radical initiator at a temperature of from 50°C to 150°C.

A suitable solvent for this purpose is hexane, octane, decane, cyclohexane or a similar aliphatic hydrocarbon; benzene, toluene, xylene or a similar aromatic hydrocarbon; diethyl ether, dibutyl ether, tetrahydrofuran, dioxane or ethers; acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone or similar ketones; methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate or similar esters; methanol, ethanol, isopropanol, butanol or similar alcohols; octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethyldisiloxane, octamethyltrisiloxane or a similar organosiloxane oligomer.

A radical initiator may be any compound known in the art for standard free-radical polymerization reactions. The specific examples of such radical initiators are 2,2’-azobis(isobutyronitrile), 2,2’-azobis(2-methylbutyronitrile), 2,2’-azobis(2,4-dimethylvaleronitrile) or similar compounds of azobis type; benzoyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate or a similar organic peroxide. These radical initiators can be used alone or in a combination of two or more. The radical initiators can be used in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the components (A) and (B). A chain-transfer agent can be added. The chain-transfer agent can be 2-mercaptoethanol, butyl mercaptan, n-dodecyl mercaptan, (3-mercaptopropyl)trimethoxysilane, a polydimethylsiloxane possessing a mercaptopropyl group or a similar compound of mercapto type; methylene chloride, chloroform, carbon tetrachloride, butyl bromide, (3-chloropropyl)trimethoxysilane or a similar halogenated compound.

In the manufacture of the polymer of vinyl type, after the polymerization, the unreacted residual vinyl monomer may be removed under conditions of heating under vacuum.

To facilitate the preparation of starting material for cosmetic products, the number-average molecular weight of the vinyl polymer which comprises a carbosiloxane dendrimer can be chosen within the range between 3000 and 2 000 000 and preferably between 5000 and 800 000. It may be a liquid, gum, paste, solid, powder, or any other form. The preferred forms are solutions consisting of the dilution of a dispersion or of a powder in solvents.

A vinyl polymer that is suitable for use in the invention may also be one of the polymers described in the examples of patent application EP 0 963 751.

According to a preferred embodiment, a vinyl polymer grafted with a carbosiloxane dendrimer may be the product of polymerization of:

- of 0 to 99.9 parts by weight of one or more acrylate or methacrylate monomer(s); and

- of 100 to 0.1 parts by weight of an acrylate or methacrylate monomer of a tris[tri(trimethylsiloxy)silylethyldimethylsiloxy]silylpropyl carbosiloxane dendrimer.

The monomers (A1) and (B1) correspond respectively to specific monomers (A) and (B).

According to one embodiment, a vinyl polymer bearing at least one carbosiloxane dendrimer-based unit may comprise a tris[tri(trimethylsiloxy)silylethyldimethylsiloxy]silylpropyl carbosiloxane dendrimer-based unit corresponding to one of the formulae:

According to one preferred mode, a vinyl polymer bearing at least one carbosiloxane dendrimer-based unit used in the invention comprises at least one butyl acrylate monomer.

According to one embodiment, a vinyl polymer may also comprise at least one fluorinated organic group. A fluorinated vinyl polymer may be one of the polymers described in the examples of patent application WO 03/045 337.

The vinyl polymers grafted with at least one carbosiloxane dendrimer-based unit which may be particularly suitable for the present invention are those having the INCI name: Acrylates/Polytrimethylsiloxymethacrylate and corresponding to the solid state polymer of the commercial products Dowsil FA 4002 ID Silicone Acrylate® and Dowsil FA 4004 ID Silicone Acrylate® sold by Dow Corning.

Block ethylenic copolymers

According to a preferential form, the block ethylenic copolymer (also referred to as block ethylene polymer) in accordance with the invention contains at least one first block with a glass transition temperature (Tg) above or equal to 40°C and being totally or partly derived from one or more first monomers, which are such that the homopolymer prepared from these monomers has a glass transition temperature above or equal to 40°C, and at least one second block with a glass transition temperature below or equal to 20°C and being totally or partly derived from one or more second monomers, which are such that the homopolymer prepared from these monomers has a glass transition temperature below or equal to 20°C, said first block and said second block being connected together via a statistical intermediate segment comprising at least one of said first constituent monomers of the first block and at least one of said second constituent monomers of the second block, and said block copolymer having a polydispersity index I of greater than 2.

The block polymer used according to the invention thus comprises at least one first block and at least one second block.

The term “at least one block” means one or more blocks.

The term “block” polymer means a polymer comprising at least two different blocks and preferably at least three different blocks.

The term “ethylenic polymer” means a polymer obtained by polymerization of ethylenically unsaturated monomers.

The block ethylenic polymer used according to the invention is prepared exclusively from monofunctional monomers.

This means that the block ethylenic polymer used according to the present invention does not contain any multifunctional monomers, which make it possible to break the linearity of a polymer so as to obtain a branched or even crosslinked polymer, as a function of the content of multifunctional monomer. The polymer used according to the invention does not, either, contain any macromonomers (the term “macromonomer” means a monofunctional monomer containing a pendent group of polymeric nature, and preferably having a molecular mass of greater than 500 g/mol, or alternatively a polymer including on only one of its ends a polymerizable (or ethylenically unsaturated) end group), which are used in the preparation of a grafted polymer.

It is pointed out that, in the text hereinabove and hereinbelow, the terms “first” and “second” blocks do not in any way condition the order of said blocks in the structure of the polymer.

The first block and the second block of the polymer used in the invention may be advantageously mutually incompatible.

The term “mutually incompatible blocks” means that the mixture formed from a polymer corresponding to the first block and from a polymer corresponding to the second block is not miscible in the polymerization solvent that is in major amount by weight for the block polymer, at room temperature (25°C) and atmospheric pressure (10⁵ Pa), for a content of the mixture of said polymers of greater than or equal to 5% by weight, relative to the total weight of the mixture of said polymers and of said polymerization solvent, it being understood that:

i) said polymers are present in the mixture in a content such that the respective weight ratio ranges from 10/90 to 90/10, and that

ii) each of the polymers corresponding to the first and second blocks has an average (weight-average or number-average) molecular mass equal to that of the block polymer ± 15%.

In the case of a mixture of polymerization solvents, and in the event that two or more solvents are present in identical mass proportions, said polymer mixture is immiscible in at least one of them.

Needless to say, in the case of a polymerization performed in a single solvent, this solvent is the solvent that is in major amount.

The block polymer according to the invention comprises at least a first block and at least a second block that are connected together via an intermediate segment comprising at least one constituent monomer of the first block and at least one constituent monomer of the second block. The intermediate segment (also known as the intermediate block) has a glass transition temperature Tg that is between the glass transition temperatures of the first and second blocks.

The intermediate segment is a block comprising at least one constituent monomer of the first block and at least one constituent monomer of the second block of the polymer allowing these blocks to be “compatibilized”.

Advantageously, the intermediate segment comprising at least one constituent monomer of the first block and at least one constituent monomer of the second block of the polymer is a statistical polymer.

Preferably, the intermediate block is derived essentially from constituent monomers of the first block and of the second block.

The term “essentially” means at least 85%, preferably at least 90%, better still 95% and even better still 100%.

Preferentially, the polymer according to the invention does not comprise any silicon atoms in its backbone.

The term “backbone” means the main chain of the polymer, as opposed to the pendent side chains.

Preferably, the polymer according to the invention is not water-soluble, i.e. the polymer is not soluble in water or in a mixture of water and linear or branched lower monoalcohols containing from 2 to 5 carbon atoms, for instance ethanol, isopropanol or n-propanol, without modifying the pH, at an active material content of at least 1% by weight, at room temperature (25°C).

Preferably, the polymer according to the invention is not an elastomer.

The term “non-elastomeric polymer” means a polymer which, when it is subjected to a stress intended to stretch it (for example by 30% relative to its initial length), does not return to a length substantially identical to its initial length when the stress ceases.

The polydispersity index of the polymer of the invention is greater than 2.

Advantageously, the block polymer used in the compositions according to the invention has a polydispersity index I of greater than 2, for example ranging from 2 to 9, preferably greater than or equal to 2.5, for example ranging from 2.5 to 8 and better still greater than or equal to 2.8, and in particular ranging from 2.8 to 6.

The polydispersity index I of the polymer is equal to the ratio of the weight-average mass Mw to the number-average mass Mn.

The weight-average molar mass (Mw) and number-average molar mass (Mn) are determined by gel permeation liquid chromatography (THF solvent, calibration curve established with linear polystyrene standards, refractometer detector).

The weight-average mass (Mw) of the polymer according to the invention is preferably less than or equal to 300 000 g/mol; it ranges, for example, from 35 000 to 200 000 g/mol and better still from 45 000 to 150 000 g/mol.

The number-average mass (Mn) of the polymer according to the invention is preferably less than or equal to 70 000 g/mol; it ranges, for example, from 10 000 to 60 000 g/mol and better still from 12 000 to 50 000 g/mol.

Preferably, the polydispersity index of the polymer according to the invention is greater than 2, for example ranging from 2 to 9, preferably greater than or equal to 2.5, for example ranging from 2.5 to 8, and better still greater than or equal to 2.8, and notably ranging from 2.8 to 6.

First block with a Tg above or equal to 40°C

The block with a Tg above or equal to 40°C has, for example, a Tg ranging from 40°C to 150°C, preferably above or equal to 50°C, for example ranging from 50°C to 120°C and better still above or equal to 60°C, for example ranging from 60°C to 120°C.

The glass transition temperatures indicated for the first and second blocks may be theoretical Tg values determined from the theoretical Tg values of the constituent monomers of each of the blocks, which may be found in a reference manual such as the Polymer Handbook, 3rd Edition, 1989, John Wiley, according to the following relationship, known as the Fox equation:

[Math 2]

1/Tg= Σ (ωi / Tgi),

ωi being the weight fraction of the monomer i in the block under consideration and Tgi being the glass transition temperature of the homopolymer of the monomer i.

Unless otherwise indicated, the Tg values indicated for the first and second blocks in the present patent application are theoretical Tg values.

The difference between the glass transition temperatures of the first and second blocks is generally greater than 10°C, preferably greater than 20°C and better still greater than 30°C.

The block with a Tg above or equal to 40°C may be a homopolymer or a copolymer.

The block with a Tg above or equal to 40°C may be derived totally or partially from one or more monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature above or equal to 40°C. This block may also be referred to as a “rigid block”.

In the case where this block is a homopolymer, it is derived from monomers which are such that the homopolymers prepared from these monomers have glass transition temperatures above or equal to 40°C. This first block may be a homopolymer constituted of only one type of monomer (for which the Tg of the corresponding homopolymer is above or equal to 40°C).

In the case where the first block is a copolymer, it may be totally or partially derived from one or more monomers, the nature and concentration of which are chosen such that the Tg of the resulting copolymer is above or equal to 40°C. The copolymer may comprise, for example:

- monomers which are such that the homopolymers prepared from these monomers have Tg values above or equal to 40°C, for example a Tg ranging from 40°C to 150°C, preferably above or equal to 50°C, for example ranging from 50°C to 120°C,

- monomers which are such that the homopolymers prepared from these monomers have Tg values below 40°C, chosen from monomers with a Tg of between 20°C and 40°C and/or monomers with a Tg below or equal to 20°C, for example a Tg ranging from -100°C to 20°C, preferably below 15°C, notably ranging from -80°C to 15°C and better still below 10°C, for example ranging from -50°C to 0°C, as described later.

The first monomers of which the homopolymers have a glass transition temperature above or equal to 40°C are chosen, preferably, from the following monomers, also known as the main monomers:

- the methacrylates of formula CH₂ = C(CH₃)-COOR₁,

wherein R₁ represents a linear or branched unsubstituted alkyl group containing from 1 to 4 carbon atoms, such as a methyl, ethyl, propyl or isobutyl group or R₁ represents a C₄ to C₁₂ cycloalkyl group, preferably a C₈ to C₁₂ cycloalkyl, such as isobornyl methacrylate,

- the acrylates of formula CH₂ = CH-COOR₂

wherein R₂ represents a C₄ to C₁₂ cycloalkyl group such as an isobornyl group or a tert-butyl group,

- (meth)acrylamides of formula:

where:

R₇ and R₈, which may be identical or different, each represent a hydrogen atom or a linear or branched C1 to C12 alkyl group such as an n-butyl, t-butyl, isopropyl, isohexyl, isooctyl or isononyl group; or R₇ represents H and R₈ represents a 1,1-dimethyl-3-oxobutyl group, and

R’ denotes H or methyl.

Examples of monomers that may be mentioned include N-butylacrylamide, N-tert-butylacrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide and N,N-dibutylacrylamide, and mixtures thereof.

The first block is advantageously obtained from at least one acrylate monomer of formula CH₂=CH-COOR₂ and from at least one methacrylate monomer of formula CH₂=C(CH₃)-COOR₂ wherein R₂ represents a C₄ to C₁₂ cycloalkyl group, preferably a C₈ to C₁₂ cycloalkyl, such as isobornyl. The monomers and the proportions thereof are preferably chosen such that the glass transition temperature of the first block is above or equal to 40°C.

According to one embodiment, the first block is obtained from:

i) at least one acrylate monomer of formula CH₂=CH-COOR₂ wherein R₂ represents a C₄ to C₁₂ cycloalkyl group, preferably a C₈ to C₁₂ cycloalkyl group, such as isobornyl,

ii) and at least one methacrylate monomer of formula CH₂ = C(CH₃)-COOR'₂ wherein R'₂ represents a C₄ to C₁₂ cycloalkyl group, preferably a C₈ to C₁₂ cycloalkyl group, such as isobornyl.

According to one embodiment, the first block is obtained from at least one acrylate monomer of formula CH₂=CH-COOR₂ wherein R₂ represents a C₈ to C₁₂ cycloalkyl group, such as isobornyl, and from at least one methacrylate monomer of formula CH₂=C(CH₃)-COOR'₂ wherein R'₂ represents a C₈ to C₁₂ cycloalkyl group, such as isobornyl.

Preferably, R₂ and R'₂ represent, independently or simultaneously, an isobornyl group.

Preferably, the block copolymer comprises from 50% to 80% by weight of isobornyl methacrylate/acrylate, from 10% to 30% by weight of isobutyl acrylate and from 2% to 10% by weight of acrylic acid.

The first block may be obtained exclusively from said acrylate monomer and from said methacrylate monomer.

The acrylate monomer and the methacrylate monomer are preferably in mass proportions of between 30/70 and 70/30, preferably between 40/60 and 60/40 and especially of the order of 50/50.

The proportion of the first block advantageously ranges from 20% to 90%, better still from 30% to 80% and even better still from 60% to 80% by weight of the polymer.

According to one embodiment, the first block is obtained by polymerization of isobornyl methacrylate and isobornyl acrylate.

Second block with a glass transition temperature below 20°C

The second block advantageously has a glass transition temperature Tg below or equal to 20°C, for example, a Tg ranging from -100°C to 20°C, preferably below or equal to 15°C, notably ranging from -80°C to 15°C and better still below or equal to 10°C, for example ranging from -100°C to 10°C, notably ranging from -30°C to 10°C.

The second block is totally or partially derived from one or more second monomers, which are such that the homopolymer prepared from these monomers has a glass transition temperature below or equal to 20°C.

This block may also be referred to as a “flexible block”.

The monomer with a Tg below or equal to 20°C (known as the second monomer) is preferably chosen from the following monomers:

- the acrylates of formula CH₂=CHCOOR₃, with R₃ representing a linear or branched unsubstituted C₁ to C₁₂ alkyl group, with the exception of the tert-butyl group, wherein one or more heteroatoms chosen from O, N and S are optionally intercalated,

- the methacrylates of formula CH₂=C(CH₃)-COOR₄, R₄ representing a linear or branched unsubstituted C₆ to C₁₂ alkyl group, wherein one or more heteroatoms chosen from O, N and S are optionally intercalated,

- the vinyl esters of formula R₅-CO-O-CH=CH₂ wherein R₅ represents a linear or branched C₄ to C₁₂ alkyl group,

- ethers of vinyl alcohol and of a C₄ to C₁₂ alcohol,

- N-(C₄ to C₁₂)alkyl acrylamides, such as N-octylacrylamide,

- and mixtures thereof.

The preferred monomers with a Tg below or equal to 20°C are isobutyl acrylate, 2-ethylhexyl acrylate or mixtures thereof in any proportion.

Each of the first and second blocks may contain in a minor proportion at least one constituent monomer of the other block.

Thus, the first block may contain at least one constituent monomer of the second block, and vice versa.

Each of the first and/or second blocks may comprise, in addition to the monomers indicated above, one or more other monomers known as additional monomers, which are different from the main monomers mentioned previously.

The nature and amount of this or these additional monomer(s) are chosen such that the block in which they are present has the desired glass transition temperature.

This additional monomer is chosen, for example, from:

- ethylenically unsaturated monomers comprising at least one tertiary amine function, for instance 2-vinylpyridine, 4-vinylpyridine, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and dimethylaminopropylmethacrylamide, and salts thereof,

- the methacrylates of formula CH₂=C(CH₃)-COOR₆, wherein R₆ represents a linear or branched alkyl group containing from 1 to 4 carbon atoms, such as a methyl, ethyl, propyl or isobutyl group, said alkyl group being substituted with one or more substituents chosen from hydroxyl groups (for instance 2-hydroxypropyl methacrylate and 2-hydroxyethyl methacrylate) and halogen atoms (Cl, Br, I or F), such as trifluoroethyl methacrylate,

- the methacrylates of formula CH₂=C(CH₃)-COOR₉, R₉ representing a linear or branched C₆ to C₁₂ alkyl group wherein one or more heteroatoms chosen from O, N and S are optionally intercalated, said alkyl group being substituted with one or more substituents chosen from hydroxyl groups and halogen atoms (Cl, Br, I and F),

- the acrylates of formula CH₂=CHCOOR₁₀, R₁₀ representing a linear or branched C₁ to C₁₂ alkyl group substituted with one or more substituents chosen from hydroxyl groups and halogen atoms (Cl, Br, I and F), such as 2-hydroxypropyl acrylate and 2-hydroxyethyl acrylate, or R₁₀ represents a C₁ to C₁₂ alkyl-O-POE (polyoxyethylene) with repetition of the oxyethylene unit 5 to 10 times, for example methoxy-POE, or R₁₀ represents a polyoxyethylenated group comprising from 5 to 10 ethylene oxide units.

In particular, the first block may comprise as additional monomer:

- (meth)acrylic acid, preferably acrylic acid,

- tert-butyl acrylate

- the methacrylates of formula CH₂=C(CH₃)-COOR₁, wherein R₁ represents a linear or branched unsubstituted alkyl group containing from 1 to 4 carbon atoms, such as a methyl, ethyl, propyl or isobutyl group,

- (meth)acrylamides of formula:

where:

R’ denotes H or methyl.

Examples of (meth)acrylamide monomers that may be mentioned include N-butylacrylamide, N-tert-butylacrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide and N,N-dibutylacrylamide, and mixtures thereof.

The additional monomer may represent 0.5% to 30% by weight relative to the weight of the polymer. According to one embodiment, the polymer of the invention does not contain any additional monomer.

Preferably, the polymer of the invention comprises at least isobornyl acrylate and isobornyl methacrylate monomers in the first block and isobutyl acrylate and acrylic acid monomers in the second block.

Preferably, the polymer comprises at least isobornyl acrylate and isobornyl methacrylate monomers in equivalent weight proportion in the first block and isobutyl acrylate and acrylic acid monomers in the second block.

Preferably, the polymer comprises at least isobornyl acrylate and isobornyl methacrylate monomers in equivalent weight proportion in the first block, and isobutyl acrylate and acrylic acid monomers in the second block, the first block representing 70% of the weight of the polymer.

Preferably, the polymer comprises at least isobornyl acrylate and isobornyl methacrylate monomers in equivalent weight proportion in the first block and isobutyl acrylate and acrylic acid monomers in the second block. Preferably, the block with a Tg above 40°C represents 70% by weight of the polymer, and acrylic acid represents 5% by weight of the polymer.

According to one embodiment, the first block does not comprise any additional monomer.

According to a preferred embodiment, the second block comprises acrylic acid as additional monomer. In particular, the second block is advantageously obtained from an acrylic acid monomer and from at least one other monomer with a Tg below or equal to 20°C.

According to a preferred embodiment, the composition according to the invention comprises at least one copolymer comprising at least one acrylate monomer of formula CH₂ = CH-COOR₂ wherein R₂ represents a C₈ to C₁₂ cycloalkyl group and/or at least one methacrylate monomer of formula CH₂=C(CH₃)-COOR’₂ wherein R’₂ represents a C₈ to C₁₂ cycloalkyl group, at least one second acrylate monomer of formula CH₂=CHCOOR₃, wherein R₃ is a linear or branched unsubstituted C₁ to C₁₂ alkyl group, with the exception of the tert-butyl group, and at least one acrylic acid monomer.

Preferably, the copolymer used in the compositions according to the invention is obtained from at least one isobornyl methacrylate monomer, at least one isobornyl acrylate monomer, at least one isobutyl acrylate monomer and at least one acrylic acid monomer; in particular, it is chosen from the polymers having the INCI name Acrylic Acid/Isobutyl Acrylate/Isobornyl Acrylate copolymer in their solid form, such as those of the commercial products Mexomer PAS® and Mexomer PAZ® produced and sold by Noveal.

Advantageously, the copolymer used in the invention comprises from 50% to 80% by weight of isobornyl methacrylate/acrylate mixture, from 10% to 30% by weight of isobutyl acrylate and from 2% to 10% by weight of acrylic acid.

The block copolymer may advantageously comprise more than 2% by weight of acrylic acid monomers, and notably from 2% to 15% by weight, for example from 3% to 15% by weight, in particular from 4% to 15% by weight or even from 4% to 10% by weight of acrylic acid monomers, relative to the total weight of said copolymer.

The constituent monomers of the second block and the proportions thereof are chosen such that the glass transition temperature of the second block is less than or equal to 20°C.

Intermediate segment

The intermediate segment (also known as the intermediate block) connects the first block and the second block of the polymer used according to the present invention. The intermediate segment results from the polymerization:

i) of the first monomer(s), and optionally of the additional monomer(s), which remain available after their polymerization to a maximum degree of conversion of 90% to form the first block,

ii) and of the second monomer(s), and optionally of the additional monomer(s), added to the reaction mixture.

The formation of the second block is initiated when the first monomers no longer react or are no longer incorporated into the polymer chain either because they are all consumed or because their reactivity no longer allows them to be.

Thus, the intermediate segment comprises the first monomers that are available, resulting from a degree of conversion of these first monomers of less than or equal to 90%, during the introduction of the second monomer(s) during the synthesis of the polymer.

The intermediate segment of the block polymer is a statistical polymer (which may also be referred to as a statistical block). This means that it comprises a statistical distribution of the first monomer(s) and of the second monomer(s) and also of the additional monomer(s) that may be present.

Thus, the intermediate segment is a statistical block, as are the first block and the second block if they are not homopolymers (i.e. if they are both formed from at least two different monomers).

Process for preparing the copolymer:

The block ethylenic copolymer according to the invention is prepared by free radical polymerization, according to the techniques that are well known for this type of polymerization.

The free radical polymerization is performed in the presence of an initiator, the nature of which is adapted, in a known manner, as a function of the desired polymerization temperature and of the polymerization solvent. In particular, the initiator may be chosen from initiators bearing a peroxide function, redox couples or other free radical polymerization initiators known to those skilled in the art.

In particular, examples of initiators bearing a peroxide function that may be mentioned include:

a) peroxyesters such as tert-butyl peroxyacetate, tert-butyl perbenzoate, tert-butyl peroxy-2-ethylhexanoate (Trigonox 21S® from AkzoNobel) or 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane (Trigonox 141 from AkzoNobel);

b) peroxydicarbonates such as diisopropyl peroxydicarbonate;

c) peroxy ketones such as methyl ethyl ketone peroxide;

d) hydroperoxides such as aqueous hydrogen peroxide solution (H₂O₂) or tert-butyl hydroperoxide;

e) diacyl peroxides such as acetyl peroxide or benzoyl peroxide;

f) dialkyl peroxides such as di-tert-butyl peroxide;

g) inorganic peroxides such as potassium peroxodisulfate (K₂S₂O₈).

As initiator in the form of a redox couple, mention may be made of the potassium thiosulfate + potassium peroxodisulfate couple, for example.

According to a preferred embodiment, the initiator is chosen from organic peroxides comprising from 8 to 30 carbon atoms. Preferably, the initiator used is 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane sold under the reference Trigonox® 141 by AkzoNobel.

The block copolymer used according to the invention is prepared by free radical polymerization and not by controlled or living polymerization. In particular, the polymerization of the block ethylenic copolymer is performed in the absence of control agents, and in particular in the absence of control agents conventionally used in living or controlled polymerization processes, such as nitroxides, alkoxyamines, dithioesters, dithiocarbamates, dithiocarbonates or xanthates, trithiocarbonates or copper-based catalysts, for example.

Block copolymers such as those described previously are notably described in patent applications EP-A-1411069 and EP-A-1882709.

The synthetic solvent used for the polymerization of the film-forming copolymer is generally chosen from volatile oils with a flash point below 80°C, for instance isododecane.

Polysaccharides grafted with organosiloxane groups

Among the polysaccharides grafted with organosiloxane groups, mention may be made of the polysaccharides obtained by reaction of

a) a polysaccharide with

b) an organopolysiloxane comprising an isocyanate group of formula (1) below:

wherein R¹, R², R³and R⁴ independently represent a radical chosen from an alkyl group having from 1 to 8 carbon atoms, a fluoroalkyl group having from 1 to 8 carbon atoms and an aryl group having from 6 to 12 carbon atoms; n is an integer from 1 to 10 and a is an integer from 0 to 3; and

c) an organic compound comprising an isocyanate group of formula (2) below:

wherein R⁵ represents an alkyl group having from 3 to 30 carbon atoms, an aryl group having from 6 to 12 carbon atoms or an aralkyl group having from 6 to 30 carbon atoms or a group of formula (3) below:

wherein R⁶ represents a divalent hydrocarbon group having from 2 to 8 carbon atoms; R₇ is an alkyl group having from 1 to 30 carbon atoms; X denotes an -NHCONH or NHCOO- group.

The polysaccharide is preferably chosen from pullulans, celluloses, chitins, chitosans, starches, mannans, hyaluronic acid and forms thereof modified by alkylation, acylation, cationization or addition of a polyoxyalkylenated chain. More particularly, it is chosen from a pullulan or a cellulose, in particular a hydroxypropylcellulose.

The organopolysiloxane comprising an isocyanate group of formula (1) is preferably chosen from the compound having the formula below:

The organic compound comprising an isocyanate group of formula (2) is preferably chosen from stearyl isocyanate or a compound having the structure:

These polysaccharides grafted with organosiloxane groups and also the synthesis thereof are described in patents EP 2647366B1 and KR10-1666267B1 and application WO2023/068123.

Among the polysaccharides grafted with organosiloxane groups, use will be made of the polymer having the INCI name Trimethylsiloxysilylcarbamoyl Pullulan in the solid state, such as that in the product sold under the trade name TSPL-30-ID® or the product TSPL-30-D5® by Shin Etsu.

Polysaccharide ethers

The term “polysaccharide ether” is understood to mean an alkyl polysaccharide of which the alkyl group comprises from 1 to 30, preferably from 2 to 10, more preferentially from 2 to 6 carbon atoms.

Preferably, the alkyl polysaccharides according to the invention are cellulose derivatives, pullulan derivatives or guar derivatives, or mixtures thereof.

According to a particular embodiment, the alkyl polysaccharide(s) is (are) chosen from alkyl celluloses of which the linear or branched alkyl group comprises from 1 to 20 carbon atoms, in particular from 2 to 15 carbon atoms.

The alkyl cellulose is a cellulose alkyl ether comprising a chain constituted of β-anhydroglucose units linked together via acetal bonds. Each anhydroglucose unit contains three replaceable hydroxyl groups, all or some of these hydroxyl groups being able to react according to the following reaction:

Cell-OM + R-Hal → Cell-OR + MHal

with Hal representing a halogen such as Cl, with M representing a cationic counterion, such as an alkali metal Na or K, or an alkaline-earth metal, preferably an alkali metal, such as Na, Cell representing a polysaccharide radical, such as cellulose, R representing a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 2 to 3 carbon atoms, such as methyl or ethyl, and MHal representing the salt generated, such as sodium chloride.

[0067] Advantageously, the compound(s) E is (are) chosen from ethyl cellulose, propyl cellulose and mixtures thereof, preferably ethyl cellulose.

The ethyl cellulose polymers used in a cosmetic composition according to the invention are preferentially polymers with a degree of substitution with ethoxy groups ranging from 2.5 to 2.6 per anhydroglucose unit, in other words comprising a content of ethoxy groups ranging from 44% to 50%.

The average molar mass of the ethyl cellulose is preferably chosen such that the viscosity of a 5% by weight solution in a mixture of 80/20 (toluene/ethanol) at 25°C ranges from 4 to 300 mPa.s, preferably from 5 to 200 mPa.s, for example from 5 to 150 mPa.s (standard ASTM D 914).

The ethyl cellulose used in the composition according to the invention is more particularly in pulverulent form.

It is, for example, sold under the Ethocel Standard® trade names by Dow Chemicals, with in particular Ethocel Standard 7 FP Premium® and Ethocel Standard 100 FP Premium®. Other commercially available products, such as those sold by Ashland, Inc. under the names Aqualon Ethylcellulose® type-K, type-N and type-T, preferably type-N, such as N7, N100, are particularly suitable for performing the invention.

According to another particular embodiment, the polysaccharide ether(s) is (are) chosen from alkyl guars, i.e. guar gums modified by substitution of hydroxyl hydrogen with a linear or branched alkyl group comprising from 1 to 20 carbon atoms, in particular from 2 to 10 carbon atoms, preferably from 2 to 3 carbon atoms such as 2 carbon atoms. Advantageously, the alkyl polysaccharide is ethyl guar. Ethyl guar is known under the INCI name: C1-5 Alkyl Galactomannan, such as the commercial products ASI D-5783 Modified Polysaccharide Ethyl Guar® and N Hance AG 200 sold by Ashland, and the commercial product Lanco-GEL CP 5® sold by Langer.

According to another particular embodiment, the polysaccharide ether(s) is (are) chosen from alkyl pullulans, for instance myristoyl pullulan, such as the commercial product Myristoyl Pullulan® sold by Katakura Chikkarin.

Norbornene polymers grafted with organosiloxane groups

Among norbornene polymers grafted with organosiloxane groups, mention may be made of norbonene resins modified with a linear, branched or monocyclic organosiloxane as described in patent JP4475413B2.

They correspond to the formula below:

wherein R¹ to R¹⁶, which may be identical or different, represent a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, a hydroxyl group, a carboxyl group, an acyloxy group having 1 to 10 carbon atoms, an organooxycarbonyl group having 2 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, a cyano group, an amide group, an imide group or

a group (SiR¹⁹)₃wherein R¹⁹ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, an organooxy group having 1 to 10 carbon atoms, an amide group, an imide group or

a group O(SiR²⁰ ₂O)_pSiR²⁰ ₃ wherein R²⁰ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and p is an integer from 0 to 20; it being possible for the acid anhydride groups to be identical to or different from one another, and two groups R¹ to R¹⁶ may form an acid anhydride group;

R¹⁷ is a hydrogen atom or a monovalent hydrocarbon group having from 1 to 10 carbon atoms;

R¹⁸ is a single bond;

X is the formula: -(SiR²¹ ₂O)_qSiR²¹ ₃-Si(OSiR²² ₃)_rR²⁰ _3-r where R²⁰ is a substituted or unsubstituted monovalent hydrocarbon group having from 1 to 10 carbons, and R²¹ are substituted or unsubstituted monovalent hydrocarbon groups having from 1 to 20 carbons, which may be identical to or different from one another and R²² is R²¹ or a group (OSiR²¹ ₂)_sR²¹ where s is an integer from 0 to 20,

q is an integer from 1 to 100,

r is 2 or 3, and t is an integer from 0 to 10,

m is 0.1 or 2;

n is an integer from 10 to 1 000 000.

Among these polymers, mention may be made in particular of that having the INCI name: Norbornene/Tris(Trimethylsiloxy) Silylnorbornene in the solid state, such as that in trade product NBN-30-ID® sold by Shin Etsu.

Volatile solvent

The composition of the invention comprises at least one volatile solvent in which said film-forming polymer is solubilized.

For the purposes of the invention, the term “volatile solvent” is understood to mean any liquid chemical compound that is capable of solubilizing said film-forming polymer and that is capable of evaporating on contact with the skin in less than one hour, at room temperature and atmospheric pressure. The volatile solvent is a volatile cosmetic compound, which is liquid at room temperature, notably having a non-zero vapour pressure, at room temperature and atmospheric pressure, notably having a vapour pressure ranging from 2.66 Pa to 40 000 Pa, in particular ranging from 2.66 Pa to 13 000 Pa and more particularly ranging from 2.66 Pa to 1300 Pa.

The volatile solvent(s) is (are) present in the composition of the invention in a total amount sufficient for solubilizing the film-forming polymer(s) present in said composition.

According to a preferential form, the composition of the invention comprises the volatile solvent(s) in a content ranging from 10% to 70% by weight, more preferentially ranging from 20% to 50% by weight relative to the total weight of the composition.

Volatile oils

According to a particular embodiment of the invention, the volatile solvent(s) is (are) organic, and more particularly is (are) chosen from volatile oils.

The term “oil” means any fatty substance that is in liquid form at room temperature (20-25°C) and atmospheric pressure (760 mmHg).

For the purposes of the invention, the term “volatile oil” refers to any oil that is capable of evaporating on contact with the skin in less than one hour, at room temperature and atmospheric pressure. The volatile oil is a volatile cosmetic compound, which is liquid at room temperature, notably having a non-zero vapour pressure, at room temperature and atmospheric pressure, notably having a vapour pressure ranging from 2.66 Pa to 40 000 Pa, in particular ranging from 2.66 Pa to 13 000 Pa and more particularly ranging from 2.66 Pa to 1300 Pa.

The volatile oil(s) may be chosen from hydrocarbon oils and silicone oils, and mixtures thereof.

For the purposes of the present invention, the term “silicone oil” is understood to mean an oil formed of a silicon-oxygen chain -Si-O-Si-O-Si-O in which organic groups attach to the silicon atoms.

For the purposes of the present invention, the term “hydrocarbon oil” is understood to mean an oil comprising at least carbon atoms and hydrogen atoms and optionally, in addition, oxygen, nitrogen, sulfur and/or phosphorus atoms, for example in the form of hydroxyl or acid radicals.

a) Volatile hydrocarbon oils

The volatile hydrocarbon oils that can be used in the compositions (A) according to the invention may be chosen from branched C8-C16 alkanes.

Mention may notably be made of C8-C16 isoalkanes of petroleum origin (also known as isoparaffins), such as isododecane (also known as 2,2,4,4,6-pentamethylheptane), isodecane, isohexadecane and, for example, the oils sold under the Isopar® or Permethyl® trade names.

Mention may also be made of branched C8-C16 esters such as isohexyl neopentanoate. Other volatile hydrocarbon oils, such as petroleum distillates, in particular those sold under the name Shell Solt® by Shell, can also be used.

The volatile hydrocarbon oils which can be used in the compositions according to the invention can be chosen from volatile linear alkanes comprising from 6 to 14 carbon atoms.

Mention may be made, as examples of linear alkanes suitable for the invention, of the alkanes described in the patent applications of Cognis WO 2007/068371 or WO 2008/155059 (mixtures of different alkanes differing by at least one carbon). These alkanes are obtained from fatty alcohols, which are themselves obtained from coconut kernel oil or palm oil.

As examples of linear C6-C14 alkanes that are suitable for use in the invention, mention may be made of n-hexane (C6), n-heptane (C7), n-octane (C8), n-nonane (C9), n-decane (C10), n-undecane (C11), n-dodecane (C12), n-tridecane (C13) and n-tetradecane (C14), and mixtures thereof.

Mention may notably be made of n-dodecane (C12) and n-tetradecane (C14) sold by Sasol under the references, respectively, Parafol 12-97® and Parafol 14-97®, and also mixtures thereof.

According to another embodiment, a mixture of n-dodecane and n-tetradecane is used. Use may in particular be made of the dodecane/tetradecane mixture in the 85/15 weight ratio sold by Biosynthis under the reference Vegelight 1214®.

According to yet another embodiment, use is made of a mixture of volatile linear C9-C12 alkanes with the INCI name: C9-12 Alkane, such as the product sold by Biosynthis under the reference Vegelight Silk®.

According to yet another embodiment, use is made of a mixture of n-undecane (C11) and of n-tridecane (C13), such as those obtained in Examples 1 and 2 of application WO 2008/155059 from Cognis and such as that sold under the trade name Cetiol Ultimate® by BASF.

b) Volatile silicone oils

Volatile silicone oils that may also be used include volatile silicones, for instance volatile linear or cyclic silicone oils, in particular those with a viscosity ≤ 5 centistokes (5 mm²/s), and in particular containing from 2 to 10 silicon atoms and preferably from 2 to 7 silicon atoms, these silicones optionally comprising alkyl or alkoxy groups containing from 1 to 10 carbon atoms. Mention may in particular be made, as volatile silicone oil which can be used in the invention, of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, heptamethylhexyltrisiloxane, heptamethyloctyltrisiloxane, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane and mixtures thereof.

According to one particularly preferred embodiment, the volatile solvent is a volatile hydrocarbon oil chosen from branched C8-C16 alkanes, and more particularly is isododecane.

Galenical forms

The care and/or makeup compositions according to the invention may be chosen from gels, creams, milks and lotions.

The care and/or makeup compositions according to the invention may be anhydrous formulations or aqueous formulations. They may be liquid or solid, such as hot-cast products or loose or compact powders.

The term “anhydrous” means that the composition contains less than 5% by weight of water relative to the total weight of the composition, or even less than 1% by weight, or even is free of water, water not being added during the preparation of the composition, but corresponding to the residual water supplied by the ingredients in the form of a mixture.

The care and/or makeup compositions according to the invention may be chosen from aqueous dispersions, oily compositions, or multiphase compositions such as emulsions, for instance oil-in-water emulsions, water-in-oil emulsions, or two- or three-phase compositions, notably two-phase gels also referred to as gel/gel compositions such as those described in patents EP2958540B1, EP2958541B1, EP3185958B1.

Suitable care and/or makeup compositions according to the invention may contain one or more compounds which are well known to those skilled in the art and generally present in foundations.

The care and/or makeup compositions according to the invention may additionally comprise additives commonly used in care and/or makeup products, such as:

- active agents, for instance moisturizers such as hydroxyethyl urea, vitamins, for example vitamins A, E, C and B3, adenosine, and hyaluronic acid and salts thereof;

- ceramides;

- UV screening agents;

- water-soluble dyes, fat-soluble dyes;

- hydrophilic gelling agents;

- lipophilic gelling agents;

- fillers;

- fragrances;

- preserving agents;

- and mixtures thereof.

Such compositions are in particular prepared according to the general knowledge of a person skilled in the art.

According to a particular embodiment, the composition according to the invention is a skincare product, in particular an anti-sun product, a product for oily skin, a product for dry skin or an anti-ageing product.

According to a particular embodiment, the composition according to the invention is a makeup product for the face such as a foundation; a makeup product for the eyelids, such as an eyeshadow; a makeup product for the cheeks, such as a face powder; a makeup product for the lips, such as lipsticks; a makeup product for the eyelashes or the eyebrows, such as mascaras or eyeliners.

Obviously, those skilled in the art will adapt the nature of the compounds of the composition by using their common general knowledge to prepare a composition which can be used in the context of the invention.

For the high-viscosity compositions, such as thick creams, the viscosity, measured at 25°C and under atmospheric pressure, is greater than or equal to 4.5 Pa.s at a shear rate of 200 s^-1 and less than or equal to 50 Pa.s (using a Brookfield Rheomat RM 180® viscometer equipped with a No. 4 spindle, the measurement being effected after 10 minutes of rotation of the spindle in order to stabilize the rotational speed and the viscosity).

For the more fluid compositions, the viscosity may be less than 4.5 Pa.s, for example between 1 mPa.s (or 1 cps) and 4.5 Pa.s at a shear rate of 200 s^-1 (using a Brookfield Rheomat RM 180® viscometer equipped with a No. 4 spindle, the measurement being effected after 10 minutes of rotation of the spindle in order to stabilize the rotational speed and the viscosity).

Manufacturing process

Another subject of the invention relates to a process for producing a care and/or makeup composition as defined above, comprising at least one step of milling said film-forming polymer with at least one portion of the pulverulent phase, in particular the particulate colorants present in the composition.

The mixing step b) may be carried out at room temperature (25°C) and atmospheric pressure with a Hauschild Speedmixer® planetary mixer for a time ranging preferably from 5 to 15 minutes.

The colorant(s) may be chosen from those described previously, and in particular are chosen from pigments and more particularly are chosen from titanium dioxides, iron oxides (black, yellow or red), and mixtures thereof; said pigments optionally comprising at least one lipophilic or hydrophobic coating.

Another subject of the invention also relates to a composition for caring for and/or making up keratin materials as defined previously comprising at least one particulate colorant formulation as defined previously.

The pulverulent phase, the film-forming polymer and the optional additional ingredients are mixed dry, in proportions in accordance with the invention, then part or all of the pulverulent phase and the film-forming polymer are subjected to a dry milling step. Among the various dry milling processes, use may be made of powder mill-micronizers operating by friction or collision or a combination thereof, making it possible to obtain very fine milling grades

(D50 < 10 µm), such as an air (or inert gas) jet mill, a pin mill or a knife mill.

The term “mill-micronizer” according to the invention means a mill making it possible to refine particles to sizes of the order of a few microns, or even of the order of one micron, or even smaller. As commercial references for mills for dry milling, mention may be made in particular of the Chrispro Jet Mill® air jet mill manufactured by Micro-45 Macinazione S.A. (Italy), the Hosokawa® pin mill supplied by Alpine A. G. (Germany), and the IKA M20® knife mill, sold by IKA Werke GmbH & Co. KG (Germany).

In particular, it is possible to use air jet, pin or knife mills, more preferentially a pin mill or a knife mill will be used, preferably a pin mill.

According to a particular embodiment of the invention, the particulate colorant formulation that can be obtained according to this preparation process of the invention has a particle size profile with a D50 ranging from 1 to 15 µm, and preferentially from 1 to 10 µm.

The particle size analysis of the particulate colorant formulation is generally carried out by simple dispersion of said particles in a liquid dispersant and is measured at 25°C for example using a laser particle sizer, according to the recommendations of the supplier.

Kit

According to another aspect, the invention also relates to a cosmetic kit comprising:

i) a container delimiting one or more compartments, said container being closed by a closing member; and

ii) a makeup and/or care composition in accordance with the invention placed inside said compartment(s).

The container may be, for example, in the form of a pot or a casing.

The closing member may be in the form of a lid or a tear-off cover. In particular, this closing member may comprise a lid mounted so as to be able to move by translation or by pivoting relative to the container housing said makeup and/or care composition(s).

It is understood that, in the context of the present invention, the weight percentages given for a compound or a family of compounds are always expressed by weight relative to the total weight of the composition.

Throughout the patent application, the term “comprises a” should be understood as meaning “comprising at least one”, unless otherwise specified.

It is understood that the examples which follow are present by way of illustration and that they do not in any way limit the scope of the protection conferred by the present patent application.

Examples

Example 1 - pigment preparation according to the invention

The following composition was prepared according to the following procedure:

Ingredients	Example 1 (invention)
Pigments Titanium dioxide coated with aluminium stearoyl glutamate (68.5%) Yellow iron oxide coated with aluminium stearoyl glutamate (25%) Red iron oxide coated with aluminium stearoyl glutamate (5%) Black iron oxide coated with aluminium stearoyl glutamate (1.5%)	70
Resin Trimethylsiloxysilicate in solid form	30

Protocol for preparing Example 1 - pigment preparation:

The trimethylsiloxysilicate resin in solid form and the pigments were premixed with a spatula, then 50 grams of the mixture were milled for 15 seconds using an IKA M20® knife mill sold by IKA Werke GmbH & Co. KG (Germany). The lid was then opened, the edges and the lid and also the milling chamber were scraped with the brush to check that there was no agglomeration (powder stuck to the walls). Then another 15 seconds of milling were performed.

Example 2 (invention) and Example 2a (outside the invention) - foundation

The following compositions were prepared according to the following procedures.

Ingredients	Example 2 (invention)
Pigment preparation of Example 1 comprising 15% by weight of active material of trimethylsiloxysilicate	50
Isododecane	50

Ingredients	Example 2a (outside the invention)
Pigments Titanium dioxide coated with aluminium stearoyl glutamate (68.5%) Yellow iron oxide coated with aluminium stearoyl glutamate (25%) Red iron oxide coated with aluminium stearoyl glutamate (5%) Black iron oxide coated with aluminium stearoyl glutamate (1.5%)	35
Resin Trimethylsiloxysilicate in solid form	15
Isododecane	50

Protocol for preparing Example 2 (invention) and Example 2a outside the invention:

The ingredients are introduced into a stainless steel dish, then mixed with a spatula for 10 seconds. The results are indicated in the following table:

Evaluation	Example 2 (invention)	Example 2a (outside the invention)
Appearance of the composition	Homogeneous mixture. No formation of aggregate.	Formation of resin aggregate stuck to the spatula.

It was observed that Example 2 according to the invention using a pigment formulation obtained according to the process according to the invention makes it possible to obtain a homogeneous foundation, unlike Example 2a outside the invention obtained according to another preparation process.

Claims

Process for preparing a composition, notably for coating keratin materials, more particularly for making up and/or caring for keratin materials, such as the skin, notably comprising a physiologically acceptable medium and containing at least:
a) a pulverulent phase, and
b) at least one volatile solvent,
c) at least one film-forming polymer in solubilized form in said volatile solvent, comprising at least one step of milling said film-forming polymer in solid form with at least one portion of the pulverulent phase of the composition.
Process according to Claim 1, where the composition has a content of pulverulent phase of greater than or equal to 5% by weight, in particular greater than or equal to 10% by weight and more particularly ranging from 12% to 40% by weight relative to the total weight of the composition.
Process according to Claim 1 or 2, where the pulverulent phase of the composition comprises at least one filler and/or at least one particulate colorant.
Process according to Claim 3, where the filler(s) is (are) present in a content ranging from 0% to 15% by weight, more preferentially from 1% to 10% by weight, relative to the total weight of the composition.
Process according to Claim 3 or 4, where the filler(s) is (are) present in a content ranging from 0% to 50% by weight, more preferentially from 10% to 40% by weight, relative to the total weight of the pulverulent phase.
Process according to Claim 3, where the content of particulate colorant(s) varies from 5% to 90% by weight, and preferentially ranges from 10% to 70% by weight relative to the total weight of the composition.
Process according to Claim 3, where the pulverulent phase comprises a content of particulate colorant(s) preferably ranging from 5% to 100% by weight, and preferentially ranging from 10% to 75% by weight relative to the total weight of the pulverulent phase.
Process according to any one of Claims 3, 6 and 7, where the particulate colorant(s) is (are) chosen from pigments, nacres, reflective particles and mixtures thereof, and more particularly chosen from titanium dioxides, iron oxides and mixtures thereof; said pigments optionally comprising at least one lipophilic or hydrophobic coating.
Process according to any one of the preceding claims, where the composition comprises from 5% to 60% by weight, more preferentially from 10% to 50% by weight, more particularly from 20% to 40% by weight, of active material of film-forming polymer(s) in solubilized form relative to the total weight of the composition.
Process according to any one of the preceding claims, where the film-forming polymer(s) is (are) hydrophobic, in particular liposoluble.
Process according to any one of the preceding claims, where the hydrophobic film-forming polymer(s) is (are) chosen from:
- a silicone resin;
- a copolymer comprising carboxylate groups and polydimethylsiloxane groups;
- a vinyl polymer comprising at least one carbosiloxane dendrimer-based unit;
- an ethylene block copolymer;
- a polysaccharide grafted with organosiloxane groups;
- a polysaccharide ether;
- a norbornene polymer grafted with organosiloxane groups;
- mixtures thereof.
Process according to Claim 11, where the silicone resin is trimethylsiloxysilicate.
Process according to Claim 11, where the copolymer comprising carboxylate groups and polydimethylsiloxane groups is chosen from the products with the INCI name: ACRYLATES/ETHYLHEXYL ACRYLATE/DIMETHICONE METHACRYLATE in solid form.
Process according to Claim 11, where the vinyl polymer comprising at least one carbosiloxane dendrimer-based unit is chosen from the product with the INCI name: ACRYLATES/POLYTRIMETHYLSILOXYMETHACRYLATE in solid form.
Process according to Claim 11, where the ethylene block copolymer is obtained from at least one isobornyl methacrylate monomer, at least one isobornyl acrylate monomer, at least one isobutyl acrylate monomer and at least one acrylic acid monomer, and in particular is chosen from polymers with the INCI name: ACRYLIC ACID/ISOBUTYL ACRYLATE/ISOBORNYL ACRYLATE COPOLYMER POLYTRIMETHYLSILOXYMETHACRYLATE in solid form.
Process according to Claim 11, where the polysaccharide grafted with organosiloxane groups is the product with the INCI name: TRIMETHYLSILOXYSILYLCARBAMOYL PULLULAN in solid form.
Process according to Claim 11, where the polysaccharide ether is chosen from ethyl cellulose, ethyl guar and myristoyl pullulan.
Process according to Claim 11, where the norbornene polymer grafted with organosiloxane groups is the product with the INCI name: NORBORNENE/TRIS(TRIMETHYLSILOXY) SILYLNORBORNENE in solid form.
Process according to any one of the preceding claims, where the volatile solvent(s) is (are) organic, in particular chosen from volatile oils, and more particularly chosen from volatile hydrocarbon oils, volatile silicone oils and mixtures thereof.
Process according to any one of the preceding claims, where the composition of the invention comprises the volatile solvent(s) in a content ranging from 10% to 70% by weight, more preferentially ranging from 20% to 50% by weight relative to the total weight of the composition.
Process for manufacturing a composition according to any one of Claims 3, 6 to 20, in which the pulverulent phase contains at least one or more particulate colorant(s), comprising at least the following steps:
a) preparing a particulate colorant formulation comprising said particulate colorant(s) and at least one film-forming polymer in solid form by milling said film-forming polymer with a portion or all of the particulate colorant(s); and
b) mixing said volatile solvent with the particulate colorant formulation thus obtained.
Composition that can be obtained by the process according to any one of Claims 1 to 21.
Particulate colorant formulation that can be obtained according to step a) of the process according to Claim 21.
Care and/or makeup composition comprising at least one particulate colorant formulation according to Claim 23.
Cosmetic kit comprising:
i) a container delimiting one or more compartments, said container being closed by a closing member; and
ii) a composition that can be obtained by the process according to any one of Claims 1 to 21 or a composition according to Claim 23 or 24 arranged inside said compartment(s).
Process for coating keratin materials, more particularly for making up and/or caring for keratin materials, such as the skin, characterized in that it comprises the application, to the keratin materials, of a composition that can be obtained by the process according to any one of Claims 1 to 21 or of a composition according to Claim 23 or 24.